A hard-hitting video investigation into China's grave air pollution problem has been pulled from mainstream video sites, days after it garnered more than 150 million hits online.
"Under the Dome", an independent documentary produced by former Chinese state media journalist Chai Jing, was no longer available on popular mainland video sites, including Youku and iQiyi, as of Saturday afternoon.
A link on Youku's website that previously led to the video now prompts the message: "We're very sorry, Youku was unable to find the page you requested."
The 103-minute documentary ?- hailed by some as China's "Inconvenient Truth" -- remains available on YouTube, which is blocked in China.
Versions of the video had racked up more than 155 million views on mainland Chinese video streaming sites just one day after its release last Saturday.
In the video, Chai, who previously worked as an anchor for state-run China Central Television, detailed causes of atmospheric pollution in the country, including slack government supervision and lenient penalties for polluters.
She has described the video as her "personal battle" against air pollution after her daughter was born with a benign tumour.
The removal of the documentary underscores the ruling Communist Party's sensitivity to public debate over China's notorious smog problem.
It also represents a sharp turnaround by Chinese authorities, who only days ago encouraged ubiquitous coverage of the video in official print and broadcast media.
China's newly-appointed environmental protection minister, Chen Jining, praised the video earlier this week, telling Chinese reporters that it should "encourage efforts by individuals to improve air quality".
The video's disappearance comes as the country's top annual political meeting, the National People's Congress (NPC), is underway in Beijing, under thick white skies and with the city's air quality registering as "very unhealthy", according to a US embassy reading.
Online discussions related to the video remain unblocked on China's popular social networks, and users of China's Twitter-like Sina Weibo on Saturday voiced frustration with the government's abrupt censorship move.
"Chai Jing's documentary, 'Under the Dome', has already been 'harmonised' on all of the mainstream video sites," wrote one user on Sina Weibo, using an ironic term for authorities' blocking of objectionable content. "Why? Give us a reason first!"
"When will this country be able to face the attitudes of its own people?" another Sina Weibo user wrote.
- 'Iron hand' -
China's cities are often hit by heavy pollution, blamed on coal-burning by power stations and industry, as well as vehicle use, and it has become a major source of popular discontent with the Communist Party, leading the government to declare a "war on pollution" and vow to reduce the proportion of energy derived from fossil fuels.
Chen, the environmental protection minister, Chen held an hour-long news conference Saturday afternoon on the sidelines of the NPC.
But out of a dozen questions asked -- mostly by Chinese state-run media outlets -- not a single one focused on the documentary.
NPC press conferences are usually highly stage-managed by Chinese authorities, with organizers pre-approving both the order of questions as well as the questions themselves.
Chen did make a reference to "APEC blue" -- a tongue-in-cheek phrase that became popular online during the Asia-Pacific Economic Cooperation summit in November, when Beijing shut down factories and enacted strict regulations to ensure a blue sky for visiting dignitaries.
"From international experience and the process of bringing about 'APEC blue', we can see that if we want to significantly improve our air quality, we cannot rely on heaven alone; we must bring down our emissions levels," Chen said.
"Can it be done?" he asked. "It can, but it's very difficult indeed, and it will require us all to make an extra effort."
Read more at Discovery News
Mar 7, 2015
Rover Opportunity Has Found Some Odd Mars Rocks
Veteran Mars rover Opportunity is on the verge of completing a marathon on Mars, but before it crosses the imaginary finishing line at “Marathon Valley,” the plucky six-wheeled robot has found some odd rocks that require further investigation.
“We drove to the edge of a plateau to look down in the valley, and we found these big, dark-gray blocks along the ridgeline,” said Matt Golombek, Opportunity Project Scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We checked one and found its composition is different from any ever measured before on Mars. So, whoa! Let’s study these more before moving on.”
Marathon Valley is so-called as when the rover rolls into the area, it will have completed the distance of a marathon on Mars — 26 miles and 385 yards, or 42.195 kilometers. At its current location, Opportunity is a mere 128 meters from completing that distance.
Apart from being a momentous location for Opportunity’s epic 11 year-long exploration of the red planet, the valley also contains clay minerals as discerned from satellite spectroscopic data; clays that contain invaluable insights to Mars’ wet past. But it seems that the entrance to Marathon Valley is just as enticing as the valley itself promises.
One of the strange-looking blocks has been nicknamed “Jean-Baptiste Charbonneau” and, using its robotic arm-mounted Alpha Particle X-ray Spectrometer instrument, the rover has determined that the rock contains “relatively high concentrations of aluminum and silicon,” unlike any other rock sample analyzed by Opportunity or sister rover Spirit (that was sadly lost in 2010 after becoming stuck in a sand trap in Gusev Crater).
Opportunity’s science team has now selected another rock in the area, named “Sergeant Charles Floyd,” for additional analysis. The naming convention for these two rocks were inspired by the Lewis and Clark Expedition that ventured across Western portion of what is now the United States in the early 19th Century.
According to a NASA JPL news release, the rocks are gray, but the visible light spectrum of Charbonneau is more purple than most Mars rocks, whereas Floyd is more blue. The bluer rocks appear to lie higher on the ridge.
After analyzing Charbonneau, Opportunity’s mission team uploaded new software to the rover’s computer that is now instructing the rover to avoid writing data to a corrupt bank in the rover’s flash memory. It is now only writing data to 6 of the 7 banks in the hope that Opportunity’s “amnesia events” can be remedied.
Since late 2014, Opportunity has been in “no flash mode”, instead only using its volatile memory that is wiped every day. Lack of flash memory and frustrating rover resets have slowed progress in recent months, but with this new upgrade, mission engineers hope that Opportunity can shrug off these age-related issues and soldier on.
Read more at Discovery News
“We drove to the edge of a plateau to look down in the valley, and we found these big, dark-gray blocks along the ridgeline,” said Matt Golombek, Opportunity Project Scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We checked one and found its composition is different from any ever measured before on Mars. So, whoa! Let’s study these more before moving on.”
Marathon Valley is so-called as when the rover rolls into the area, it will have completed the distance of a marathon on Mars — 26 miles and 385 yards, or 42.195 kilometers. At its current location, Opportunity is a mere 128 meters from completing that distance.
Apart from being a momentous location for Opportunity’s epic 11 year-long exploration of the red planet, the valley also contains clay minerals as discerned from satellite spectroscopic data; clays that contain invaluable insights to Mars’ wet past. But it seems that the entrance to Marathon Valley is just as enticing as the valley itself promises.
One of the strange-looking blocks has been nicknamed “Jean-Baptiste Charbonneau” and, using its robotic arm-mounted Alpha Particle X-ray Spectrometer instrument, the rover has determined that the rock contains “relatively high concentrations of aluminum and silicon,” unlike any other rock sample analyzed by Opportunity or sister rover Spirit (that was sadly lost in 2010 after becoming stuck in a sand trap in Gusev Crater).
Opportunity’s science team has now selected another rock in the area, named “Sergeant Charles Floyd,” for additional analysis. The naming convention for these two rocks were inspired by the Lewis and Clark Expedition that ventured across Western portion of what is now the United States in the early 19th Century.
According to a NASA JPL news release, the rocks are gray, but the visible light spectrum of Charbonneau is more purple than most Mars rocks, whereas Floyd is more blue. The bluer rocks appear to lie higher on the ridge.
After analyzing Charbonneau, Opportunity’s mission team uploaded new software to the rover’s computer that is now instructing the rover to avoid writing data to a corrupt bank in the rover’s flash memory. It is now only writing data to 6 of the 7 banks in the hope that Opportunity’s “amnesia events” can be remedied.
Since late 2014, Opportunity has been in “no flash mode”, instead only using its volatile memory that is wiped every day. Lack of flash memory and frustrating rover resets have slowed progress in recent months, but with this new upgrade, mission engineers hope that Opportunity can shrug off these age-related issues and soldier on.
Read more at Discovery News
Mar 6, 2015
ISIS Militants 'Bulldoze' Ancient City in Iraq
The United Nations condemned as a "war crime" Friday the Islamic State group's bulldozing of the ancient city of Nimrud, the jihadists' latest demolition of Iraqi cultural treasures.
After rampaging through Mosul's museum with sledgehammers and torching its library last month, ISIS "bulldozed" the nearby ruins of Nimrud Thursday, the tourism and antiquities ministry said.
Antiquities officials said ISIS militants had moved trucks last week to the site, which overlooks the Tigris River, 30 kilometers (18 miles) southeast of their main hub of Mosul.
"Until now, we do not know to what extent it was destroyed," one official said.
Nimrud was the latest victim of what appears to be a systematic campaign by the jihadists to obliterate Iraq's rich heritage.
"I'm really devastated. But it was just a matter of time, now we're waiting for the video. It's sad," Abdulamir Hamdani, an Iraqi archaeologist from Stony Brook University in New York said of the propaganda film of the destruction that ISIS will likely release.
He said the site's guards were denied access to Nimrud, which was founded in the 13th century BC and was once considered the jewel of the Assyrian era.
Its stunning reliefs and colossal statues of winged bulls with human heads guarding palace gates filled the world's museums in the 19th century.
A collection of 613 pieces of gold jewelry, ornaments and precious stones discovered in a royal tomb in 1988 has been described as one of the greatest archaeological finds of the 20th century.
"Their plan is to destroy Iraqi heritage, one site at a time," said Hamdani.
"Hatra of course will be next," he added, referring to a 2,000-year-old UNESCO-listed site about 100 kilometers south of Mosul known for its beautifully preserved temples blending Hellenistic, Roman and Eastern influences.
Irina Bokova, the head of the UN's cultural body UNESCO, condemned the destruction of Nimrud "with the strongest force".
"We cannot stay silent. The deliberate destruction of cultural heritage constitutes a war crime, and I call on all political and religious leaders in the region to stand up against this new barbarity," she said Friday.
- 'Killing civilization' -
UNESCO has called for tougher action to protect the many heritage sites in one of the cradles of civilization but little can be done in areas under jihadist control.
The destruction was met with condemnation and sadness on Baghdad's Mutanabi Street, a favorite haunt of Iraqi intellectuals.
"After they killed the human spirit, they began killing civilization," Ibrahim Dawood, a writer and poet, said of IS.
"A civilization considered the pride of Iraq and the world was erased in minutes," said Adel Abdullah, a health ministry employee.
ISIS attempts to justify the destruction by saying the statues are idolatrous, but experts say the jihadists traffic antiquities to fund their self-proclaimed "caliphate" and only destroy the pieces that are too bulky to be smuggled.
Stuart Gibson, a UNESCO expert on museums, said pressure from the international community would have little effect on IS.
"We have also traditionally called upon the peoples of the region to recognize the irreplaceable value and cultural necessity in protecting their cultural heritage," he said.
"Unfortunately today the people in the region are exhausted and terrified. The remainder of us can only stand on the outside looking on in absolute despair."
ISIS still controls large parts of northern and western Iraq, but has been losing ground under mounting military pressure from Iraqi federal and Kurdish forces backed by a US-led coalition and by Iran.
Baghdad launched a huge offensive Monday to retake the city of Tikrit, in what commanders have said was a stepping stone toward an even larger operation to free Mosul.
Read more at Discovery News
After rampaging through Mosul's museum with sledgehammers and torching its library last month, ISIS "bulldozed" the nearby ruins of Nimrud Thursday, the tourism and antiquities ministry said.
Antiquities officials said ISIS militants had moved trucks last week to the site, which overlooks the Tigris River, 30 kilometers (18 miles) southeast of their main hub of Mosul.
"Until now, we do not know to what extent it was destroyed," one official said.
Nimrud was the latest victim of what appears to be a systematic campaign by the jihadists to obliterate Iraq's rich heritage.
"I'm really devastated. But it was just a matter of time, now we're waiting for the video. It's sad," Abdulamir Hamdani, an Iraqi archaeologist from Stony Brook University in New York said of the propaganda film of the destruction that ISIS will likely release.
He said the site's guards were denied access to Nimrud, which was founded in the 13th century BC and was once considered the jewel of the Assyrian era.
Its stunning reliefs and colossal statues of winged bulls with human heads guarding palace gates filled the world's museums in the 19th century.
A collection of 613 pieces of gold jewelry, ornaments and precious stones discovered in a royal tomb in 1988 has been described as one of the greatest archaeological finds of the 20th century.
"Their plan is to destroy Iraqi heritage, one site at a time," said Hamdani.
"Hatra of course will be next," he added, referring to a 2,000-year-old UNESCO-listed site about 100 kilometers south of Mosul known for its beautifully preserved temples blending Hellenistic, Roman and Eastern influences.
Irina Bokova, the head of the UN's cultural body UNESCO, condemned the destruction of Nimrud "with the strongest force".
"We cannot stay silent. The deliberate destruction of cultural heritage constitutes a war crime, and I call on all political and religious leaders in the region to stand up against this new barbarity," she said Friday.
- 'Killing civilization' -
UNESCO has called for tougher action to protect the many heritage sites in one of the cradles of civilization but little can be done in areas under jihadist control.
The destruction was met with condemnation and sadness on Baghdad's Mutanabi Street, a favorite haunt of Iraqi intellectuals.
"After they killed the human spirit, they began killing civilization," Ibrahim Dawood, a writer and poet, said of IS.
"A civilization considered the pride of Iraq and the world was erased in minutes," said Adel Abdullah, a health ministry employee.
ISIS attempts to justify the destruction by saying the statues are idolatrous, but experts say the jihadists traffic antiquities to fund their self-proclaimed "caliphate" and only destroy the pieces that are too bulky to be smuggled.
Stuart Gibson, a UNESCO expert on museums, said pressure from the international community would have little effect on IS.
"We have also traditionally called upon the peoples of the region to recognize the irreplaceable value and cultural necessity in protecting their cultural heritage," he said.
"Unfortunately today the people in the region are exhausted and terrified. The remainder of us can only stand on the outside looking on in absolute despair."
ISIS still controls large parts of northern and western Iraq, but has been losing ground under mounting military pressure from Iraqi federal and Kurdish forces backed by a US-led coalition and by Iran.
Baghdad launched a huge offensive Monday to retake the city of Tikrit, in what commanders have said was a stepping stone toward an even larger operation to free Mosul.
Read more at Discovery News
New Recipe For 19th Century Shipwrecked Beer
Scientists have scrutinized the contents of four bottles of beer found in a Baltic Sea shipwreck from the 1840s, an amber ale that perhaps was brewed in Belgium and was on its way to ports in Russia or Scandinavia.
The new analysis found that bacteria inside the beer bottles survived 170 years until it was discovered by divers in 2010, according to Brian Gibson, senior scientist at the VTT Technical Research Centre in Espoo, Finland.
“These bacteria were still alive,” Gibson said. The analysis “gave us some insight into the way that beers were brewed. We have a reasonably good idea about what kind of hops were used, different ones than today. These hops would have been harsher, these days they are quite mild. The one surprising thing is the beers were quite mild. The original alcohol level was 4.5 percent, nothing extreme.”
Gibson and colleagues at the University of Munich published their chemical and microbiological analysis recently in the Journal of Agriculture and Food Chemistry.
While some breweries have recreated ancient beer recipes from colonial, medieval or even Egyptian eras, Gibson believes this is the oldest intact bottle of beer. Over time, seawater seeped through the cork and made the contents about 30 percent saltwater. As a result, the big tasting by beer experts in Finland was a bit of a bust.
“The beer was quite degraded, it had a sell by date and it appeared to be well past that,” he said. “For the analysis, it was difficult to pick out the original flavors. We invited some of the most experienced beer tasters in Finland. The flavors were from bacterial contamination and not the original flavors of the beer.”
The scientists turned to chemical analysis of the remaining sugars and alcohol compounds.
“We looked at esters, which give beer a fruity or flowery taste. Most of the compounds that we would expect were there. In terms of the fruitiness, probably similar to modern beers. High level of 2-phenyl ethanol which gives a rose or floral aroma.”
Compared to modern craft brews, Gibson said it was like an amber or lambic ale, modern styles that are brewed with wild hops, floral and have sour notes.
Sam Calagione, founder and president of Dogfish Head brewery in Milton, Del., had been brewing historic beers since 1998, using recipes from archaeological digs that are passed on by scientists.
Dogfish’s “Midas Touch,” which is brewed from evidence found in a 2,700-year-old tomb in Turkey, is comprised of barley, saffron and white muscat grapes.
Read more at Discovery News
The new analysis found that bacteria inside the beer bottles survived 170 years until it was discovered by divers in 2010, according to Brian Gibson, senior scientist at the VTT Technical Research Centre in Espoo, Finland.
“These bacteria were still alive,” Gibson said. The analysis “gave us some insight into the way that beers were brewed. We have a reasonably good idea about what kind of hops were used, different ones than today. These hops would have been harsher, these days they are quite mild. The one surprising thing is the beers were quite mild. The original alcohol level was 4.5 percent, nothing extreme.”
Gibson and colleagues at the University of Munich published their chemical and microbiological analysis recently in the Journal of Agriculture and Food Chemistry.
While some breweries have recreated ancient beer recipes from colonial, medieval or even Egyptian eras, Gibson believes this is the oldest intact bottle of beer. Over time, seawater seeped through the cork and made the contents about 30 percent saltwater. As a result, the big tasting by beer experts in Finland was a bit of a bust.
“The beer was quite degraded, it had a sell by date and it appeared to be well past that,” he said. “For the analysis, it was difficult to pick out the original flavors. We invited some of the most experienced beer tasters in Finland. The flavors were from bacterial contamination and not the original flavors of the beer.”
The scientists turned to chemical analysis of the remaining sugars and alcohol compounds.
“We looked at esters, which give beer a fruity or flowery taste. Most of the compounds that we would expect were there. In terms of the fruitiness, probably similar to modern beers. High level of 2-phenyl ethanol which gives a rose or floral aroma.”
Compared to modern craft brews, Gibson said it was like an amber or lambic ale, modern styles that are brewed with wild hops, floral and have sour notes.
Sam Calagione, founder and president of Dogfish Head brewery in Milton, Del., had been brewing historic beers since 1998, using recipes from archaeological digs that are passed on by scientists.
Dogfish’s “Midas Touch,” which is brewed from evidence found in a 2,700-year-old tomb in Turkey, is comprised of barley, saffron and white muscat grapes.
Read more at Discovery News
Probe Enters Orbit Around Dwarf Planet Ceres
The year of the dwarf planet has begun.
NASA's Dawn probe arrived at Ceres today (March 6) at about 7:39 a.m. EST (1239 GMT), becoming the first spacecraft ever to orbit a dwarf planet. Dawn's observations over the next 16 months should lift the veil on Ceres, which has remained largely mysterious since its 1801 discovery, mission team members say.
"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," Dawn mission director and chief engineer Marc Rayman, who's based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home."
NASA officials got a signal from Dawn confirming that it's healthy and in orbit at about 8:36 a.m. EST (1336 GMT) today.
The milestone comes just four months ahead of another highly anticipated dwarf-planet encounter: On July 14, NASA's New Horizons probe will zoom through the Pluto system, giving scientists their first good looks at that faraway dwarf planet and its five known moons.
Dawn of the solar system
The $473 million Dawn mission launched in September 2007 to study Vesta and Ceres, the two largest objects in the main asteroid belt between Mars and Jupiter. Vesta's diameter is 330 miles (530 kilometers), while Ceres is about 590 miles (950 km) wide.
Both Vesta and Ceres are leftovers from the solar system's early days, planetary building blocks that would likely have kept growing if not for the interfering influence of Jupiter's immense gravitational tug.
The two bodies are "intact protoplanets from the very dawn of the solar system," Dawn Deputy Principal Investigator Carol Raymond, also of JPL, said during a news conference Monday (March 2)." So they're literally fossils that we can investigate to really understand the processes that were going on at that time."
Dawn orbited Vesta from July 2011 through September 2012, when the probe departed for Ceres. So today's arrival made history in another way as well: Dawn became the first spacecraft ever to orbit two objects beyond the Earth-moon system.
The mission's spaceflight feats are made possible by Dawn's innovative propulsion system, which accelerates xenon ions out the back of the spacecraft. This process generates tiny amounts of thrust; it would take Dawn four days to go from 0 to 60 mph (97 km/h), team members have said.
But Dawn's ion drive is about 10 times more efficient than traditional chemical systems. So the engines can keep firing for weeks, months and years, accelerating Dawn to tremendous speeds.
"With the 1,000 lbs. of xenon propellant that was loaded on board, Dawn has already accomplished more than 24,000 mph of velocity change," Dawn project manager Robert Mase of JPL said during Monday's news conference. "To put that in context: That's more than it takes to get a vehicle from the surface of the Earth up to the International Space Station."
Thanks to ion propulsion, Dawn crept up on Ceres slowly and gradually. The probe eased into orbit today without the need for any harrowing make-or-break maneuvers.
The mysteries of Ceres
Ceres is an intriguing world that in many ways looks more like the icy moons of the outer solar system, such as Jupiter's satellite Europa and the Saturn moon Enceladus, than its rocky neighbors in the asteroid belt.
For example, the dwarf planet is thought to consist of 25 to 30 percent water by mass, mostly in the form of ice. Ceres may also once have had (and might even still possess) an ocean of liquid water beneath its surface, as Europa and Enceladus do. Indeed, some researchers think Ceres may be capable of supporting microbial life.
"It's really going to be exciting to see what this exotic, alien world looks like," Rayman told Space.com in late January. "We're finally going to learn about this place."
Dawn is not equipped to search for signs of life. But the probe might be able to spot evidence of an underground ocean (if it exists), if it burbles up in places to interact with surface rocks, Rayman said. Measurements of Ceres' surface temperatures, when coupled with models of heat transportation through Ceres, could also shed light on the question of underground liquid water, said Dawn principal investigator Chris Russell of UCLA.
Dawn will also investigate two Ceres mysteries that have cropped up in the past year or so. Mission scientists will try to figure out just what is producing Ceres' mysterious bright spots, and they'll attempt to confirm and characterize a tenuous water-vapor plume spotted recently by researchers using Europe's Herschel Space Observatory.
Overall, Dawn will characterize the dwarf planet in detail, mapping out its surface and determining what Ceres is made of.
"We'll do typical planetary geology, more similar to what we do on Mars than what we did with Vesta," Russell told Space.com.
This work will not start immediately; Dawn will spend the next six weeks spiraling down to its initial science orbit, getting there on April 23. The probe will then begin taking Ceres' measure from an altitude of 8,400 miles (13,500 km). Dawn will study the dwarf planet from a series of increasingly closer-in orbits until the mission ends in June 2016.
Sizing up dwarf planets
While Ceres and Pluto are both dwarf planets — a category created by the International Astronomical Union (IAU) in 2006, when it demoted Pluto from a full-fledged planet in a decision that remains controversial today — they're quite different from each other, Russell said.
"Pluto formed differently, formed at a different time and formed out of different materials" than Ceres, he said.
Read more at Discovery News
NASA's Dawn probe arrived at Ceres today (March 6) at about 7:39 a.m. EST (1239 GMT), becoming the first spacecraft ever to orbit a dwarf planet. Dawn's observations over the next 16 months should lift the veil on Ceres, which has remained largely mysterious since its 1801 discovery, mission team members say.
"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," Dawn mission director and chief engineer Marc Rayman, who's based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home."
NASA officials got a signal from Dawn confirming that it's healthy and in orbit at about 8:36 a.m. EST (1336 GMT) today.
The milestone comes just four months ahead of another highly anticipated dwarf-planet encounter: On July 14, NASA's New Horizons probe will zoom through the Pluto system, giving scientists their first good looks at that faraway dwarf planet and its five known moons.
Dawn of the solar system
The $473 million Dawn mission launched in September 2007 to study Vesta and Ceres, the two largest objects in the main asteroid belt between Mars and Jupiter. Vesta's diameter is 330 miles (530 kilometers), while Ceres is about 590 miles (950 km) wide.
Both Vesta and Ceres are leftovers from the solar system's early days, planetary building blocks that would likely have kept growing if not for the interfering influence of Jupiter's immense gravitational tug.
The two bodies are "intact protoplanets from the very dawn of the solar system," Dawn Deputy Principal Investigator Carol Raymond, also of JPL, said during a news conference Monday (March 2)." So they're literally fossils that we can investigate to really understand the processes that were going on at that time."
Dawn orbited Vesta from July 2011 through September 2012, when the probe departed for Ceres. So today's arrival made history in another way as well: Dawn became the first spacecraft ever to orbit two objects beyond the Earth-moon system.
The mission's spaceflight feats are made possible by Dawn's innovative propulsion system, which accelerates xenon ions out the back of the spacecraft. This process generates tiny amounts of thrust; it would take Dawn four days to go from 0 to 60 mph (97 km/h), team members have said.
But Dawn's ion drive is about 10 times more efficient than traditional chemical systems. So the engines can keep firing for weeks, months and years, accelerating Dawn to tremendous speeds.
"With the 1,000 lbs. of xenon propellant that was loaded on board, Dawn has already accomplished more than 24,000 mph of velocity change," Dawn project manager Robert Mase of JPL said during Monday's news conference. "To put that in context: That's more than it takes to get a vehicle from the surface of the Earth up to the International Space Station."
Thanks to ion propulsion, Dawn crept up on Ceres slowly and gradually. The probe eased into orbit today without the need for any harrowing make-or-break maneuvers.
The mysteries of Ceres
Ceres is an intriguing world that in many ways looks more like the icy moons of the outer solar system, such as Jupiter's satellite Europa and the Saturn moon Enceladus, than its rocky neighbors in the asteroid belt.
For example, the dwarf planet is thought to consist of 25 to 30 percent water by mass, mostly in the form of ice. Ceres may also once have had (and might even still possess) an ocean of liquid water beneath its surface, as Europa and Enceladus do. Indeed, some researchers think Ceres may be capable of supporting microbial life.
"It's really going to be exciting to see what this exotic, alien world looks like," Rayman told Space.com in late January. "We're finally going to learn about this place."
Dawn is not equipped to search for signs of life. But the probe might be able to spot evidence of an underground ocean (if it exists), if it burbles up in places to interact with surface rocks, Rayman said. Measurements of Ceres' surface temperatures, when coupled with models of heat transportation through Ceres, could also shed light on the question of underground liquid water, said Dawn principal investigator Chris Russell of UCLA.
Dawn will also investigate two Ceres mysteries that have cropped up in the past year or so. Mission scientists will try to figure out just what is producing Ceres' mysterious bright spots, and they'll attempt to confirm and characterize a tenuous water-vapor plume spotted recently by researchers using Europe's Herschel Space Observatory.
Overall, Dawn will characterize the dwarf planet in detail, mapping out its surface and determining what Ceres is made of.
"We'll do typical planetary geology, more similar to what we do on Mars than what we did with Vesta," Russell told Space.com.
This work will not start immediately; Dawn will spend the next six weeks spiraling down to its initial science orbit, getting there on April 23. The probe will then begin taking Ceres' measure from an altitude of 8,400 miles (13,500 km). Dawn will study the dwarf planet from a series of increasingly closer-in orbits until the mission ends in June 2016.
Sizing up dwarf planets
While Ceres and Pluto are both dwarf planets — a category created by the International Astronomical Union (IAU) in 2006, when it demoted Pluto from a full-fledged planet in a decision that remains controversial today — they're quite different from each other, Russell said.
"Pluto formed differently, formed at a different time and formed out of different materials" than Ceres, he said.
Read more at Discovery News
Ancient 'Blue' Mars Lost an Entire Ocean to Space
Mars was once a small, wet and blue world, but over the past 4 billion years, Mars dried up and became the red dust bowl we know today.
But how much water did Mars possess? According to research published in the journal Science, the Martian northern hemisphere was likely covered in an ocean, covering a region of the approximate area as Earth’s Atlantic Ocean, plunging, in some places, to 1.6 kilometers (1 mile) deep.
“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space,” said Geronimo Villanueva, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the new paper, in an ESO news release. “With this work, we can better understand the history of water on Mars.”
Over a 6-year period, Villanueva and his team used the ESO’s Very Large Telescope (in Chile) and instruments at the W. M. Keck Observatory and the NASA Infrared Telescope Facility (both on Mauna Kea in Hawaii) to study the distribution of water molecules in the Martian atmosphere. By building a comprehensive map of water distribution and seasonal changes, they were able to arrive at this startling conclusion.
It is becoming clear that, over the aeons, Mars lost the majority of its atmosphere to space. That also goes for its water. Though large quantities of water were likely frozen below the surface as the atmosphere thinned and cooled, the water contained in an ocean of this size must have gone elsewhere — it must have also been lost to space.
The water in Earth’s oceans contains molecules of H2O, the familiar oxygen atom bound with 2 hydrogen atoms, and, in smaller quantities, the not-so-familiar HDO molecule. HDO is a type of water molecule that contains 1 hydrogen atom, 1 oxygen atom and 1 deuterium atom. The deuterium atom is an isotope of hydrogen; whereas hydrogen consists of 1 proton and an electron, deuterium consists of 1 proton, 1 neutron and 1 electron. Therefore, due to the extra neutron the deuterium contains, HDO molecules are slightly heavier than the regular H2O molecules.
Also known as “semi-heavy water,” HDO is less susceptible to being evaporated away and being lost to space, so logic dictates that if water is boiled (or sublimated) away on Mars, the H2O molecules will be preferentially lost to space whereas a higher proportion of HDO will be left behind.
By using powerful ground-based observatories, the researchers were able to determine the distribution of HDO molecules and the H2O molecules and compare their ratios to liquid water that is found in its natural state.
Of particular interest is Mars’ north and south poles where icecaps containing water and carbon dioxide ice persist to modern times. The water those icecaps contain is thought to document the evolution of water since the red planet’s wet Noachian period (approximately 3.7 billion years ago) to today. It turns out that the water measured in these polar regions is enriched with HDO by a factor of 7 when compared with water in Earth’s oceans. This, according to the study, indicates that Mars has lost a volume of water 6.5 times larger than the water currently contained within the modern-day icecaps.
Therefore, the volume of Mars’ early ocean must have been at least 20 million cubic kilometers, writes the news release.
Taking into account the Martian global terrain, most of the water would have been concentrated around the northern plains, a region dominated by low-lying land. An ancient ocean, with this estimate volume of water, would have covered 19 percent of the Martian globe, a significant area considering the Atlantic Ocean covers 17 percent of the Earth’s surface.
Read more at Discovery News
But how much water did Mars possess? According to research published in the journal Science, the Martian northern hemisphere was likely covered in an ocean, covering a region of the approximate area as Earth’s Atlantic Ocean, plunging, in some places, to 1.6 kilometers (1 mile) deep.
“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space,” said Geronimo Villanueva, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the new paper, in an ESO news release. “With this work, we can better understand the history of water on Mars.”
Over a 6-year period, Villanueva and his team used the ESO’s Very Large Telescope (in Chile) and instruments at the W. M. Keck Observatory and the NASA Infrared Telescope Facility (both on Mauna Kea in Hawaii) to study the distribution of water molecules in the Martian atmosphere. By building a comprehensive map of water distribution and seasonal changes, they were able to arrive at this startling conclusion.
It is becoming clear that, over the aeons, Mars lost the majority of its atmosphere to space. That also goes for its water. Though large quantities of water were likely frozen below the surface as the atmosphere thinned and cooled, the water contained in an ocean of this size must have gone elsewhere — it must have also been lost to space.
The water in Earth’s oceans contains molecules of H2O, the familiar oxygen atom bound with 2 hydrogen atoms, and, in smaller quantities, the not-so-familiar HDO molecule. HDO is a type of water molecule that contains 1 hydrogen atom, 1 oxygen atom and 1 deuterium atom. The deuterium atom is an isotope of hydrogen; whereas hydrogen consists of 1 proton and an electron, deuterium consists of 1 proton, 1 neutron and 1 electron. Therefore, due to the extra neutron the deuterium contains, HDO molecules are slightly heavier than the regular H2O molecules.
Also known as “semi-heavy water,” HDO is less susceptible to being evaporated away and being lost to space, so logic dictates that if water is boiled (or sublimated) away on Mars, the H2O molecules will be preferentially lost to space whereas a higher proportion of HDO will be left behind.
By using powerful ground-based observatories, the researchers were able to determine the distribution of HDO molecules and the H2O molecules and compare their ratios to liquid water that is found in its natural state.
Of particular interest is Mars’ north and south poles where icecaps containing water and carbon dioxide ice persist to modern times. The water those icecaps contain is thought to document the evolution of water since the red planet’s wet Noachian period (approximately 3.7 billion years ago) to today. It turns out that the water measured in these polar regions is enriched with HDO by a factor of 7 when compared with water in Earth’s oceans. This, according to the study, indicates that Mars has lost a volume of water 6.5 times larger than the water currently contained within the modern-day icecaps.
Therefore, the volume of Mars’ early ocean must have been at least 20 million cubic kilometers, writes the news release.
Taking into account the Martian global terrain, most of the water would have been concentrated around the northern plains, a region dominated by low-lying land. An ancient ocean, with this estimate volume of water, would have covered 19 percent of the Martian globe, a significant area considering the Atlantic Ocean covers 17 percent of the Earth’s surface.
Read more at Discovery News
Mar 5, 2015
Impressive Tomb of Celtic Prince Found in France
An Iron Age Celtic prince lay buried with his chariot at the center of a huge mound in the Champagne region of France, according to the country’s National Archaeological Research Institute (Inrap).
Standing near the small village of Lavau, in northwestern France, the mound, 130 feet across, has been dated to the 5th century BC. The 2,500-year-old tomb has at its center a 150-square-foot burial chamber, housing the deceased and his chariot.
“This exceptional tomb contains unique funerary artifacts, which are fitting for one of the highest elite of the end of the first Iron Age,” Inrap, who has been excavating the site since October last year, said in a statement.
The major find so far has been a large bronze-decorated wine cauldron, most likely made by Greek or Etruscan craftsmen.
The cauldron measures about 3.2 feet in diameter and has four circular handles which are decorated with bronze heads that depict the Greek god Acheloos. The river deity is represented horned, bearded, with ears of a bull and a triple mustache.
More decorations are found around the edge of the cauldron. These include eight lioness heads.
Inside the cauldron, the archaeologists found a ceramic wine vessel, called oniochoe, decorated with black figures. Decorations include the god Dionysus, lying under a vine and facing a woman.
“It’s likely a banqueting scene, which is a recurring theme in Greek iconography,” Inrap said.
The Greco-Latin wine set, the northernmost found so far, is typical of an aristocratic Celtic banquet.
The wine cauldron not only represents the deceased’s wealth and power — it also reflects the growing interaction between the Celtic elites and the Mediterranean world, Inrap said.
Read more at Discovery News
Standing near the small village of Lavau, in northwestern France, the mound, 130 feet across, has been dated to the 5th century BC. The 2,500-year-old tomb has at its center a 150-square-foot burial chamber, housing the deceased and his chariot.
“This exceptional tomb contains unique funerary artifacts, which are fitting for one of the highest elite of the end of the first Iron Age,” Inrap, who has been excavating the site since October last year, said in a statement.
The major find so far has been a large bronze-decorated wine cauldron, most likely made by Greek or Etruscan craftsmen.
The cauldron measures about 3.2 feet in diameter and has four circular handles which are decorated with bronze heads that depict the Greek god Acheloos. The river deity is represented horned, bearded, with ears of a bull and a triple mustache.
More decorations are found around the edge of the cauldron. These include eight lioness heads.
Inside the cauldron, the archaeologists found a ceramic wine vessel, called oniochoe, decorated with black figures. Decorations include the god Dionysus, lying under a vine and facing a woman.
“It’s likely a banqueting scene, which is a recurring theme in Greek iconography,” Inrap said.
The Greco-Latin wine set, the northernmost found so far, is typical of an aristocratic Celtic banquet.
The wine cauldron not only represents the deceased’s wealth and power — it also reflects the growing interaction between the Celtic elites and the Mediterranean world, Inrap said.
Read more at Discovery News
Jimmy Kimmel Taps Docs to Mock Anti-Vaccine Deniers
Late-night talk shows are better known for topical comedy and celebrities plugging their new movie or CD than they are for science education.
However, talk show host Jimmy Kimmel of ABC’s “Jimmy Kimmel Live” recently gave the pro-science, pro-vaccination effort a boost with a segment titled “A Message for the Anti-Vaccination Movement,” in which he mocked parents who refuse to get their kids vaccinated (“Here in L.A. parents are more scared of gluten than they are of smallpox,” Kimmel noted) followed by a funny and poignant video segment featuring real doctors addressing the anti-vaccination claims and expressing their (often bleeped and surely sincere) exasperation with those who refuse to vaccinate their children despite overwhelming scientific consensus about their safety.
Kimmel’s shout-out to medical science on the subject of vaccines is important and especially timely given the recent news story about measles outbreaks in Disneyland caused by unvaccinated children. Last month, the Toronto Star, one of Canada’s most prestigious newspapers, published an article highlighting the dangers of the Gardasil anti-HPV vaccine.
The article told the stories of a dozen Canadian girls whose health failed after receiving the vaccine and suggested that it was dangerous. The high-profile article suggested -- contrary to the bulk of scientific evidence -- that the vaccines were dangerous. Medical doctors and epidemiologists were outraged and the newspaper later acknowledged that they had “failed” in their reporting and did not give proper weight to science. The newspaper eventually retracted the story and removed it from its website.
Science Popularizers
This sort of high-profile star power can be very effective. Bringing science literacy to popular culture is nothing new, of course; Carl Sagan and Bill Nye have done it for decades. Astrophysicist and “Cosmos” host Neil deGrasse Tyson, for example, appeared on Comedy Central’s “The Colbert Report” in 2011 to explain how the ocean’s tides work, a phenomena that evidently completely baffled Bill O’Reilly on his Fox show “The O’Reilly Factor.” Though the tone was humorous Tyson took the opportunity to give a science-based, factual explanation of the process.
Even real-life doctors give flawed and misleading medical information; a study published in the “British Medical Journal” in December 2014 examining the medical advice given on TV talk shows such as "The Dr. Oz Show" and "The Doctors" concluded that many of the scientific claims made on the shows are unproven or unsubstantiated. In fact there was adequate evidence for fewer than half of the medical statements appearing on "The Dr. Oz Show."
In 2011, a viral video titled “I’m a Climate Scientist” from a group called Hungry Beast took a similar approach as Kimmel. Beginning by noting that the vast majority of people in the news media who discuss climate change are not scientists, the video (available in both clean and slightly NSFW versions) features nearly a dozen real-life climate scientists who sing a catchy hip hop song about the reality of climate change and clueless critics (sample lyric: “We’re scientists, what we speak is true… Unlike (climate change denier) Andrew Bolt our work is peer reviewed!”).
Jimmy Kimmel’s introduction notes, “If you’re one of these anti-vaccine people you probably aren’t going to take medical advice from a talk show host. I wouldn’t expect you to, I wouldn’t either. But I would expect you to take medical advice from almost every doctor in the world… The thing about doctors is that they didn’t learn about the human body from their friend’s Facebook page -- they went to medical school.”
Read more at Discovery News
However, talk show host Jimmy Kimmel of ABC’s “Jimmy Kimmel Live” recently gave the pro-science, pro-vaccination effort a boost with a segment titled “A Message for the Anti-Vaccination Movement,” in which he mocked parents who refuse to get their kids vaccinated (“Here in L.A. parents are more scared of gluten than they are of smallpox,” Kimmel noted) followed by a funny and poignant video segment featuring real doctors addressing the anti-vaccination claims and expressing their (often bleeped and surely sincere) exasperation with those who refuse to vaccinate their children despite overwhelming scientific consensus about their safety.
Kimmel’s shout-out to medical science on the subject of vaccines is important and especially timely given the recent news story about measles outbreaks in Disneyland caused by unvaccinated children. Last month, the Toronto Star, one of Canada’s most prestigious newspapers, published an article highlighting the dangers of the Gardasil anti-HPV vaccine.
The article told the stories of a dozen Canadian girls whose health failed after receiving the vaccine and suggested that it was dangerous. The high-profile article suggested -- contrary to the bulk of scientific evidence -- that the vaccines were dangerous. Medical doctors and epidemiologists were outraged and the newspaper later acknowledged that they had “failed” in their reporting and did not give proper weight to science. The newspaper eventually retracted the story and removed it from its website.
Science Popularizers
This sort of high-profile star power can be very effective. Bringing science literacy to popular culture is nothing new, of course; Carl Sagan and Bill Nye have done it for decades. Astrophysicist and “Cosmos” host Neil deGrasse Tyson, for example, appeared on Comedy Central’s “The Colbert Report” in 2011 to explain how the ocean’s tides work, a phenomena that evidently completely baffled Bill O’Reilly on his Fox show “The O’Reilly Factor.” Though the tone was humorous Tyson took the opportunity to give a science-based, factual explanation of the process.
Even real-life doctors give flawed and misleading medical information; a study published in the “British Medical Journal” in December 2014 examining the medical advice given on TV talk shows such as "The Dr. Oz Show" and "The Doctors" concluded that many of the scientific claims made on the shows are unproven or unsubstantiated. In fact there was adequate evidence for fewer than half of the medical statements appearing on "The Dr. Oz Show."
In 2011, a viral video titled “I’m a Climate Scientist” from a group called Hungry Beast took a similar approach as Kimmel. Beginning by noting that the vast majority of people in the news media who discuss climate change are not scientists, the video (available in both clean and slightly NSFW versions) features nearly a dozen real-life climate scientists who sing a catchy hip hop song about the reality of climate change and clueless critics (sample lyric: “We’re scientists, what we speak is true… Unlike (climate change denier) Andrew Bolt our work is peer reviewed!”).
Jimmy Kimmel’s introduction notes, “If you’re one of these anti-vaccine people you probably aren’t going to take medical advice from a talk show host. I wouldn’t expect you to, I wouldn’t either. But I would expect you to take medical advice from almost every doctor in the world… The thing about doctors is that they didn’t learn about the human body from their friend’s Facebook page -- they went to medical school.”
Read more at Discovery News
Fastest Star Ever Seen Will Escape from the Galaxy
The compact star US 708 hasn’t had an easy life. Paired with a domineering partner, 708’s mass was siphoned away, reducing it to a dense, helium-filled core.
But 708 didn’t go quietly into the night. Instead, scientists believe the feeding frenzy ended in a supernova explosion that catapulted the ravaged remains with such force it’s leaving the galaxy. Fast.
A new study shows that the star, classified as a hot subdwarf, is blasting through the Milky Way at about 750 miles per second, faster than any other star in the galaxy.
It's also the only one of about 20 similar runaways slingshot away by a supernova explosion, research published in this week’s Science shows.
The other stars traveling fast enough to leave the Milky Way’s gravitational fist are believed to have been booted by the supermassive black hole lurking in the center of the galaxy.
“US 708 does not come from the galactic center. We don't know any other supermassive black hole in our galaxy. One needs one of those. A smaller, stellar-mass black hole formed by the collapse of a massive star can't do the job,” astronomer Stephan Geier, with the European Southern Observatory, told Discovery News.
“It’s only one object so far,” he added, but if others can be found, scientists would have a way to directly study supernova.
US 708 will leave the Milky Way in roughly 25 million years, cooling over time and transforming into a white dwarf star.
Astronomers first found the star in 2005, but at that time could only determine the velocity, not the rapid spin, which later became evidence for its donor past.
In 2009, theorists developed computer models showing that stars could reach escape velocity by a supernova blasts.
“This motivated us to have a closer look at US 708 again,” Geier said.
Read more at Discovery News
But 708 didn’t go quietly into the night. Instead, scientists believe the feeding frenzy ended in a supernova explosion that catapulted the ravaged remains with such force it’s leaving the galaxy. Fast.
A new study shows that the star, classified as a hot subdwarf, is blasting through the Milky Way at about 750 miles per second, faster than any other star in the galaxy.
It's also the only one of about 20 similar runaways slingshot away by a supernova explosion, research published in this week’s Science shows.
The other stars traveling fast enough to leave the Milky Way’s gravitational fist are believed to have been booted by the supermassive black hole lurking in the center of the galaxy.
“US 708 does not come from the galactic center. We don't know any other supermassive black hole in our galaxy. One needs one of those. A smaller, stellar-mass black hole formed by the collapse of a massive star can't do the job,” astronomer Stephan Geier, with the European Southern Observatory, told Discovery News.
“It’s only one object so far,” he added, but if others can be found, scientists would have a way to directly study supernova.
US 708 will leave the Milky Way in roughly 25 million years, cooling over time and transforming into a white dwarf star.
Astronomers first found the star in 2005, but at that time could only determine the velocity, not the rapid spin, which later became evidence for its donor past.
In 2009, theorists developed computer models showing that stars could reach escape velocity by a supernova blasts.
“This motivated us to have a closer look at US 708 again,” Geier said.
Read more at Discovery News
Hubble Shows Mirror, Mirror, Mirror, Mirror of an Ancient Supernova
Researchers using the Hubble Space Telescope took advantage of a naturally occurring zoom lens in space to capture an unprecedented quadruple image of an ancient supernova.
Between the supernova and the Earth-orbiting Hubble observatory lies a massive galaxy cluster whose gravity bends the path of the traveling photons. The existence of so-called “gravitational lenses” was proposed 100 years ago by physicist Albert Einstein. The first cosmic lens was discovered in 1979.
“Einstein’s theory of general relativity says that massive objects bend space and time. Light traveling close to massive objects will have their paths’ bent,” said astronomer Jennifer Lotz, with the Space Telescope Science Institute in Baltimore.
In addition to testing Einstein’s theory of relativity, this type of curved light could be used to measure how fast the universe is expanding.
Astronomer Patrick Kelly, with the University of California Berkeley, and colleagues report this week about four different routes light from an ancient supernova took to reach the Hubble telescope after being deflected around an intervening elliptical galaxy. The phenomenon is known as an Einstein cross.
“Basically, we get to see the supernova four times and measure the time delays between its arrival in the different images, hopefully learning something about the supernova and the kind of star it exploded from, as well as about the gravitational lenses,” Kelly said in a statement.
The supernova will appear again in the next 10 years, as its light takes different paths around and through the gravitational lens.
The research is published in this week’s Science.
From Discovery News
Between the supernova and the Earth-orbiting Hubble observatory lies a massive galaxy cluster whose gravity bends the path of the traveling photons. The existence of so-called “gravitational lenses” was proposed 100 years ago by physicist Albert Einstein. The first cosmic lens was discovered in 1979.
“Einstein’s theory of general relativity says that massive objects bend space and time. Light traveling close to massive objects will have their paths’ bent,” said astronomer Jennifer Lotz, with the Space Telescope Science Institute in Baltimore.
In addition to testing Einstein’s theory of relativity, this type of curved light could be used to measure how fast the universe is expanding.
Astronomer Patrick Kelly, with the University of California Berkeley, and colleagues report this week about four different routes light from an ancient supernova took to reach the Hubble telescope after being deflected around an intervening elliptical galaxy. The phenomenon is known as an Einstein cross.
“Basically, we get to see the supernova four times and measure the time delays between its arrival in the different images, hopefully learning something about the supernova and the kind of star it exploded from, as well as about the gravitational lenses,” Kelly said in a statement.
The supernova will appear again in the next 10 years, as its light takes different paths around and through the gravitational lens.
The research is published in this week’s Science.
From Discovery News
The Higgs Boson May Disintegrate into Dark Matter
The hunt for the source of dark matter is one of the most hotly anticipated searches of our time and the Higgs boson might be able to light the way to a possible dark matter discovery.
Confirmation of a Higgs boson discovery came in 2012 after a multi-decade search. Theorized in the 1960′s, experiments at CERN’s Large Hadron Collider (LHC) near Geneva, Switzerland, decades later confirmed the particle’s decay signature, eventually leading to the 2013 Nobel Prize for Physics being awarded to Peter Higgs and François Englert, two of the key physicists who laid out the theoretical framework for the particle.
As we already know, the Higgs particle mediates the Higgs field, which endows all matter with mass. The discovery of the Higgs boson at the LHC was the last “missing piece” of the Standard Model of physics. The Standard Model governs our understanding of the quantum world; it’s a recipe book of sorts that enables us to understand how subatomic particles and forces interact on the smallest of scales.
However, though the basic framework of the Standard Model works for most of our purposes, it is not an all-encompassing model. Most notably, the Standard Model does not incorporate gravity — obviously a very important omission. Also, the Standard Model does not predict the source of mysterious dark matter — a fact that is growing more contentious by the day.
Cosmological studies predict that 84.5 percent of the universe is composed of matter that can exert a gravitational force and yet does not interact with the electromagnetic force. It is a type of matter — known as non-baryonic matter — that cannot be seen, but its effects become extremely obvious when observing the gravitational effects in galactic clusters, for example. It’s out there, we’re certain of it, but we just can’t see it and therefore cannot fully understand its nature.
There are many theories suggesting different exotic sources of dark matter, but a new model put forward by a team headed by theoretical particle physicist Christoffer Petersson, of Chalmers University of Technology in Sweden, will be tested at the LHC when it is restarted this spring.
Petersson suggests that the Higgs boson may decay in an alternative way than what has been observed to date; a decay path that is governed by supersymmetry.
Supersymmetry predicts that there are more massive “super partners” of known particles that exist beyond the Standard Model framework. Although there have been tantalizing hints of these supersymmetric particles, definitive observational evidence has been frustratingly hard to track down.
But in the LHC’s new phase of operations, where particle collisions will be boosted to record energies, evidence of supersymmetry may be more forthcoming. And this is where the Higgs comes in.
The LHC’s detectors didn’t directly ‘see’ a Higgs boson when it made its discovery. The ATLAS and CMS detectors, over countless billions of particle collisions, slowly built up a picture of post-collision particles that sprayed away from the energy generated after counter-rotating protons smashed into one another. From this collision energy, Higgs boson particles condensed in isolation but rapidly decayed into other particles that the detectors could measure, such as muons (the electron’s more massive cousin). This provided a Higgs ‘fingerprint’ of sorts, evidence that Higgs bosons are being generated.
Read more at Discovery News
Confirmation of a Higgs boson discovery came in 2012 after a multi-decade search. Theorized in the 1960′s, experiments at CERN’s Large Hadron Collider (LHC) near Geneva, Switzerland, decades later confirmed the particle’s decay signature, eventually leading to the 2013 Nobel Prize for Physics being awarded to Peter Higgs and François Englert, two of the key physicists who laid out the theoretical framework for the particle.
As we already know, the Higgs particle mediates the Higgs field, which endows all matter with mass. The discovery of the Higgs boson at the LHC was the last “missing piece” of the Standard Model of physics. The Standard Model governs our understanding of the quantum world; it’s a recipe book of sorts that enables us to understand how subatomic particles and forces interact on the smallest of scales.
However, though the basic framework of the Standard Model works for most of our purposes, it is not an all-encompassing model. Most notably, the Standard Model does not incorporate gravity — obviously a very important omission. Also, the Standard Model does not predict the source of mysterious dark matter — a fact that is growing more contentious by the day.
Cosmological studies predict that 84.5 percent of the universe is composed of matter that can exert a gravitational force and yet does not interact with the electromagnetic force. It is a type of matter — known as non-baryonic matter — that cannot be seen, but its effects become extremely obvious when observing the gravitational effects in galactic clusters, for example. It’s out there, we’re certain of it, but we just can’t see it and therefore cannot fully understand its nature.
There are many theories suggesting different exotic sources of dark matter, but a new model put forward by a team headed by theoretical particle physicist Christoffer Petersson, of Chalmers University of Technology in Sweden, will be tested at the LHC when it is restarted this spring.
Petersson suggests that the Higgs boson may decay in an alternative way than what has been observed to date; a decay path that is governed by supersymmetry.
Supersymmetry predicts that there are more massive “super partners” of known particles that exist beyond the Standard Model framework. Although there have been tantalizing hints of these supersymmetric particles, definitive observational evidence has been frustratingly hard to track down.
But in the LHC’s new phase of operations, where particle collisions will be boosted to record energies, evidence of supersymmetry may be more forthcoming. And this is where the Higgs comes in.
The LHC’s detectors didn’t directly ‘see’ a Higgs boson when it made its discovery. The ATLAS and CMS detectors, over countless billions of particle collisions, slowly built up a picture of post-collision particles that sprayed away from the energy generated after counter-rotating protons smashed into one another. From this collision energy, Higgs boson particles condensed in isolation but rapidly decayed into other particles that the detectors could measure, such as muons (the electron’s more massive cousin). This provided a Higgs ‘fingerprint’ of sorts, evidence that Higgs bosons are being generated.
Read more at Discovery News
Mar 4, 2015
Young Dino Weighed Whopping 3,527 Lbs
At least some young adult dinosaurs were enormous, suggests a new study that found a still-youthful Stegosaurus stenops weighed a scale-crushing 3,527 pounds when it died an untimely death.
The detailed method for estimating the dinosaur’s weight could not only reveal more about this particular dinosaur species, but it also could be used to more accurately estimate the weight of other dinosaurs.
In this case, the technique was used on the world’s most complete remains of the armored plant-eating stegosaur, whose skeleton is a star attraction at the Natural History Museum in London. It lived 150 million years ago.
“These findings identify just how important exceptionally complete specimens like this are for scientific research and collections,” Paul Barrett, lead dinosaur researcher at the museum, said in a press release.
He continued, “Now we know the weight, we can start to find out more about its metabolism, feeding requirements and the growth rates of Stegosaurus. We can also use the same techniques on other complete fossils to find out much more about the wider ecology of dinosaurs.”
Barrett, lead author Charlotte Brassey, and their team first fitted simple shapes to a digital recreation of the dinosaur’s skeleton before calculating volume.
The researchers next converted these results into a body mass using data collected from similar modern animals. They believe their results are as accurate as possible for now because, when compared to figures calculated using the alternative method of measuring leg bone circumference in conjunction with the overall weight of various living animals, the results are in close agreement.
Both techniques produced an estimate of 1600 kg (3,527 pounds) and, combined, are now considered the most accurate way of measuring the body weight from nearly complete fossil skeletons.
Read more at Discovery News
The detailed method for estimating the dinosaur’s weight could not only reveal more about this particular dinosaur species, but it also could be used to more accurately estimate the weight of other dinosaurs.
In this case, the technique was used on the world’s most complete remains of the armored plant-eating stegosaur, whose skeleton is a star attraction at the Natural History Museum in London. It lived 150 million years ago.
“These findings identify just how important exceptionally complete specimens like this are for scientific research and collections,” Paul Barrett, lead dinosaur researcher at the museum, said in a press release.
He continued, “Now we know the weight, we can start to find out more about its metabolism, feeding requirements and the growth rates of Stegosaurus. We can also use the same techniques on other complete fossils to find out much more about the wider ecology of dinosaurs.”
Barrett, lead author Charlotte Brassey, and their team first fitted simple shapes to a digital recreation of the dinosaur’s skeleton before calculating volume.
The researchers next converted these results into a body mass using data collected from similar modern animals. They believe their results are as accurate as possible for now because, when compared to figures calculated using the alternative method of measuring leg bone circumference in conjunction with the overall weight of various living animals, the results are in close agreement.
Both techniques produced an estimate of 1600 kg (3,527 pounds) and, combined, are now considered the most accurate way of measuring the body weight from nearly complete fossil skeletons.
Read more at Discovery News
Humans Emerged Much Earlier Than Thought
A digital makeover of the supposedly earliest known human, Homo habilis aka "Handy Man," finds that this species could not have been at the base of the human family tree, which moves the origins of our entire genus back tens of thousands of years.
When the 1.8-million-year-old remains of Handy Man were announced in 1964, it was thought that they belonged to the first ever human, but the new study, published in Nature, shows that cannot be true. A jaw for yet another early human dating to 2.3 million years ago turns out to be too modern to be ancestral to Handy Man.
"Our evidence suggests that earliest Homo must be well older than 2.3 million years old, because the Homo upper jaw of that age is already too evolved to fit with the primitive Homo habilis jaw," lead author Fred Spoor from the Max Planck Institute for Evolutionary Anthropology explained to Discovery News.
Using state-of the-art computer reconstruction techniques, Spoor and his team created a digital model of Handy Man's remains. Found in Olduvai Gorge, Tanzania, by famed anthropologist Louis Leakey and his colleagues, the fossils consist of a lower jaw, parts of a braincase and the hand bones of a single individual.
The new digital "makeover" reveals that Handy Man had a large brain, similar to that of the other early human species Homo erectus (Upright Man), but a lower jaw that was more like a much older species, Australopithecus afarensis, which is well represented by the "Lucy" set of fossils. Handy Man also had longer arms than today's humans, which was probably a trait passed down from our tree-swinging ancestors.
As for the 2.3-million-year-old upper jawbone, it was found in Ethiopia. Spoor and his team now think that Handy Man from Tanzania and this early Ethiopian individual represent separate evolutionary lineages that likely split well before 2.3 million years ago.
Now the question is, who was the ancestor of these two, and how long ago did this individual live? It could be that the very first human dates closer to 3 million years ago, the researchers suspect.
Yet another extraordinary possibility to consider is that Handy Man, Upright Man and another early human Homo rudolfensis might have overlapped in time and geographic location.
"Given that the three species differed in how their jaws and face were built, it seems reasonable to speculate that they occupied different ecological niches characterized by different diets," Spoor said.
Even so, they had one important feature in common that suggests how our genus evolved in the first place.
"As all three recognized species of early Homo share an equally enlarged brain compared with Australopithecus species, it can be inferred that their common ancestor at the beginning of the Homo lineage had an enlarged brain," Spoor said.
Bernard Wood, who has also studied early humans, is a professor at George Washington University and an honorary professor at the University of Kent. Wood told Discovery News that the new study is "one of the coolest papers (I've read) in a long time."
Read more at Discovery News
When the 1.8-million-year-old remains of Handy Man were announced in 1964, it was thought that they belonged to the first ever human, but the new study, published in Nature, shows that cannot be true. A jaw for yet another early human dating to 2.3 million years ago turns out to be too modern to be ancestral to Handy Man.
"Our evidence suggests that earliest Homo must be well older than 2.3 million years old, because the Homo upper jaw of that age is already too evolved to fit with the primitive Homo habilis jaw," lead author Fred Spoor from the Max Planck Institute for Evolutionary Anthropology explained to Discovery News.
Using state-of the-art computer reconstruction techniques, Spoor and his team created a digital model of Handy Man's remains. Found in Olduvai Gorge, Tanzania, by famed anthropologist Louis Leakey and his colleagues, the fossils consist of a lower jaw, parts of a braincase and the hand bones of a single individual.
The new digital "makeover" reveals that Handy Man had a large brain, similar to that of the other early human species Homo erectus (Upright Man), but a lower jaw that was more like a much older species, Australopithecus afarensis, which is well represented by the "Lucy" set of fossils. Handy Man also had longer arms than today's humans, which was probably a trait passed down from our tree-swinging ancestors.
As for the 2.3-million-year-old upper jawbone, it was found in Ethiopia. Spoor and his team now think that Handy Man from Tanzania and this early Ethiopian individual represent separate evolutionary lineages that likely split well before 2.3 million years ago.
Now the question is, who was the ancestor of these two, and how long ago did this individual live? It could be that the very first human dates closer to 3 million years ago, the researchers suspect.
Yet another extraordinary possibility to consider is that Handy Man, Upright Man and another early human Homo rudolfensis might have overlapped in time and geographic location.
"Given that the three species differed in how their jaws and face were built, it seems reasonable to speculate that they occupied different ecological niches characterized by different diets," Spoor said.
Even so, they had one important feature in common that suggests how our genus evolved in the first place.
"As all three recognized species of early Homo share an equally enlarged brain compared with Australopithecus species, it can be inferred that their common ancestor at the beginning of the Homo lineage had an enlarged brain," Spoor said.
Bernard Wood, who has also studied early humans, is a professor at George Washington University and an honorary professor at the University of Kent. Wood told Discovery News that the new study is "one of the coolest papers (I've read) in a long time."
Read more at Discovery News
First Known Human Found in Ethiopia
The first known human lived in Ethiopia 2.8 million years ago, according to two remarkable new studies that also reveal the conditions under which the earliest humans evolved.
Prior to this research, which is published in the journal Science, the earliest known member of our genus was dated to around 2.3-2.4 million years ago, so the new remains push back the history of humanity by approximately 400,000 years.
"Prior to 3 million years, humans were relatively ape-like and partially arboreal, partially bipedal," Brian Villmoare, who led the research on the fossil remains, told Discovery News. "They lived in the forest, had small brains, and did not eat meat or use tools."
"After 2 million years," he continued, "humans have large brains, stone tools, and eat meat, so this transitional period is very important in terms of human evolution."
The 2.8-million-year old remains consist of a fossil lower jaw and teeth. They were unearthed at the Ledi-Geraru research area at Afar Regional State, Ethiopia.
Villmoare, a researcher at the University of Nevada Las Vegas, and his colleagues do not name the individual's species, but it likely is the common ancestor of at least two separate human lineages that split at around 2.3 million years ago, with one remaining in Ethiopia and the other going to Tanzania.
Since only a jaw bone with teeth are all that's believed to be left of the first known human, the scientists cannot say much about what this individual's body looked like.
"But," Villmoare quickly added, "there does appear to have been a general reduction in skeletal and dental elements in this jaw, which is consistent with the transition to the Homo adaptive pattern."
As humans likely evolved from the more ape-like Australopithecus, represented by the famous "Lucy" remains, we started to lose features evolved for a past life in trees and to gain characteristics associated more with modern humans, such as shorter arms.
In a separate study led by Erin DiMaggio of Pennsylvania State University, the ecosystem where the first known human was found is described. Clearly, this individual had a lot of company.
"We found a large number of fossils of grazing animals, similar to modern wildebeests and zebras, which show that early Homo lived in an area of grasslands, similar to the modern Serengeti Plains in Tanzania, except that this habitat had rivers and lakes as we have fish, hippos, and crocodiles, as well as antelope that lived near grasses inundated with water," co-author Kaye Reed of the Institute of Human Origins and School of Human Evolution and Social Change, told Discovery News. "There were very few trees, however, except possibly a few near the water sources."
Reed added that she and her colleagues also recovered saber-toothed cats and hyenas, two types of warthogs and a very large baboon that is related to the modern gelada baboon seen today in the Ethiopian highlands.
The researchers suspect that the first known human was feasting on some of this meat, but also become prey.
"The saber-toothed cats, hyenas and other large carnivores could have preyed upon Homo," Reed said. "It was a dangerous place!"
Austrolopithecus and still earlier ape-like humans appear to have evolved in a more forested environment, so climate change could have caused "Lucy" and her kind to evolve features more suitable for a terrestrial lifestyle. Villmoare said that "humans evolved to adapt to a dryer environment," even though the habitat of the first known human included water sources.
Read more at Discovery News
Prior to this research, which is published in the journal Science, the earliest known member of our genus was dated to around 2.3-2.4 million years ago, so the new remains push back the history of humanity by approximately 400,000 years.
"Prior to 3 million years, humans were relatively ape-like and partially arboreal, partially bipedal," Brian Villmoare, who led the research on the fossil remains, told Discovery News. "They lived in the forest, had small brains, and did not eat meat or use tools."
"After 2 million years," he continued, "humans have large brains, stone tools, and eat meat, so this transitional period is very important in terms of human evolution."
The 2.8-million-year old remains consist of a fossil lower jaw and teeth. They were unearthed at the Ledi-Geraru research area at Afar Regional State, Ethiopia.
Villmoare, a researcher at the University of Nevada Las Vegas, and his colleagues do not name the individual's species, but it likely is the common ancestor of at least two separate human lineages that split at around 2.3 million years ago, with one remaining in Ethiopia and the other going to Tanzania.
Since only a jaw bone with teeth are all that's believed to be left of the first known human, the scientists cannot say much about what this individual's body looked like.
"But," Villmoare quickly added, "there does appear to have been a general reduction in skeletal and dental elements in this jaw, which is consistent with the transition to the Homo adaptive pattern."
As humans likely evolved from the more ape-like Australopithecus, represented by the famous "Lucy" remains, we started to lose features evolved for a past life in trees and to gain characteristics associated more with modern humans, such as shorter arms.
In a separate study led by Erin DiMaggio of Pennsylvania State University, the ecosystem where the first known human was found is described. Clearly, this individual had a lot of company.
"We found a large number of fossils of grazing animals, similar to modern wildebeests and zebras, which show that early Homo lived in an area of grasslands, similar to the modern Serengeti Plains in Tanzania, except that this habitat had rivers and lakes as we have fish, hippos, and crocodiles, as well as antelope that lived near grasses inundated with water," co-author Kaye Reed of the Institute of Human Origins and School of Human Evolution and Social Change, told Discovery News. "There were very few trees, however, except possibly a few near the water sources."
Reed added that she and her colleagues also recovered saber-toothed cats and hyenas, two types of warthogs and a very large baboon that is related to the modern gelada baboon seen today in the Ethiopian highlands.
The researchers suspect that the first known human was feasting on some of this meat, but also become prey.
"The saber-toothed cats, hyenas and other large carnivores could have preyed upon Homo," Reed said. "It was a dangerous place!"
Austrolopithecus and still earlier ape-like humans appear to have evolved in a more forested environment, so climate change could have caused "Lucy" and her kind to evolve features more suitable for a terrestrial lifestyle. Villmoare said that "humans evolved to adapt to a dryer environment," even though the habitat of the first known human included water sources.
Read more at Discovery News
Massive Exoplanet Evolved in Extreme 4-Star System
For only the second time, an exoplanet living with an expansive family of four stars has been revealed.
The exoplanet, which is a huge gaseous world 10 times the mass of Jupiter, was previously known to occupy a 3-star system, but a fourth star (a red dwarf) has now been found, revealing quadruple star systems possessing planets are more common than we thought.
“About four percent of solar-type stars are in quadruple systems, which is up from previous estimates because observational techniques are steadily improving,” said co-author Andrei Tokovinin of the Cerro Tololo Inter-American Observatory in Chile.
The whole 4-star family is collectively known as 30 Ari, located some 136 light-years from Earth — in our interstellar backyard. The exoplanet orbits the primary star of the system once every 335 days. The primary star has a new-found binary partner (which the exoplanet does not orbit) and this pair are locked in an orbital dance with a secondary binary, separated by a distance of 1,670 astronomical unit (AU), where 1 AU is the average distance between the Earth and sun.
The new star discovery was made by the Robo-AO adaptive optics system, developed by the Inter-University Center for Astronomy and Astrophysics in India and the California Institute of Technology (Caltech), and the PALM-3000 adaptive optics system, developed by NASA’s Jet Propulsion Laboratory in Pasadena, Calif., two instruments at the Palomar Observatory in San Diego, Calif.
The discovery of planets in systems like 30 Ari raises some important questions about planetary formation in multi-star systems and, as this particular system is so extreme, astronomers doubt that the massive exoplanet, nor its hypothetical system of moons, could support life (as we know it).
Although undoubtedly rare, this is the second exoplanet discovered in a quadruple star system. The first, KIC 4862625, was discovered by a citizen science project that scours data from the Kepler space telescope to seek out exoplanetary transit signals. But the fact that two such systems have been discovered, when only a couple of thousand exoplanets have been discovered so far, hints that exoplanet formation can occur in some pretty unlikely places.
“Star systems come in myriad forms. There can be single stars, binary stars, triple stars, even quintuple star systems,” said Lewis Roberts of JPL. “It’s amazing the way nature puts these things together.” Roberts is the lead author of the study to be published in the Astronomical Journal.
Most stars in our galaxy are known to exist in multi-star systems and astronomers are currently trying to understand how they came to be this way. Were the stars gravitationally bound at birth inside their stellar nurseries? Or did they capture one another some time in their travels around the Milky Way? Recent unrelated research hints that multi-star systems may be born that way.
Now, with the increasing number of exoplanet discoveries in binary and multi-star systems, we are quickly realizing that many of our science fiction notions of far-off alien worlds are now actually modern science fact. One such world is Luke Skywalker’s homeworld Tatooine from “Star Wars: A New Hope”, where, at sunset, two stars of a binary pair dip low on the horizon.
But how would this multi-star system look from the vantage point of the exoplanet in 30 Ari? According to a NASA JPL news release, “the four parent stars would look like one small sun and two very bright stars that would be visible in daylight. One of those stars, if viewed with a large enough telescope, would be revealed to be a binary system, or two stars orbiting each other.”
Read more at Discovery News
The exoplanet, which is a huge gaseous world 10 times the mass of Jupiter, was previously known to occupy a 3-star system, but a fourth star (a red dwarf) has now been found, revealing quadruple star systems possessing planets are more common than we thought.
“About four percent of solar-type stars are in quadruple systems, which is up from previous estimates because observational techniques are steadily improving,” said co-author Andrei Tokovinin of the Cerro Tololo Inter-American Observatory in Chile.
The whole 4-star family is collectively known as 30 Ari, located some 136 light-years from Earth — in our interstellar backyard. The exoplanet orbits the primary star of the system once every 335 days. The primary star has a new-found binary partner (which the exoplanet does not orbit) and this pair are locked in an orbital dance with a secondary binary, separated by a distance of 1,670 astronomical unit (AU), where 1 AU is the average distance between the Earth and sun.
The new star discovery was made by the Robo-AO adaptive optics system, developed by the Inter-University Center for Astronomy and Astrophysics in India and the California Institute of Technology (Caltech), and the PALM-3000 adaptive optics system, developed by NASA’s Jet Propulsion Laboratory in Pasadena, Calif., two instruments at the Palomar Observatory in San Diego, Calif.
The discovery of planets in systems like 30 Ari raises some important questions about planetary formation in multi-star systems and, as this particular system is so extreme, astronomers doubt that the massive exoplanet, nor its hypothetical system of moons, could support life (as we know it).
Although undoubtedly rare, this is the second exoplanet discovered in a quadruple star system. The first, KIC 4862625, was discovered by a citizen science project that scours data from the Kepler space telescope to seek out exoplanetary transit signals. But the fact that two such systems have been discovered, when only a couple of thousand exoplanets have been discovered so far, hints that exoplanet formation can occur in some pretty unlikely places.
“Star systems come in myriad forms. There can be single stars, binary stars, triple stars, even quintuple star systems,” said Lewis Roberts of JPL. “It’s amazing the way nature puts these things together.” Roberts is the lead author of the study to be published in the Astronomical Journal.
Most stars in our galaxy are known to exist in multi-star systems and astronomers are currently trying to understand how they came to be this way. Were the stars gravitationally bound at birth inside their stellar nurseries? Or did they capture one another some time in their travels around the Milky Way? Recent unrelated research hints that multi-star systems may be born that way.
Now, with the increasing number of exoplanet discoveries in binary and multi-star systems, we are quickly realizing that many of our science fiction notions of far-off alien worlds are now actually modern science fact. One such world is Luke Skywalker’s homeworld Tatooine from “Star Wars: A New Hope”, where, at sunset, two stars of a binary pair dip low on the horizon.
But how would this multi-star system look from the vantage point of the exoplanet in 30 Ari? According to a NASA JPL news release, “the four parent stars would look like one small sun and two very bright stars that would be visible in daylight. One of those stars, if viewed with a large enough telescope, would be revealed to be a binary system, or two stars orbiting each other.”
Read more at Discovery News
Sun May Blast Two Jets of Plasma into Interstellar Space
As the sun travels through the galaxy, its extended magnetic bubble (known as the heliosphere), interacts with the gases and magnetism in the space between the stars — a vast region known as the interstellar medium.
However, astronomers have assumed that the heliosphere gets dragged out into a comet-like tail (not too dissimilar to a stretched-out raindrop), shaped by the interstellar medium, but scientists now think the sun’s magnetic field strength has been underestimated, overturning our understanding as to how our solar system looks from afar.
The heliosphere reaches far beyond the orbit of Pluto and it is filled with the energetic particles ejected by the sun contained within the solar wind. The sun’s magnetic field pushes outward with the solar wind, creating a magnetic bubble separating solar plasma from the interstellar medium. A balance of pressure between the outward pressure of the solar wind and the inward pressure of the interstellar medium is reached at the heliosphere’s boundary, called the heliopause.
As the sun is moving, it was assumed that the heliopause is being shaped through its interaction with the interstellar magnetic field, but new models and observations suggest that the sun’s magnetic field is actually dominating its shape. Rather than producing a ‘classical’ comet-like tail researchers now suggest two tails are formed from jets protruding from the sun’s north and south poles.
“Everyone’s assumption has been that the shape of the heliosphere was molded by the flow of interstellar material passing around it,” said astronomer Merav Opher, of Boston University, lead author of a paper published in the Astrophysical Journal Letters in February. “Scientists thought the solar wind flowing down the tail could easily pull the magnetic fields in the heliosphere along as it flowed by, creating this long tail. But it turns out the magnetic fields are strong enough to resist that pull — so instead they squeeze the solar wind and create these two jets.”
Interestingly, other stars in our galaxy have been observed with this two-jet heliosphere morphology, but now the mechanisms behind the two tails are being revealed inside our own solar system. For example, the star BZ Cam, below, exhibits a shortened heliosphere shaped by 2 jets:
The revelation that our basic comet-like model of the sun’s heliosphere was incomplete came when NASA’s Voyager 1 probe exited the heliosphere. On measuring the direction of the interstellar magnetic field — the first mission ever to do so — astronomers were surprised to find it matched the direction of our sun’s magnetic field, contrary to predictions.
By adding these findings to high-resolution computer simulations of the sun’s magnetic field, it became apparent that these jets had a strong influence over the heliosphere’s interstellar shape.
“If there were no interstellar flow, then the magnetic fields around the sun would shape the solar wind into two jets pointing straight north and south,” said co-author Jim Drake at the University of Maryland in College Park. “The magnetic fields contract around these jets, shooting the solar wind out like squishing a tube of toothpaste.”
Read more at Discovery News
However, astronomers have assumed that the heliosphere gets dragged out into a comet-like tail (not too dissimilar to a stretched-out raindrop), shaped by the interstellar medium, but scientists now think the sun’s magnetic field strength has been underestimated, overturning our understanding as to how our solar system looks from afar.
The heliosphere reaches far beyond the orbit of Pluto and it is filled with the energetic particles ejected by the sun contained within the solar wind. The sun’s magnetic field pushes outward with the solar wind, creating a magnetic bubble separating solar plasma from the interstellar medium. A balance of pressure between the outward pressure of the solar wind and the inward pressure of the interstellar medium is reached at the heliosphere’s boundary, called the heliopause.
As the sun is moving, it was assumed that the heliopause is being shaped through its interaction with the interstellar magnetic field, but new models and observations suggest that the sun’s magnetic field is actually dominating its shape. Rather than producing a ‘classical’ comet-like tail researchers now suggest two tails are formed from jets protruding from the sun’s north and south poles.
“Everyone’s assumption has been that the shape of the heliosphere was molded by the flow of interstellar material passing around it,” said astronomer Merav Opher, of Boston University, lead author of a paper published in the Astrophysical Journal Letters in February. “Scientists thought the solar wind flowing down the tail could easily pull the magnetic fields in the heliosphere along as it flowed by, creating this long tail. But it turns out the magnetic fields are strong enough to resist that pull — so instead they squeeze the solar wind and create these two jets.”
Interestingly, other stars in our galaxy have been observed with this two-jet heliosphere morphology, but now the mechanisms behind the two tails are being revealed inside our own solar system. For example, the star BZ Cam, below, exhibits a shortened heliosphere shaped by 2 jets:
The revelation that our basic comet-like model of the sun’s heliosphere was incomplete came when NASA’s Voyager 1 probe exited the heliosphere. On measuring the direction of the interstellar magnetic field — the first mission ever to do so — astronomers were surprised to find it matched the direction of our sun’s magnetic field, contrary to predictions.
By adding these findings to high-resolution computer simulations of the sun’s magnetic field, it became apparent that these jets had a strong influence over the heliosphere’s interstellar shape.
“If there were no interstellar flow, then the magnetic fields around the sun would shape the solar wind into two jets pointing straight north and south,” said co-author Jim Drake at the University of Maryland in College Park. “The magnetic fields contract around these jets, shooting the solar wind out like squishing a tube of toothpaste.”
Read more at Discovery News
Mar 3, 2015
Hundreds of Medieval Bodies Found Under Paris Supermarket
More than 200 bodies were recently unearthed in several mass burials beneath a Paris supermarket.
The bodies, which were lined up head to feet, were found at the site of an ancient cemetery attached to the Trinity Hospital, which was founded in the 13th century.
Though it's not clear exactly how these ancient people died, the trove of bodies could reveal insights into how people in the Middle Ages buried their dead during epidemics or famine, the researchers involved said.
Supermarket renovations
The burials were discovered during renovations to the basement of the Monoprix Réaumur-Sébastopol supermarket, located in the second-arrondissement neighborhood of Paris. As workers lowered the floor level of the basement, they found a shocking surprise: the bodies of men, women and children, neatly arranged in what looked to be mass graves.
The site was once the location of the Trinity Hospital, which was founded in 1202 by two German noblemen. The hospital was conceived not just as a place to provide care for the sick, but also as one where weary pilgrims and travelers could rest and enjoy themselves, according to a 1983 presentation given at the French Society on the History of Medicine.
But in 1353, during the height of the Black Death, the hospital also opened a cemetery, which provided a lucrative side business for the religious folk who operated the hospital, according to the presentation. During that catastrophic period, hundreds of people a day died in the Hôtel-Dieu de Paris, the city's oldest hospital, and burial space was tough to find in the crowded city. Occasionally, the overflow bodies were buried at the Trinity Hospital site, according to the presentation.
Mass death
So far, archaeologists have uncovered about eight mass burial pits on different levels of the site. Seven of those sites hold between five and 20 individuals, while the remaining pit contains more than 150 bodies, according to a statement about the findings.
The bodies were laid down methodically in neat rows, head to feet, with one burial extending beyond the boundaries of the excavation. The pits contain the skeletons of men and women, old and young, none of which show obvious signs of injury or disease.
Given the huge number of skeletons found, it seems likely the bodies were buried during some mass medical crisis, when too many people were dying at once to provide individual burials, the researchers note in the statement.
Read more at Discovery News
The bodies, which were lined up head to feet, were found at the site of an ancient cemetery attached to the Trinity Hospital, which was founded in the 13th century.
Though it's not clear exactly how these ancient people died, the trove of bodies could reveal insights into how people in the Middle Ages buried their dead during epidemics or famine, the researchers involved said.
Supermarket renovations
The burials were discovered during renovations to the basement of the Monoprix Réaumur-Sébastopol supermarket, located in the second-arrondissement neighborhood of Paris. As workers lowered the floor level of the basement, they found a shocking surprise: the bodies of men, women and children, neatly arranged in what looked to be mass graves.
The site was once the location of the Trinity Hospital, which was founded in 1202 by two German noblemen. The hospital was conceived not just as a place to provide care for the sick, but also as one where weary pilgrims and travelers could rest and enjoy themselves, according to a 1983 presentation given at the French Society on the History of Medicine.
But in 1353, during the height of the Black Death, the hospital also opened a cemetery, which provided a lucrative side business for the religious folk who operated the hospital, according to the presentation. During that catastrophic period, hundreds of people a day died in the Hôtel-Dieu de Paris, the city's oldest hospital, and burial space was tough to find in the crowded city. Occasionally, the overflow bodies were buried at the Trinity Hospital site, according to the presentation.
Mass death
So far, archaeologists have uncovered about eight mass burial pits on different levels of the site. Seven of those sites hold between five and 20 individuals, while the remaining pit contains more than 150 bodies, according to a statement about the findings.
The bodies were laid down methodically in neat rows, head to feet, with one burial extending beyond the boundaries of the excavation. The pits contain the skeletons of men and women, old and young, none of which show obvious signs of injury or disease.
Given the huge number of skeletons found, it seems likely the bodies were buried during some mass medical crisis, when too many people were dying at once to provide individual burials, the researchers note in the statement.
Read more at Discovery News
Origins of HIV Virus Strains Traced to Gorillas
Two of four strains of the virus that can cause AIDS come from gorillas in southwestern Cameroon, an international team of scientists reported in studies published Monday in the United States.
The new information means that researchers now know the origins of all strains of the HIV virus that occur in people.
HIV (HIV-1) has at least four strains. Known as Groups M, N, O and P, each one had its own origin -- from ape to man, on at least four separate occasions.
Groups M and N were known to have come from chimpanzees in Cameroon. But until now the origin of the O and P strains had been unknown.
Results of the study led by Martine Peeters, a virologist at France's Research and Development Institute (IRD) and the University of Montpellier, appeared in the Proceedings of the National Academy of Sciences.
HIV-1's Group M is the most widely spread, behind the greatest part of the epidemic with more than 40 million people now infected around the world.
Group P has only been detected in two people so far. And Group O has been found in central and western Africa, infecting about 100,000.
The breakthrough was made possible thanks to genetic samples from chimpanzees and gorillas from Cameroon, Gabon, Uganda and the Democratic Republic of Congo.
Read more at Discovery News
The new information means that researchers now know the origins of all strains of the HIV virus that occur in people.
HIV (HIV-1) has at least four strains. Known as Groups M, N, O and P, each one had its own origin -- from ape to man, on at least four separate occasions.
Groups M and N were known to have come from chimpanzees in Cameroon. But until now the origin of the O and P strains had been unknown.
Results of the study led by Martine Peeters, a virologist at France's Research and Development Institute (IRD) and the University of Montpellier, appeared in the Proceedings of the National Academy of Sciences.
HIV-1's Group M is the most widely spread, behind the greatest part of the epidemic with more than 40 million people now infected around the world.
Group P has only been detected in two people so far. And Group O has been found in central and western Africa, infecting about 100,000.
The breakthrough was made possible thanks to genetic samples from chimpanzees and gorillas from Cameroon, Gabon, Uganda and the Democratic Republic of Congo.
Read more at Discovery News
Albino Toddler in Africa Killed for Witchcraft
A toddler named Yohana Bahati was abducted from his home in northern Tanzania on Feb. 14, taken by two men armed with machetes. Police were called and fears were immediately raised because of the child’s rare genetic disorder, albinism. The condition results in a lack of pigmentation in the hair, skin, and eyes, giving them poor eyesight and extreme sensitivity to light. It also makes its sufferers a target for magic-related murder.
Bahati was soon found several kilometers from his home and the worst fears were realized. As a news article in “The Telegraph” described:
This horrific crime highlights the unusual intersection of magic beliefs, African culture, and government. This is only the latest in a series of albino murders. In Tanzania and Burundi, at least 50 albinos have been murdered for their body parts in recent years according to a 2010 Red Cross report. In November 2009, four people were arrested and sentenced to death in northern Tanzania for killing an albino man to harvest his body parts.
Throughout Africa witch doctors are consulted not only for healing diseases, but also for placing (or removing) magic curses or bringing luck in love or business. The belief and practice of using body parts for magical ritual or benefit is called muti.
Muti murders are particularly brutal, with knives and machetes used to cut and hack off limbs, breasts, and other body parts from their living victims. According to the United Nations albino body parts can sell for around $600 (or about what the average person earns in one year) in Tanzania.
Muti Magic
Earlier this year Tanzanian officials had reportedly banned witch doctors in an effort to prevent further witchcraft-related murders of people with albinism, but magical beliefs are deeply embedded in sub-Saharan cultures. Though the practice of muti specifically is not commonly practiced by witch doctors and traditional healers throughout Africa, it happens often enough (especially in East Africa) that albinos and their families live in constant fear for their lives.
What makes the death of Yohana Bahati especially tragic is his young age (most victims are older children or adults), and also the explanation for why the attacks have been increasing in recent months and may get worse: the use of magic by politicians in Tanzania’s upcoming elections to gain an advantage over their rivals.
As bizarre as it may sound to Westerners, the idea of using magic to gain an edge over an opponent — or for success in business or romance — is routine and commonplace throughout Africa. Witch doctors are hired to cast or remove curses, and if you believe that magic affects your daily life — as many Africans do — then obviously those with the most to gain or lose (such as those vying for public office) want the most powerful magic employed on their behalf.
Read more at Discovery News
Bahati was soon found several kilometers from his home and the worst fears were realized. As a news article in “The Telegraph” described:
“The mutilated body of an albino toddler has been found in Tanzania with his limbs hacked off, the latest such killing for body parts for witchcraft… police finding the body on Tuesday afternoon in a forest area close to his home. ‘His arms and legs were hacked off,’ regional police chief Joseph Konyo said. The baby’s mother Ester Jonas, aged 30, is in a serious state in (the) hospital with machete cuts to her face and arms after she tried to protect her baby.”
This horrific crime highlights the unusual intersection of magic beliefs, African culture, and government. This is only the latest in a series of albino murders. In Tanzania and Burundi, at least 50 albinos have been murdered for their body parts in recent years according to a 2010 Red Cross report. In November 2009, four people were arrested and sentenced to death in northern Tanzania for killing an albino man to harvest his body parts.
Throughout Africa witch doctors are consulted not only for healing diseases, but also for placing (or removing) magic curses or bringing luck in love or business. The belief and practice of using body parts for magical ritual or benefit is called muti.
Muti murders are particularly brutal, with knives and machetes used to cut and hack off limbs, breasts, and other body parts from their living victims. According to the United Nations albino body parts can sell for around $600 (or about what the average person earns in one year) in Tanzania.
Muti Magic
Earlier this year Tanzanian officials had reportedly banned witch doctors in an effort to prevent further witchcraft-related murders of people with albinism, but magical beliefs are deeply embedded in sub-Saharan cultures. Though the practice of muti specifically is not commonly practiced by witch doctors and traditional healers throughout Africa, it happens often enough (especially in East Africa) that albinos and their families live in constant fear for their lives.
What makes the death of Yohana Bahati especially tragic is his young age (most victims are older children or adults), and also the explanation for why the attacks have been increasing in recent months and may get worse: the use of magic by politicians in Tanzania’s upcoming elections to gain an advantage over their rivals.
As bizarre as it may sound to Westerners, the idea of using magic to gain an edge over an opponent — or for success in business or romance — is routine and commonplace throughout Africa. Witch doctors are hired to cast or remove curses, and if you believe that magic affects your daily life — as many Africans do — then obviously those with the most to gain or lose (such as those vying for public office) want the most powerful magic employed on their behalf.
Read more at Discovery News
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Hunt for Dwarf Planet Ceres' Mysterious Water Begins
NASA’s Dawn spacecraft is about to make its second and final stop during its exploration of the asteroid belt and it is already returning some stunning images that are creating more questions than answers.
After leaving massive asteroid Vesta’s orbit in 2012, Dawn has traveled through the asteroid belt that occupies the region between the orbits of Mars and Jupiter to rendezvous with 600 mile-wide dwarf planet Ceres — the first spacecraft ever to orbit two celestial bodies during its mission.
The probe will be captured by Ceres’ gravity on Friday, March 6, and in the run-up to this highly anticipated event, the probe has been sending back increasingly detailed observations of the solar system’s innermost dwarf planet that are already puzzling planetary scientists. One puzzle focuses on bright patches on the Cererian landscape — one of which is a particularly bright spot, with a dimmer partner, inside an impact crater.
Speaking during Monday’s press conference at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., Dawn deputy project scientist Carol Raymond outlined some possibilities that may explain these strange features. As previously reported, one mechanism that could be creating the bright patches is cryovolcanism, where sub-surface ice is forced to the surface. But as Dawn’s imagery becomes sharper by the day, this mechanism is looking less likely.
“A cryovolcano will likely result in a constructional feature,” said Raymond. “So we’d expect to see a mounded feature on the surface — some sort of deposit around a central vent or a crack. In the case of this crater, what we can say is that the brightest spot is not associated with a ‘positive relief feature’ — i.e. a mound or peak … so a cryovolcano is not at the top of the list for that feature.”
We’ll have to wait until Dawn has completed its first science orbit (in late-April) so the probe’s instrumentation can be better calibrated to understand just why these spots are so bright and, ultimately, understand their origin.
Although cryovolcanism may be looking less and less likely, the mystery of Ceres’ water is one of most exciting unknowns on the minds of the Dawn team.
“One of the mysteries is that of liquid water,” Dawn mission director and chief engineer Marc Rayman told Discovery News. “Are there sub-surface reservoirs of water — ponds or lakes or oceans? I think that’s really exciting.”
From observations and theoretical models, scientists have a pretty good idea that Ceres was a planet in the making in the early epochs of the solar system. It is composed of stratified material and from density models of the world, there are strong indications that there should be sub-surface reservoirs of water.
As Ceres isn’t heated by the the tidal heating that Saturn’s moon Enceladus or Jupiter’s moon Europa experience and receives weak sunlight as its only heat source, it is most likely that if Ceres did have sub-surface liquid water reservoirs early in its history, they are likely now long frozen, unless interactions with minerals in the rocks produced salts to maintain a liquid state.
The expectation that Dawn would see Ceres covered with ice was further bolstered last year when the ESA Herschel space telescope detected water vapor in the vicinity of Ceres. Although it wasn’t a huge quantity, it did boost hopes that Ceres may be venting water vapor into space from its sub-surface reservoirs, in a similar (but more understated) manner to Enceladus’ impressive south pole geysers. Another theory is that, by chance, Herschel may have spotted the after effects of a meteorite impact on Ceres that kicked up surface ice into space.
Before Dawn started its approach of Ceres, it seemed highly possible that Ceres was going to have more in common with Enceladus and Europa — two icy worlds with sub-surface oceans. As it turns out, as Ceres came into focus, its ancient cratered surface, as opposed to an ice-covered crust, came as a surprise.
“That was the biggest surprise I think for me and many of the team members — when we saw those craters we were like ‘Okay…’,” Raymond told Discovery News. “The ice should be close to the surface, it flows. So something else is going on. There’s lots of ideas as to how we can explain that but we’re going to have to sharpen our pencils, do a lot of detailed models and we’re going to need a little more insight from high-resolution data (from Dawn).”
There is still a possibility that water vapor may be escaping from the dwarf planet, but Dawn’s instrumentation isn’t designed to specifically seek out venting regions. But through the use of its infrared spectrometer, Dawn may be able to detect the back-scattered light created by dust that is being blown into space by the venting water vapor. A “tenuous atmosphere about Ceres” may also be a possibility, according to Raymond.
“Since I have the meteorology background, I most want to know what’s going on with the water vapor, maybe there’s an atmospheric thing going on,” Keri Bean, Dawn mission operations engineer, told Discovery News. “Dawn will give us an answer, one way or another. It may not be able to see it (the water vapor), but that will also be a clue. So it will be interesting to see what Dawn does.”
Rather than answering any questions early in Dawn’s Ceres encounter, it seems even more questions are popping up.
“The real excitement is, what does Ceres have to tell us? It’s not a specific question; it’s rather that this is a mysterious alien world that, for two centuries has just been this faint smudge of light,” added Rayman. “Now we’re finally getting this in-depth, richly detailed portrait. That’s what I think is exciting.
“What questions is Ceres going to answer that we’re not even smart enough to ask now?”
Read more at Discovery News
After leaving massive asteroid Vesta’s orbit in 2012, Dawn has traveled through the asteroid belt that occupies the region between the orbits of Mars and Jupiter to rendezvous with 600 mile-wide dwarf planet Ceres — the first spacecraft ever to orbit two celestial bodies during its mission.
The probe will be captured by Ceres’ gravity on Friday, March 6, and in the run-up to this highly anticipated event, the probe has been sending back increasingly detailed observations of the solar system’s innermost dwarf planet that are already puzzling planetary scientists. One puzzle focuses on bright patches on the Cererian landscape — one of which is a particularly bright spot, with a dimmer partner, inside an impact crater.
Speaking during Monday’s press conference at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., Dawn deputy project scientist Carol Raymond outlined some possibilities that may explain these strange features. As previously reported, one mechanism that could be creating the bright patches is cryovolcanism, where sub-surface ice is forced to the surface. But as Dawn’s imagery becomes sharper by the day, this mechanism is looking less likely.
“A cryovolcano will likely result in a constructional feature,” said Raymond. “So we’d expect to see a mounded feature on the surface — some sort of deposit around a central vent or a crack. In the case of this crater, what we can say is that the brightest spot is not associated with a ‘positive relief feature’ — i.e. a mound or peak … so a cryovolcano is not at the top of the list for that feature.”
We’ll have to wait until Dawn has completed its first science orbit (in late-April) so the probe’s instrumentation can be better calibrated to understand just why these spots are so bright and, ultimately, understand their origin.
Although cryovolcanism may be looking less and less likely, the mystery of Ceres’ water is one of most exciting unknowns on the minds of the Dawn team.
“One of the mysteries is that of liquid water,” Dawn mission director and chief engineer Marc Rayman told Discovery News. “Are there sub-surface reservoirs of water — ponds or lakes or oceans? I think that’s really exciting.”
From observations and theoretical models, scientists have a pretty good idea that Ceres was a planet in the making in the early epochs of the solar system. It is composed of stratified material and from density models of the world, there are strong indications that there should be sub-surface reservoirs of water.
As Ceres isn’t heated by the the tidal heating that Saturn’s moon Enceladus or Jupiter’s moon Europa experience and receives weak sunlight as its only heat source, it is most likely that if Ceres did have sub-surface liquid water reservoirs early in its history, they are likely now long frozen, unless interactions with minerals in the rocks produced salts to maintain a liquid state.
The expectation that Dawn would see Ceres covered with ice was further bolstered last year when the ESA Herschel space telescope detected water vapor in the vicinity of Ceres. Although it wasn’t a huge quantity, it did boost hopes that Ceres may be venting water vapor into space from its sub-surface reservoirs, in a similar (but more understated) manner to Enceladus’ impressive south pole geysers. Another theory is that, by chance, Herschel may have spotted the after effects of a meteorite impact on Ceres that kicked up surface ice into space.
Before Dawn started its approach of Ceres, it seemed highly possible that Ceres was going to have more in common with Enceladus and Europa — two icy worlds with sub-surface oceans. As it turns out, as Ceres came into focus, its ancient cratered surface, as opposed to an ice-covered crust, came as a surprise.
“That was the biggest surprise I think for me and many of the team members — when we saw those craters we were like ‘Okay…’,” Raymond told Discovery News. “The ice should be close to the surface, it flows. So something else is going on. There’s lots of ideas as to how we can explain that but we’re going to have to sharpen our pencils, do a lot of detailed models and we’re going to need a little more insight from high-resolution data (from Dawn).”
There is still a possibility that water vapor may be escaping from the dwarf planet, but Dawn’s instrumentation isn’t designed to specifically seek out venting regions. But through the use of its infrared spectrometer, Dawn may be able to detect the back-scattered light created by dust that is being blown into space by the venting water vapor. A “tenuous atmosphere about Ceres” may also be a possibility, according to Raymond.
“Since I have the meteorology background, I most want to know what’s going on with the water vapor, maybe there’s an atmospheric thing going on,” Keri Bean, Dawn mission operations engineer, told Discovery News. “Dawn will give us an answer, one way or another. It may not be able to see it (the water vapor), but that will also be a clue. So it will be interesting to see what Dawn does.”
Rather than answering any questions early in Dawn’s Ceres encounter, it seems even more questions are popping up.
“The real excitement is, what does Ceres have to tell us? It’s not a specific question; it’s rather that this is a mysterious alien world that, for two centuries has just been this faint smudge of light,” added Rayman. “Now we’re finally getting this in-depth, richly detailed portrait. That’s what I think is exciting.
“What questions is Ceres going to answer that we’re not even smart enough to ask now?”
Read more at Discovery News
Could This Alien Cell Thrive on Titan?
In a world first, chemical engineers have taken a different look at a question astronomers and biologists have been pondering for decades: Does Saturn moon Titan host life?
Of course, Titan is way too hostile for life as we know it to eke out an existence — it is a frigid world awash with liquid methane and ethane and a noxious atmosphere devoid of any liquid water. But what if there is a different kind of biology, a life as we don’t know it, thriving on the organic chemistry that is abundant on Titan’s surface?
Normally, astrobiologists combine what we know about Earth’s biosphere and astronomers zoom in on other stars containing exoplanets in the hope that some of those alien world have some similarities to Earth. By looking for small rocky exoplanets orbiting inside their star’s habitable zones, we are basically looking for a “second Earth” where liquid water is at least possible. Where there’s liquid water on Earth, there’s inevitably life, so scientists seeking out alien life "follow the water" in the hope of finding life with a similar terrestrial template on other planets.
Titan, however, does not fall into this category. It's about as un-Earth-like as you can get. So, chemical molecular dynamics expert Paulette Clancy, astronomer Jonathan Lunine and James Stevenson, a graduate student in chemical engineering, all from Cornell University, Ithaca, N.Y., have looked at Titan in a different light and created a theoretical model of a methane-based, oxygen-free life form that could thrive in that environment.
There is no known template for this kind of life on Earth, but the researchers have studied what chemicals are in abundance on Titan and worked out how a very different kind of life could be sparked.
As a collaborator on the NASA/ESA Cassini-Huygens mission, Lunine, Professor in the Physical Sciences in the College of Arts and Sciences’ Department of Astronomy, has been fascinated with the possibility of methane-based life existing on Titan for some time, so he joined forces with Clancy and Stevenson to see what this hypothetical life form might look like.
In their research published in the journal Science Advances on Feb. 27, the researchers focused on building a cell membrane “composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero (Fahrenheit; or 94 Kelvin),” said a Cornell press release. On Earth, water-based molecules form phospholipid bilayer membranes that give cells structure, housing organic materials inside while remaining permeable. On Titan, liquid water isn’t available to build these cell membranes.
“We’re not biologists, and we’re not astronomers, but we had the right tools,” said Clancy, lead researcher of the study. “Perhaps it helped, because we didn’t come in with any preconceptions about what should be in a membrane and what shouldn’t. We just worked with the compounds that we knew were there and asked, ‘If this was your palette, what can you make out of that?’”
The researchers were able to model the ideal cell that can do all the things that life can do (i.e. support metabolism and reproduction), but constructed it from nitrogen, carbon and hydrogen-based molecules that are known to exist in Titan’s liquid methane seas. This chemical configuration gives this theoretical alien cell stability and flexibility in a similar manner to Earth life cells.
“Ours is the first concrete blueprint of life not as we know it,” said lead author Stevenson, who also said that he was inspired, in part, by Isaac Asimov, who wrote the 1962 essay “Not as We Know It” about non-water-based life.
Read more at Discovery News
Of course, Titan is way too hostile for life as we know it to eke out an existence — it is a frigid world awash with liquid methane and ethane and a noxious atmosphere devoid of any liquid water. But what if there is a different kind of biology, a life as we don’t know it, thriving on the organic chemistry that is abundant on Titan’s surface?
Normally, astrobiologists combine what we know about Earth’s biosphere and astronomers zoom in on other stars containing exoplanets in the hope that some of those alien world have some similarities to Earth. By looking for small rocky exoplanets orbiting inside their star’s habitable zones, we are basically looking for a “second Earth” where liquid water is at least possible. Where there’s liquid water on Earth, there’s inevitably life, so scientists seeking out alien life "follow the water" in the hope of finding life with a similar terrestrial template on other planets.
Titan, however, does not fall into this category. It's about as un-Earth-like as you can get. So, chemical molecular dynamics expert Paulette Clancy, astronomer Jonathan Lunine and James Stevenson, a graduate student in chemical engineering, all from Cornell University, Ithaca, N.Y., have looked at Titan in a different light and created a theoretical model of a methane-based, oxygen-free life form that could thrive in that environment.
There is no known template for this kind of life on Earth, but the researchers have studied what chemicals are in abundance on Titan and worked out how a very different kind of life could be sparked.
As a collaborator on the NASA/ESA Cassini-Huygens mission, Lunine, Professor in the Physical Sciences in the College of Arts and Sciences’ Department of Astronomy, has been fascinated with the possibility of methane-based life existing on Titan for some time, so he joined forces with Clancy and Stevenson to see what this hypothetical life form might look like.
In their research published in the journal Science Advances on Feb. 27, the researchers focused on building a cell membrane “composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero (Fahrenheit; or 94 Kelvin),” said a Cornell press release. On Earth, water-based molecules form phospholipid bilayer membranes that give cells structure, housing organic materials inside while remaining permeable. On Titan, liquid water isn’t available to build these cell membranes.
“We’re not biologists, and we’re not astronomers, but we had the right tools,” said Clancy, lead researcher of the study. “Perhaps it helped, because we didn’t come in with any preconceptions about what should be in a membrane and what shouldn’t. We just worked with the compounds that we knew were there and asked, ‘If this was your palette, what can you make out of that?’”
The researchers were able to model the ideal cell that can do all the things that life can do (i.e. support metabolism and reproduction), but constructed it from nitrogen, carbon and hydrogen-based molecules that are known to exist in Titan’s liquid methane seas. This chemical configuration gives this theoretical alien cell stability and flexibility in a similar manner to Earth life cells.
“The engineers named their theorized cell membrane an ‘azotosome,’ ‘azote’ being the French word for nitrogen. ‘Liposome’ comes from the Greek ‘lipos’ and ‘soma’ to mean ‘lipid body;’ by analogy, ‘azotosome’ means ‘nitrogen body.’” — Cornell
“Ours is the first concrete blueprint of life not as we know it,” said lead author Stevenson, who also said that he was inspired, in part, by Isaac Asimov, who wrote the 1962 essay “Not as We Know It” about non-water-based life.
Read more at Discovery News
Mar 2, 2015
'Skeletorus' and 'Sparklemuffin' the Newest Spiders
Two gorgeous new species of peacock spiders nicknamed "Skeletorus" and "Sparklemuffin" have been discovered in Australia, according to a new report.
Peacock spiders are so-named because of their bright colors and their dancelike, courtship rituals.
The two new species were found in southeast Queensland by Madeline Girard, a graduate student at the University of California, Berkeley who studies peacock spiders, and a friend who went with her into the field. Girard affectionately gave the nickname Sparklemuffin to one of the species, Maratus jactatus, which has bluish and reddish stripes on its abdomen.
She nicknamed the other species Skeletorus for its white markings on a black background, which make it look a bit like a skeleton. Sparklemuffin looks similar to three previously discovered species in this group of peacock spiders, whereas Skeletorus looks very different from all the other known species in the group.
In fact, Skeletorus, officially named Maratus sceletus, "looks dramatically different all other peacock spiders known to date, making me think that this group is perhaps much more diverse than we had thought," said Jürgen Otto, an entomologist who specializes in photographing the arachnids and who co-authored the report.
"Despite the large number of species we have discovered just in the last few years, I can't help feeling that we may have just scratched the surface of this most exciting group of spiders, and that nature has quite a few more surprises in store," Otto told Live Science.
The first peacock spider was discovered in the 1800s, said study co-author David Hill, the editor of the journal Peckhamia, which published the new report on Jan. 20. But then, "for more than 100 years, almost nobody looked at these animals," until Otto started photographing them and recording their courtship displays, Hill said. The spiders are very small, measuring between 3 and 7 millimeters (0.1 to 0.3 inches) long, he added.
Both Sparklemuffin and Skeletorus, along with the three other known species that belong to the calcitrans peacock spider group, share certain similarities, some of which have a lot to do with the way the arachnids perform their characteristic mating dances. For instance, the males display a flap-like body part called a fan that is adorned with a pattern of bold, transverse stripes, according to the report. They also raise a single leg, displaying it to the female.
Read more at Discovery News
Peacock spiders are so-named because of their bright colors and their dancelike, courtship rituals.
The two new species were found in southeast Queensland by Madeline Girard, a graduate student at the University of California, Berkeley who studies peacock spiders, and a friend who went with her into the field. Girard affectionately gave the nickname Sparklemuffin to one of the species, Maratus jactatus, which has bluish and reddish stripes on its abdomen.
She nicknamed the other species Skeletorus for its white markings on a black background, which make it look a bit like a skeleton. Sparklemuffin looks similar to three previously discovered species in this group of peacock spiders, whereas Skeletorus looks very different from all the other known species in the group.
In fact, Skeletorus, officially named Maratus sceletus, "looks dramatically different all other peacock spiders known to date, making me think that this group is perhaps much more diverse than we had thought," said Jürgen Otto, an entomologist who specializes in photographing the arachnids and who co-authored the report.
"Despite the large number of species we have discovered just in the last few years, I can't help feeling that we may have just scratched the surface of this most exciting group of spiders, and that nature has quite a few more surprises in store," Otto told Live Science.
The first peacock spider was discovered in the 1800s, said study co-author David Hill, the editor of the journal Peckhamia, which published the new report on Jan. 20. But then, "for more than 100 years, almost nobody looked at these animals," until Otto started photographing them and recording their courtship displays, Hill said. The spiders are very small, measuring between 3 and 7 millimeters (0.1 to 0.3 inches) long, he added.
Both Sparklemuffin and Skeletorus, along with the three other known species that belong to the calcitrans peacock spider group, share certain similarities, some of which have a lot to do with the way the arachnids perform their characteristic mating dances. For instance, the males display a flap-like body part called a fan that is adorned with a pattern of bold, transverse stripes, according to the report. They also raise a single leg, displaying it to the female.
Read more at Discovery News
Emperor Penguins May Have Suffered in Ice Age Cold
They prefer freezing conditions but Antarctica's emperor penguins may have struggled with the cold during the last Ice Age when temperatures cooled, a study suggested Monday.
Researchers looking at how climatic changes have affected the highly cold-adapted penguin -- the tallest and heaviest of all penguin species -- over the last 30,000 years suggest that there were only three populations in the last ice age.
But as temperatures have warmed up since then, the species has flourished and there are now seven times more of the penguins in many more locations, said joint lead researcher Jane Younger.
"We hadn't really thought about the fact that it would be too cold for them in the past," Younger, a PhD student at the University of Tasmania, told AFP.
"They live through life in minus 30 degrees Celsius (-22 Fahrenheit) now so they are pretty cold adapted."
By examining the genetic diversity of modern and ancient penguin populations, scientists from the universities of Tasmania, Southampton and Oxford in Britain, and the Australian Antarctic Division were able to estimate their numbers over time.
They found that numbers began increasing over the last 12,000 years when temperatures rose by an average of about 15 degrees Celsius and as the amount of sea ice around Antarctica began to reduce.
Younger said the warmer temperatures likely gave penguin chicks a better chance of surviving the winter -- when temperatures would have dropped to minus 45 degrees Celsius during the ice age.
Too much sea ice could have also reduced the locations for breeding, while a shrinking of the ice would have allowed them easier access to the open ocean to feed, she said.
"We were actually really surprised by this. What we had thought was that the ice age, because there was so much more sea ice, which they need (to breed), and because they are so cold-adapted, that this would probably be a good thing for them," she said.
Emperor penguins, which can get heat stress with temperatures above zero, breed during the winter, with the males keeping the egg safe and warm during the cold months.
"What happens occasionally is that the egg will get dropped onto the ice, and these days they can usually get the egg back and it will be alright if it was not out too long," Younger said.
"But the temperatures during the ice age were about 15 degrees colder so... if the egg was dropped it would have been in pretty serious danger almost straight away. And the same thing once the chicks have hatched out of the egg, they need to be kept warm throughout the winter."
The researchers believe a population survived in the Ross Sea region because an area of ocean was always kept free of sea ice by wind and currents, according to the study published in Global Change Biology.
Read more at Discovery News
Researchers looking at how climatic changes have affected the highly cold-adapted penguin -- the tallest and heaviest of all penguin species -- over the last 30,000 years suggest that there were only three populations in the last ice age.
But as temperatures have warmed up since then, the species has flourished and there are now seven times more of the penguins in many more locations, said joint lead researcher Jane Younger.
"We hadn't really thought about the fact that it would be too cold for them in the past," Younger, a PhD student at the University of Tasmania, told AFP.
"They live through life in minus 30 degrees Celsius (-22 Fahrenheit) now so they are pretty cold adapted."
By examining the genetic diversity of modern and ancient penguin populations, scientists from the universities of Tasmania, Southampton and Oxford in Britain, and the Australian Antarctic Division were able to estimate their numbers over time.
They found that numbers began increasing over the last 12,000 years when temperatures rose by an average of about 15 degrees Celsius and as the amount of sea ice around Antarctica began to reduce.
Younger said the warmer temperatures likely gave penguin chicks a better chance of surviving the winter -- when temperatures would have dropped to minus 45 degrees Celsius during the ice age.
Too much sea ice could have also reduced the locations for breeding, while a shrinking of the ice would have allowed them easier access to the open ocean to feed, she said.
"We were actually really surprised by this. What we had thought was that the ice age, because there was so much more sea ice, which they need (to breed), and because they are so cold-adapted, that this would probably be a good thing for them," she said.
Emperor penguins, which can get heat stress with temperatures above zero, breed during the winter, with the males keeping the egg safe and warm during the cold months.
"What happens occasionally is that the egg will get dropped onto the ice, and these days they can usually get the egg back and it will be alright if it was not out too long," Younger said.
"But the temperatures during the ice age were about 15 degrees colder so... if the egg was dropped it would have been in pretty serious danger almost straight away. And the same thing once the chicks have hatched out of the egg, they need to be kept warm throughout the winter."
The researchers believe a population survived in the Ross Sea region because an area of ocean was always kept free of sea ice by wind and currents, according to the study published in Global Change Biology.
Read more at Discovery News
25 Tons of Pigeon Poo Found in Medieval Monument
A medieval monument in England underwent a dramatic cleaning when a high pressure tanker sucked up about 25 tons of pigeon poo from the historic structure.
Measuring almost three feet deep, the bird droppings built up over decades inside the towers of the roofless 14th-century Landgate Arch in Rye, East Sussex.
Since there is no public access to the towers, the massive, mushy mess went unnoticed until last month, when members of the Rother District Council, which owns the ancient monument, made the stomach-turning finding.
“Whilst we’ve removed other massive blockages such giant fatbergs in sewers, we have never seen such a monumental mass of festering feces before,” Mike Walker, managing director for CountyClean Environmental Services, appointed to clean the towers last week, said in a statement.
He added that the build up behind the doors was such that cleaners had to force the doors open.
“Once inside, it was like walking on a giant chocolate cake and the smell was awful –- even through a facemask,” he said.
Had the guano not been removed, it would have continued to accumulate and cause structural damage to the monument. The acidic pigeon poo can damage stonework seriously.
The clean-up took four days using a powerful custom built machine.
“The machine provides high powered vacuum suction through hoses as well as high pressure water jetting,” Graeme Sanderson at CountyClean Environmental Services told Discovery News.
Read more at Discovery News
Measuring almost three feet deep, the bird droppings built up over decades inside the towers of the roofless 14th-century Landgate Arch in Rye, East Sussex.
Since there is no public access to the towers, the massive, mushy mess went unnoticed until last month, when members of the Rother District Council, which owns the ancient monument, made the stomach-turning finding.
“Whilst we’ve removed other massive blockages such giant fatbergs in sewers, we have never seen such a monumental mass of festering feces before,” Mike Walker, managing director for CountyClean Environmental Services, appointed to clean the towers last week, said in a statement.
He added that the build up behind the doors was such that cleaners had to force the doors open.
“Once inside, it was like walking on a giant chocolate cake and the smell was awful –- even through a facemask,” he said.
Had the guano not been removed, it would have continued to accumulate and cause structural damage to the monument. The acidic pigeon poo can damage stonework seriously.
The clean-up took four days using a powerful custom built machine.
“The machine provides high powered vacuum suction through hoses as well as high pressure water jetting,” Graeme Sanderson at CountyClean Environmental Services told Discovery News.
Read more at Discovery News
Coffin-Within-a-Coffin Opened at Richard III Grave
A mysterious lead coffin found close to King Richard III’s grave beneath a parking lot in Leicester, England, contained the skeleton of an elderly woman, archaeologists at Leicester University announced today.
Featuring an inlaid crucifix, carefully soldered on all sides but with feet sticking out of the bottom, the lead coffin was discovered inside a larger limestone sarcophagus in August 2013 . The discovery came one year after the battle-scarred remains of the last Plantagenet king of England — the family ruled vast areas of Europe — were unearthed.
Radiocarbon dating suggests the lady in the lead casket might have died as late as 1400, although it's much more likely she was buried in the last half of the 13th century — long before Richard III’s death at the Battle of Bosworth.
Although her sarcophagus was the first intact medieval stone coffin unearthed in the area, it wasn’t the only grave found at the site. Nine other burials were identified beneath the car park, which was basically the site of Grey Friars Church, the medieval friary of the Franciscans known to have been Richard III’s final resting place.
Established in around 1250, the friary was demolished in 1538, as part of King Henry VIII’s Dissolution of the Monasteries.
“There is the potential for hundreds more burials elsewhere inside the church, the other friary buildings and outside in the cemetery,” said Grey Friars site director Mathew Morris, who led the dig.
The mysterious coffin-within-a-coffin prompted various speculations about the individual it contained. All suggested it was a male.
The guessing game included two leaders of the English Grey Friars order -- Peter Swynsfeld, who died in 1272, and William of Nottingham, who died in 1330.
“We speculated that this grave might be for one of them. To find that it contained a woman was intriguing and to some extent frustrating for we know much less about the women associated with the friary than the men,” Morris told Discovery News.
Three graves exhumed out of the 10 found so far at the Grey Friars turned to contain female skeletons.
“The discovery is going to add important insights into the interaction of women and the religious orders in the medieval period,” Morris said.
He noted that statistically, the sample is too small to draw any conclusions to the significance of women’s presence at Grey Friars. Richard III, who will be reinterred in Leicester Cathedral on March 26, would certainly not have been the only male buried there during the friary’s 300 year history.
“After all, if we carried out more excavations it is possible that we could find that these are the only four women buried in the church,” Morris said.
Two graves inside the choir -- where Richard III was found -- contained wooden coffins and two females aged between 40 and 50 years-old. Radiocarbon dating indicate they died between 1270 and 1400.
One of the women likely had a congenital hip dislocation which forced her to walk with a crutch, while the other lived a life of hard physical labor, regularly using her arms and legs to lift heavy weights.
Another female skeleton, believed to have died in her early to mid-20s, also led a life of hard physical work.
Analysis of the female remains, including the lady in the lead coffin, who was over 60 when she died, revealed that all four women had a highly varied, protein-rich diet including large amounts of sea fish. This indicates that they would have been wealthy, the archaeologists concluded.
“The friary’s main source of donations came from the town’s middle classes, merchants and tradespeople who were probably of more modest means, and worked for a living,” Morris said.
Buried in a prominent position in the church, the lady in the lead coffin was certainly enjoying a high social status.
Read more at Discovery News
Featuring an inlaid crucifix, carefully soldered on all sides but with feet sticking out of the bottom, the lead coffin was discovered inside a larger limestone sarcophagus in August 2013 . The discovery came one year after the battle-scarred remains of the last Plantagenet king of England — the family ruled vast areas of Europe — were unearthed.
Radiocarbon dating suggests the lady in the lead casket might have died as late as 1400, although it's much more likely she was buried in the last half of the 13th century — long before Richard III’s death at the Battle of Bosworth.
Although her sarcophagus was the first intact medieval stone coffin unearthed in the area, it wasn’t the only grave found at the site. Nine other burials were identified beneath the car park, which was basically the site of Grey Friars Church, the medieval friary of the Franciscans known to have been Richard III’s final resting place.
Established in around 1250, the friary was demolished in 1538, as part of King Henry VIII’s Dissolution of the Monasteries.
“There is the potential for hundreds more burials elsewhere inside the church, the other friary buildings and outside in the cemetery,” said Grey Friars site director Mathew Morris, who led the dig.
The mysterious coffin-within-a-coffin prompted various speculations about the individual it contained. All suggested it was a male.
The guessing game included two leaders of the English Grey Friars order -- Peter Swynsfeld, who died in 1272, and William of Nottingham, who died in 1330.
“We speculated that this grave might be for one of them. To find that it contained a woman was intriguing and to some extent frustrating for we know much less about the women associated with the friary than the men,” Morris told Discovery News.
Three graves exhumed out of the 10 found so far at the Grey Friars turned to contain female skeletons.
“The discovery is going to add important insights into the interaction of women and the religious orders in the medieval period,” Morris said.
He noted that statistically, the sample is too small to draw any conclusions to the significance of women’s presence at Grey Friars. Richard III, who will be reinterred in Leicester Cathedral on March 26, would certainly not have been the only male buried there during the friary’s 300 year history.
“After all, if we carried out more excavations it is possible that we could find that these are the only four women buried in the church,” Morris said.
Two graves inside the choir -- where Richard III was found -- contained wooden coffins and two females aged between 40 and 50 years-old. Radiocarbon dating indicate they died between 1270 and 1400.
One of the women likely had a congenital hip dislocation which forced her to walk with a crutch, while the other lived a life of hard physical labor, regularly using her arms and legs to lift heavy weights.
Another female skeleton, believed to have died in her early to mid-20s, also led a life of hard physical work.
Analysis of the female remains, including the lady in the lead coffin, who was over 60 when she died, revealed that all four women had a highly varied, protein-rich diet including large amounts of sea fish. This indicates that they would have been wealthy, the archaeologists concluded.
“The friary’s main source of donations came from the town’s middle classes, merchants and tradespeople who were probably of more modest means, and worked for a living,” Morris said.
Buried in a prominent position in the church, the lady in the lead coffin was certainly enjoying a high social status.
Read more at Discovery News
Mar 1, 2015
First detailed microscopy evidence of bacteria at the lower size limit of life
Scientists have captured the first detailed microscopy images of ultra-small bacteria that are believed to be about as small as life can get. The research was led by scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California, Berkeley. The existence of ultra-small bacteria has been debated for two decades, but there hasn't been a comprehensive electron microscopy and DNA-based description of the microbes until now.
The cells have an average volume of 0.009 cubic microns (one micron is one millionth of a meter). About 150 of these bacteria could fit inside an Escherichia coli cell and more than 150,000 cells could fit onto the tip of a human hair.
The scientists report their findings Friday, Feb. 27, in the journal Nature Communications.
The diverse bacteria were found in groundwater and are thought to be quite common. They're also quite odd, which isn't a surprise given the cells are close to and in some cases smaller than several estimates for the lower size limit of life. This is the smallest a cell can be and still accommodate enough material to sustain life. The bacterial cells have densely packed spirals that are probably DNA, a very small number of ribosomes, hair-like appendages, and a stripped-down metabolism that likely requires them to rely on other bacteria for many of life's necessities.
The bacteria are from three microbial phyla that are poorly understood. Learning more about the organisms from these phyla could shed light on the role of microbes in the planet's climate, our food and water supply, and other key processes.
"These newly described ultra-small bacteria are an example of a subset of the microbial life on earth that we know almost nothing about," says Jill Banfield, a Senior Faculty Scientist in Berkeley Lab's Earth Sciences Division and a UC Berkeley professor in the departments of Earth and Planetary Science and Environmental Science, Policy and Management.
"They're enigmatic. These bacteria are detected in many environments and they probably play important roles in microbial communities and ecosystems. But we don't yet fully understand what these ultra-small bacteria do," says Banfield.
Banfield is a co-corresponding author of the Nature Communications paper with Birgit Luef, a former postdoctoral researcher in Banfield's group who is now at the Norwegian University of Science and Technology, Trondheim.
"There isn't a consensus over how small a free-living organism can be, and what the space optimization strategies may be for a cell at the lower size limit for life. Our research is a significant step in characterizing the size, shape, and internal structure of ultra-small cells," says Luef.
The scientists set out to study bacteria from phyla that lack cultivated representatives. Some of these bacteria have very small genomes, so the scientists surmised the bacteria themselves might also be very small.
To concentrate these cells in a sample, they filtered groundwater collected at Rifle, Colorado through successively smaller filters, down to 0.2 microns, which is the size used to sterilize water. The resulting samples were anything but sterile. They were enriched with incredibly tiny microbes, which were flash frozen to -272 degrees Celsius in a first-of-its-kind portable version of a device called a cryo plunger. This ensured the microbes weren't damaged in their journey from the field to the lab.
The frozen samples were transported to Berkeley Lab, where Luef, with the help of Luis Comolli of Berkeley Lab's Life Sciences Division, characterized the cells' size and internal structure using 2-D and 3-D cryogenic transmission electron microscopy. The images also revealed dividing cells, indicating the bacteria were healthy and not starved to an abnormally small size.
The bacteria's genomes were sequenced at the Joint Genome Institute, a DOE Office of Science User Facility located in Walnut Creek, California, under the guidance of Susannah Tringe. The genomes were about one million base pairs in length. In addition, metagenomic and other DNA-based analyses of the samples were conducted at UC Berkeley, which found a diverse range of bacteria from WWE3, OP11, and OD1 phyla.
This combination of innovative fieldwork and state-of-the-art microscopy and genomic analysis yielded the most complete description of ultra-small bacteria to date.
Among their findings: Some of the bacteria have thread-like appendages, called pili, which could serve as "life support" connections to other microbes. The genomic data indicates the bacteria lack many basic functions, so they likely rely on a community of microbes for critical resources.
The scientists also discovered just how much there is yet to learn about ultra-small life.
"We don't know the function of half the genes we found in the organisms from these three phyla," says Banfield.
Read more at Science Daily
The cells have an average volume of 0.009 cubic microns (one micron is one millionth of a meter). About 150 of these bacteria could fit inside an Escherichia coli cell and more than 150,000 cells could fit onto the tip of a human hair.
The scientists report their findings Friday, Feb. 27, in the journal Nature Communications.
The diverse bacteria were found in groundwater and are thought to be quite common. They're also quite odd, which isn't a surprise given the cells are close to and in some cases smaller than several estimates for the lower size limit of life. This is the smallest a cell can be and still accommodate enough material to sustain life. The bacterial cells have densely packed spirals that are probably DNA, a very small number of ribosomes, hair-like appendages, and a stripped-down metabolism that likely requires them to rely on other bacteria for many of life's necessities.
The bacteria are from three microbial phyla that are poorly understood. Learning more about the organisms from these phyla could shed light on the role of microbes in the planet's climate, our food and water supply, and other key processes.
"These newly described ultra-small bacteria are an example of a subset of the microbial life on earth that we know almost nothing about," says Jill Banfield, a Senior Faculty Scientist in Berkeley Lab's Earth Sciences Division and a UC Berkeley professor in the departments of Earth and Planetary Science and Environmental Science, Policy and Management.
"They're enigmatic. These bacteria are detected in many environments and they probably play important roles in microbial communities and ecosystems. But we don't yet fully understand what these ultra-small bacteria do," says Banfield.
Banfield is a co-corresponding author of the Nature Communications paper with Birgit Luef, a former postdoctoral researcher in Banfield's group who is now at the Norwegian University of Science and Technology, Trondheim.
"There isn't a consensus over how small a free-living organism can be, and what the space optimization strategies may be for a cell at the lower size limit for life. Our research is a significant step in characterizing the size, shape, and internal structure of ultra-small cells," says Luef.
The scientists set out to study bacteria from phyla that lack cultivated representatives. Some of these bacteria have very small genomes, so the scientists surmised the bacteria themselves might also be very small.
To concentrate these cells in a sample, they filtered groundwater collected at Rifle, Colorado through successively smaller filters, down to 0.2 microns, which is the size used to sterilize water. The resulting samples were anything but sterile. They were enriched with incredibly tiny microbes, which were flash frozen to -272 degrees Celsius in a first-of-its-kind portable version of a device called a cryo plunger. This ensured the microbes weren't damaged in their journey from the field to the lab.
The frozen samples were transported to Berkeley Lab, where Luef, with the help of Luis Comolli of Berkeley Lab's Life Sciences Division, characterized the cells' size and internal structure using 2-D and 3-D cryogenic transmission electron microscopy. The images also revealed dividing cells, indicating the bacteria were healthy and not starved to an abnormally small size.
The bacteria's genomes were sequenced at the Joint Genome Institute, a DOE Office of Science User Facility located in Walnut Creek, California, under the guidance of Susannah Tringe. The genomes were about one million base pairs in length. In addition, metagenomic and other DNA-based analyses of the samples were conducted at UC Berkeley, which found a diverse range of bacteria from WWE3, OP11, and OD1 phyla.
This combination of innovative fieldwork and state-of-the-art microscopy and genomic analysis yielded the most complete description of ultra-small bacteria to date.
Among their findings: Some of the bacteria have thread-like appendages, called pili, which could serve as "life support" connections to other microbes. The genomic data indicates the bacteria lack many basic functions, so they likely rely on a community of microbes for critical resources.
The scientists also discovered just how much there is yet to learn about ultra-small life.
"We don't know the function of half the genes we found in the organisms from these three phyla," says Banfield.
Read more at Science Daily
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