May 21, 2016
Because Mars is directly opposite the sun (in relation to Earth) during opposition, Mars rises as the sun sets, and sets as the sun rises. This also means that Mars is visible all night long this weekend. To mark the occasion, NASA scientists used the Hubble Space Telescope to capture an absolutely stunning view of Mars as it nears opposition.
The exact time when Mars will be above the horizon depends on your location. For example, in New York, Mars rises in the East at 8:10 p.m. EDT and sets in the West at 5:35 a.m. EDT, so it is above the horizon for 9 hours and 25 minutes. Farther south, it will be visible longer, and farther north, for a shorter time.
The easiest way to spot Mars this weekend is to go out when the Red Planet is highest in the sky, close to midnight local time. Remember that if you live in a part of the world that is on daylight saving time, that “sweet spot” of viewing times will be close to 1 a.m. your local time.
If you live anywhere north of the equator, Mars will be due south at midnight local time. If you live south of the equator, Mars will be high overhead. On opposition night, Mars will be close to the nearly full moon, and will be the brightest object in the sky, except for the moon and Jupiter, over near the western horizon. Look for Saturn and the bright-red star Antares nearby.
What Mars looks like
The most striking thing about Mars’ appearance to the naked eye is its red color. This will be particularly clear if you compare it with Jupiter over in the west. They are almost equal in brightness, but Jupiter is a pale cream color, whereas Mars is noticeably red.
If you view Mars through a telescope, you are likely to be disappointed. All of the planets are much smaller than people expect, and this is particularly so with Mars, because it is one of the smallest planets in the solar system; only Mercury is smaller.
You may have heard an internet rumor that, on a particular date, Mars will appear as large as the moon. This is physically impossible, because Mars is always much farther away than the moon, and never appears larger than 1/70 ofthe diameter of the moon. On opposition night, Mars will be only 1/100 of the diameter of the moon. In other words, it will take a telescope magnifying 100 times to make Mars look as big as the moon as seen with the naked eye.
It takes a trained eye to see detail on a disk that small. Experienced planetary observers spend years sketching Mars at every opportunity, trying to catch the rare instants when Earth’s atmosphere steadies enough to reveal Mars’ secretive details. It takes patience and an optically excellent telescope.
Usually, Mars observers first look for the planet’s polar ice caps. However, this year, Mars is close to its equinox, so both polar caps are at their smallest, and thus hard to see. What may be visible is the pale haze that forms over the polar regions.
It is usually possible to see so-called albedo markings, variations of dark and light caused by the alternation of bedrock and desert sands. The darker areas appear grey-green, while the lighter areas are a pale peach color. The contrast between light and dark is very low but may be enhanced by using a red or orange filter.
Read more at Discovery News
Based on observations from the Kepler space telescope, a new study suggests yes. Perhaps Jupiter, Saturn, Uranus and Neptune were created close in to the sun. Over time, their gravities working together helped pull them away from the disc of gas and dust surrounding our sun. Once the giant planets cleared, this created room for the small planets living near the sun today: Mercury, Venus, Earth and Mars.
“Exactly how and where planets form is an outstanding question in planetary science,” said lead author Sean Mills, a graduate student in astronomy and astrophysics at the University of Chicago, in a statement. “Our work essentially tests a model for planet formation for a type of planet we don’t have in our solar system.”
There are differences from our own solar system, however. Kepler-223 is older (4.6 billion years) and so its planets have stayed in place much longer than ours, if they did migrate.
But there is something interesting about this system. The four planets are in resonance with each other, meaning that they orbit in a simple ratio to each other (such as 2 orbits for every 1). This is the first time four planets have been seen in resonance.
|Saturn’s moons Io, Europa and Ganymede are in resonance.|
So in our own solar system, perhaps the four gas giants were in resonance — but then were hurled into new orbits over time after hitting asteroids, planets in formation and other debris in the inner solar system.
Read more at Discovery News
May 20, 2016
In a roundtable discussion, published today, The Kavli Foundation spoke to two of the researchers behind the discovery about why the source of these heavy elements, collectively called "r-process" elements, has been so hard to crack.
"Understanding how heavy, r-process elements are formed is one of hardest problems in nuclear physics," said Anna Frebel, assistant professor in the Department of Physics at the Massachusetts Institute of Technology (MIT) and also a member of the MIT Kavli Institute for Astrophysics and Space Research (MKI).
"The production of these really heavy elements takes so much energy that it's nearly impossible to make them experimentally," Frebel continued. "The process for making them just doesn't work on Earth. So we have had to use the stars and the objects in the cosmos as our lab."
The findings also demonstrate how determining the contents of stars can shed light on the history of the galaxy hosting them. Nicknamed "stellar archaeology," this approach is increasingly allowing astrophysicists to learn more about conditions in the early universe.
"I really think these findings have opened a new door for studying galaxy formation with individual stars and to some extent individual elements," said Frebel. "We are seriously connecting the really small scales of stars with the really big scales of galaxies."
In the late 1950s, nuclear physicists had worked out that extreme conditions somewhere in the cosmos, full of subatomic particles called neutrons, must serve as the forges for r-process elements, which also include familiar substances such as uranium and lead. The explosions of giant stars and the rare mergings of the densest stars in the universe, called neutron stars, were the most plausible sources. But observational evidence was sorely lacking.
Researchers at the MKI have now filled this observational gap. An analysis of the starlight from several of the brightest stars in a tiny galaxy called Reticulum II, located some 100,000 light years from Earth, suggests these stars contain whopping amounts of r-process elements.
Since the stars could not have made the heavy elements on their own, some event in Reticulum II's past must have "seeded" and enriched the matter that grew into these stars. The abundances of elements in the stars squarely implicates the collision of two neutron stars.
Frebel's graduate student Alexander Ji discovered the enriched stars in Reticulum II while using the Magellan telescopes at the Las Campanas Observatory in Chile. He is first author on a paper about the findings, published March 31 in the journal Nature.
"When we read off the r-process content of that first star in our telescope, it just looked wrong, like it could not have come out of this galaxy!" said Ji, in the roundtable. "I spent a long time making sure the telescope was pointed at the right star."
Ji further commented on how the discovery helps to finally tell the tale of how r-process elements come to exist. "Definitely one of the things that I think attracts people to astronomy is understanding the origin of everything around us."
Read more at Science Daily
Now, new research has uncovered four genes that govern some of the variation in the human olfactory organ.
The new findings could help scientists understand the roots of this variation, the researchers said.
“Finding out the role each gene plays helps us to piece together the evolutionary path from Neanderthal to modern humans,” study co-author Kaustubh Adhikari, a cell and developmental biologist at University College London, said in a statement. “It brings us closer to understanding how genes influence the way we look, which is important for forensics applications.”
Although many people think of nose shape as a purely aesthetic feature, researchers suspect that different nose shapes evolved in different environments, for different reasons, the study authors said.
“For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate,” said study lead author Andrés Ruiz-Linares, a biologist at University College London. “Identifying genes affecting nose shape provides us with new tools to examine this question, as well as the evolution of the face in other species.”
To figure out what makes a nose, the researchers studied nearly 6,000 people from Colombia, Peru, Brazil, Chile and Mexico who had participated in the CANDELA study, an ongoing study of the biological diversity of people living in Latin America. The people in the study have a mix of Caucasian, African and Native American ancestry, creating a wide range of facial features. Past research from this population has identified genes that make people go gray.
The team analyzed the participants’ facial features, and also did 3D reconstructions for 3,000 of the participants, to get exact measurements of their facial features.
Read more at Discovery News
At home, we see mountains grow in ranges that can stretch across thousands of miles. But on Io, the more than 100 cataloged mountains mostly grow in isolation. What mysterious tectonic forces are at play here?
Io is so active that it’s hard to look at the tectonics from space; molten lava coats the surface at an incredible rate of five inches per decade. So to answer the question, a new study used simulations to figure things out.
|A close-up of Mongibello Mons at sunset. The mountain is about 8.6 kilometers (5 miles) high. Io has mountains that are as high as 10 miles above the plain, which is taller than Earth mountains.|
“All that lava spewed on the surfaces pushes downward and, as it descends, there’s a space problem because Io is a sphere, so you end up with compressive forces that increase with depth.”
The new work simulates this hypothesis, but focuses on the fact that Io’s compression gets stronger as you go deeper into the moon. This creates strain in a single fracture created deep inside of Io and then erupting to the surface, creating a cliff. The scientists also suggest this could explain why so many recent eruptions are found near the mountains.
|The south polar region of Io as seen by Voyager 1. This includes the mountain Haemus Mons, which is 10 kilometers (32,000 feet) high. It is visible at bottom.|
Read more at Discovery News
The collider, which is managed by the European Organization for Nuclear Research (CERN) is located near Geneva, Switzerland.
With the countless billions of collisions between ions inside the LHC’s detectors comes a firehose of data that needs to be recorded, deciphered and stored. Since the 27 kilometer (17 mile) circumference ring of supercooled electromagnets started smashing protons together once more after its winter break, LHC scientists are expecting a lot more data this year than what the experiment produced in 2015.
“The LHC is running extremely well,” said CERN Director for Accelerators and Technology Frédérick Bordry in a statement. “We now have an ambitious goal for 2016, as we plan to deliver around six times more data than in 2015.”
And this data will contain ever more detailed information about the elusive Higgs boson that was discovered in 2012 and possibly even details of “new” or “exotic” physics that physicists could spend decades trying to understand. Key to the LHC’s aims is to attempt to understand what dark matter is and why the universe is composed of matter and not antimatter.
In fact, there was already a buzz surrounding an unexpected signal that was recorded in 2015 that could represent something amazing, but as is the mantra of any scientist: more data is needed. And it looks like LHC physicists are about to be flooded with the stuff.
Central to the LHC’s recent upgrades is the sheer density of accelerated “beams” of protons that are accelerated to close to the speed of light. The more concentrated or focused the beams, the more collisions can be achieved. More collisions means more data and the more likelihood of revealing new and exciting things about our universe. This year, LHC engineers hope to magnetically squeeze the beams of protons when they collide inside the detectors, generating up to one billion proton collisions per second.
Add these advances in extreme beam control with the fact the LHC will be running at a record-breaking collision energy of 13 TeV and we have the unprecedented opportunity to make some groundbreaking discoveries.
“In 2015, we opened the doors to a completely new landscape with unprecedented energy. Now we can begin to explore this landscape in depth,” said CERN Director for Research and Computing, Eckhard Elsen.
Read more at Discovery News
May 19, 2016
Those were the questions underpinning a new study out of North Carolina State University just published in the Journal of Urban Ecology.
To get some answers, N.C. State researchers gathered worker honey bees from colonies in both urban and rural areas within 30 miles of Raleigh, N.C. All told, they collected bees from 39 colonies – 24 run by beekeepers and 15 that were wild.
To gauge how much of the bees’ diet came from processed sugars vs. flower nectar, the scientists studied them for their levels of carbon-13, an isotope whose presence in their bodies would indicate how much human food each bee was taking in.
It turned out that the scientists were in for a surprise.
The researchers say they turned up no evidence that urban bees had consumed more processed sugar than their rural counterparts.
“Basically, bees are relying on flowers in cities and are not turning to human foods to supplement their diet,” Clint Penick, lead author of the study, said in a statement.
“This is good news for urban beekeepers,” he said. “The honey in their hives is mostly coming from flower nectar and not old soda, which is what we originally guessed.”
The finding, the research team wrote, “suggests an important role for urban flowers and green spaces in maintaining healthy pollinator populations in cities.”
Penick said further study would be needed to test if their results would apply to cities much larger than Raleigh, which is mid-sized, at just under 440,000 residents.
From Discovery News
The bees from the genus Euglossa formulate their unique perfumes for reasons similar to ours: to attract mates, establish a signature identity, and smell good in a crowd. They do this by gathering a variety of carefully selected scents from their environment, and then douse their bodies with the perfume.
“The males expose them at the places where mating occurs,” said co-author Thomas Eltz of Ruhr-University Bochum, “so the perfumes may be chemical signals to females.”
For the study, published in the Journal of Experimental Biology, Eltz and his colleagues collected several species of orchid bees during a trip to Panama. They enticed the bees with scents such as vanilla and cinnamon, applied to strips of filter paper that were attached to trees.
“It is quite a spectacular sight to have dozens of green, blue or red metallic bees appear out of nowhere around a bait,” Eltz said.
The researchers next analyzed the scents blended by males and also studied how the bees responded when presented with various fragrances.
Some of the bee-made scents turned out to be unique compounds that are not even commercially available to human shoppers. Co-author Erik Hedenström recreated one of them in the lab: 6-(4- methylpent-3-enyl)-naphtalene-1,4-dione.
When comparing how orchid bee species reacted to multiple fragrances, the scientists determined that the most closely related bee species had similar sensitivity to odor. Conversely, distantly related species showed the greatest differences.
This means that, instead of evolving dramatically different senses of smell to accompany their individual scents, the bees’ senses of smell had diverged more gradually over time.
Read more at Discovery News
On his Indiegogo campaign Salo writes:
“Many people want to know more about 9-11. We are like a Mythbusters for September 11th. It’s an important project for many reasons. Many people doubt various details of 9-11. As the world has changed our trust in government and media has declined significantly. We want to see for ourselves. We don’t need people to guide our thinking. In this project we will recreate 9-11 to the best of our ability given the funds raised. Our ultimate goal is a fully loaded 767 and a similar structure to the WTC. We will crash the fully loaded (with fuel) plane (complete with black box) into the building using autopilot at 500 MPH.”Salo aims to test the widely challenged (in conspiracy circles anyway) claim that jet fuel can burn hot enough to sufficiently weaken a building’s steel structure that it collapses -- instead of, for example, the Twin Towers coming down due to hidden explosives. Some people believe the project to be in bad taste, while others see it as a legitimate grassroots effort to get at a truth long covered up by the government.
Science and Anomaly Hunting
Conspiracy theorists thrive on what is known as anomaly hunting: Looking for any evidence that doesn’t fit the “official story.” For example: In the confusion after a mass shooting, if police or eyewitnesses report details incorrectly -- perhaps mistaking a car backfire for a gunshot -- this provides grist for the conspiracy mill, “evidence” that a cover up is in effect.
To see the problem that anomaly hunting poses, consider the following example. A college student reads that water freezes at 32 degrees Fahrenheit. Being a naturally inquisitive person, he decides to try it for himself. The student fills a cup with water and puts it, along with a thermometer, in a freezer and sets the freezer’s temperature. The next day he opens the freezer door and finds that the water is very cold but not frozen. This information -- this anomaly -- contradicts widely accepted knowledge about the freezing temperature of water. The thermometer reads below 32 degrees, yet the water is not frozen.
What the student perceives as an anomaly is in fact nothing of the sort. The error is not with accepted science, but with his procedures or understanding of the phenomenon.
But before he concludes that “the official story” is wrong and he’s disproven basic physics, he should read the fine print for a better understanding of what he was looking for. Pure water freezes at 32 degrees Fahrenheit at sea level. If the water was not pure, or if the thermometer was not exact enough for scientific purposes, or if he’s not at sea level, or if there was a bit of oil or another contaminant in the cup -- or any number of other factors he didn’t think of -- then he will not necessarily get an accurate reading or the expected result.
The idea of replicating a controversial event or project to test its validity sounds simple in theory. For example some people claim that the Egyptian pyramids were made -- or designed -- by aliens or ancient astronauts. The (ahistorical) assumption is that people at the time didn’t have the intelligence or technology to move the stones and build a pyramid shape.
Since the pyramids were built around 2560 B.C. there are no photographs or depictions of them being created, though in 2015 papyrus records were found of pyramid construction tools.
Egyptologists have a pretty good idea of where the rocks were quarried and how they were cut and moved, but doubters are fond of noting that scientists have never actually replicated the pyramids. They claim that skeptics or scientists must build an entire pyramid to prove how it could have been done, using materials and tools of that era.
This seems like a reasonable challenge until you realize that such an effort would never be done -- not because it can’t be done but because it would be impractical. Duplicating the great Ghiza pyramid would take many years and cost tens of millions of dollars. Who’s going to pay for it? It would also be pointless, since such a replication experiment would not be valid unless you used tens of thousands of workers -- estimates range from 15,000 to 40,000 -- and spent a decade or more building it, as the original did.
If some eccentric billionaire wants to fund it he or she should feel free, but scientists recognize it as an enormous cost and effort just to disprove some wild theories about aliens.
Thus while Salo’s scheme to duplicate the Twin Towers attack has a simple and populist appeal, actually pulling it off as a valid scientific experiment would be incredibly difficult and expensive, if not impossible. For a real science experiment you need to control for variables that could affect the results; in this case there are many variables including size and weight of the plane, the building type, and so on.
Salo writes that “You will be able to see for yourself what happens under these extreme circumstances. I’m not sure (from) which country we will purchase the aircraft and building but it doesn’t really matter much.” Actually Salo will find when talking to engineers that it matters greatly where the building is, since building codes vary wildly by country and region.
Buildings in earthquake-prone regions are built differently -- and able to sustain greater structural damage without collapsing -- than those built elsewhere. Variations in construction materials will also complicate comparisons.
Salo has another problem: Each building’s architecture is different, and will not necessarily react the same way to the same structural damage. In order for the experiment to be valid, he would need to build an exact replica of the Twin Towers; not just any tall building will do, since the load-bearing structures vary from building to building.
Despite his enthusiasm, Salo, like the public generally, greatly underestimates the rigor needed to conduct a valid scientific experiment. He says he plans to “recreate as best as we can” the circumstances of the World Trade Center attacks.
The problem is that “as best as we can” will leave an enormous margin of error, one so big as to make any results invalid and pointless. His results, should he pull it off, will be dramatic and sensational but hold no evidentiary value at all. He wouldn’t be comparing apples to apples -- or even apples to oranges -- but apples to astronauts.
Read more at Discovery News
The findings, published in the journal Scientific Reports, help to explain why native North Africans today are genetically related to people from Europe and Asia, in addition to other Africans. It also offers strong evidence that "Out of Africa" was not a one-way trip for some human lineages that traveled back to North Africa starting around 45,000 years ago.
At the center of it all is a prehistoric individual named the Pestera Muierii Woman, or PM-1 for short. Her skull, dated to 35,000 years ago, was unearthed in the Pestera Muierii cave of Romania.
Her "mosaic of modern human and archaic Neanderthal morphological (physical) features may be the result of Neanderthal interbreeding," senior author Concepcion de-la-Rúa of the University of the Basque Country's Department of Genetics told Discovery News.
de-la-Rúa and her colleagues extracted DNA from two of the woman's teeth and determined the ancient female's mitochondrial genome (mitogenome), i.e., a complete set of particular genes that are passed down from mothers to their daughters. The researchers noted that one component of this set, named "U6 basal," had not previously been identified in any ancient or existent humans.
Investigating the U6 mystery further, the scientists discovered that an evolved version of U6 does indeed exist today.
"U6 is found predominantly in present-day North African populations," de-la-Rúa said, adding that the form in Pestera Muierii Woman dates to a much earlier time and therefore is "basal," or at the root of U6's emergence.
Putting the clues together, the researchers believe that the woman's Homo sapiens ancestors migrated out of Africa and, at some point, mated with one or more Neanderthals, since she appears to have been part Neanderthal. This is actually true of all people of Asian and European heritage today, who retain Neanderthal DNA in their genomes.
The woman then "represents an offshoot to South-East Europe, i.e. Romania, of this back migration starting in the Early Upper Paleolithic period about 40–45,000 years ago," de-la-Rúa said.
As for why Romanians today do not have U6 basal, the researchers think this early form of U6 could have gone extinct hundreds or even thousands of years after the woman lived. de-la-Rúa explained that "mitochondrial lineages may disappear when a woman does not have children or if she only has male descendants."
The "Out of Africa" migrants clearly went to a lot of trouble to travel to Asia and then to Europe, so why would many of their not-too-distant later relatives have been so eager to return to Africa? The researchers offered a two-word answer: a "difficult climate."
De-la-Rúa explained that "between 50,000–20,000 years ago, it was (often) very cold due to climatic fluctuations" in Europe.
Vicente Cabrera, professor at the University of La Laguna in Tenerife, Spain, said that "a migration from Eurasia is the best explanation for the radiation of U6 in Africa."
Read more at Discovery News
Although Mars and Earth’s orbits are approximately circular around the sun, they are slightly elongated, meaning that both planets drift closer to the sun at certain times. Should Mars be a little closer to the sun during opposition, the Mars-Earth distance will be even smaller.
Earth orbits the sun every 365 days; Mars orbits the sun once every 687 Earth days.
Opposition occurs once every 26 months or so, but on May 22, the two planets will come within 0.503 AU (or 46.78 million miles) of each other, making this the closest opposition for 10 years. The closest opposition in recorded history occurred in 2003 when Mars came within 34.65 million miles from Earth.
Of course, this celestial alignment produces a rare opportunity for Earth-bound astronomers. When Mars is at opposition, we can see the planet appear brighter in the night sky as it is located in an anti-sunward direction. And, as if peeking over the interplanetary fence, Hubble took the opportunity to see Mars’ full frontal, giving us a global view of a completely sun-lit hemisphere.
Captured in this observation are some famous features, including Hellas Basin, Schiaparelii and Hugens craters, plus the cratered Arabia Terra and the north polar icecap:
Read more at Discovery News
May 18, 2016
The discoveries increase the known diversity of ceratopsians, which were plant-eating horned dinos that roamed North America and Asia during the final stages of the age of dinosaurs.
One of the new dinosaurs, Machairoceratops cronusi, lived 77 million years ago at what is now called the Grand Staircase-Escalante National Monument of southern Utah. This was during a time when North America was subdivided by a sea into western (Laramidia) and eastern (Appalachia) landmasses.
Machairoceratops measured about 26 feet long and weighed as much as 4409 pounds. Lead author and Ohio University graduate student Eric Lund told Discovery News that the dinosaur possessed “two large, forward curving spikes off of the back of the neck shield, each of which is marked by a peculiar groove extending from the base of the spike to the tip.”
The neck shield, also called a “frill” since the bony mass has a decorative nature, was “probably utilized during within species interactions including sexual display and mate competition,” Lund said. He added, “The spikes probably also functioned in a between species aspect for species recognition allowing (dinosaurs of the same species) to recognize one another. The function and purpose of the unique groove marking the posterior margin of the spikes is totally unknown as this is a character not observed in any other horned dinosaur.”
The discovery of Machairoceratops strengthens the idea that ceratopsians occupied two distinct regions that were separated within Laramidia, and suggests that different evolutionary pressures acted upon the groups during the late Cretaceous. Although many fossils of this dino group have been discovered in what were once northern regions of Laramidia (Alaska, Alberta, Montana, and Saskatchewan), relatively few have been recovered from the southern portion (Utah, Colorado, New Mexico, Texas, and Mexico) of the ancient continent.
“An effort like this underscores both the necessity and excitement of basic, exploratory science in order to better understand the history of the world around us,” noted study co-author Patrick O’Connor, who is a professor of anatomical sciences at the Heritage College of Osteopathic Medicine. “Even in a place like western North America, where intense work has been conducted over the past 150 years, we are still finding species new to science,” he added.
The other new horned dinosaur with neck spikes was found in Montana a decade ago, but was only recently studied and identified. It has been named Spiclypeus shipporum, meaning “spiked shield.” The name “shipporum” honors the Shipp family on whose land the fossil was found near Winifred, Montana, by retired nuclear physicist Bill Shipp, who is now a fossil enthusiast.
The dino has a nickname too — Judith — after the Judith River geological formation where it was found.
Read more at Discovery News
The eight-page letter was penned by Columbus on Feb. 15, 1493 from his ship, the Niña, on his way back to Spain after the historic voyage to the Americas.
Addressed to King Ferdinand and Queen Isabella, it described Columbus’ impressions about the people, flora and fauna of the Americas. The manuscript was translated into Latin, printed and distributed around Europe to spread the news of Spain’s findings in the new world.
Only a handful of these copies have survived. One of them, bound in a volume and printed by Stephan Plannck — known as the Plannck II Columbus letter — was kept at Florence’s Riccardiana library.
The volume was stolen from the Florentine library at least 24 years ago, but the theft was discovered only in 2012. The thieves had replaced it with a forged copy. According to the director of the library, it is also possible the theft and substitution occurred in 1950-51 while the book was out on loan.
In 2012, Homeland Security Investigations (HSI) special agents received a tip that the Plannck II letter in the Riccardiana Library had been replaced with a forgery and informed Italy’s Carabinieri art squad.
A rough binding, the print style and the different page size clearly showed it was a forgery.
Detective work revealed the stolen volume, which had the Riccardiana Library’s stamp removed, was bought by a private collector at auction in 1992 for $300,000. It was finally bequeathed to the Library of Congress in Washington in 2004.
According to a statement of the Carabinieri art squad, the true value of the letter is estimated at 1 million euros ($1.13 million).
Read more at Discovery News
Andrew Glikson, from the Australian National University’s Planetary Institute, said that while the asteroid would have been massive, the exact location of where it hit was not known.
“The impact would have triggered earthquakes orders of magnitude greater than terrestrial earthquakes, it would have caused huge tsunamis and would have made cliffs crumble,” he said in a statement.
“Material from the impact would have spread worldwide.”
Speaking to AFP on Wednesday, Glikson said he and Arthur Hickman from the Geological Survey of Western Australia had found tiny glass beads called spherules, which are formed by vaporized material from an asteroid’s impact, in Australia’s remote northwest.
They were discovered in a sediment layer originally on the ocean floor and which had been preserved between two volcanic layers. It dates from 3.46 billion years ago.
“It is the second oldest known,” Glikson said of the asteroid, which was estimated to have been at least 20 kilometers (12 miles) across and to have created a crater hundreds of kilometers wide.
This makes it larger than the giant asteroid that collided with Earth some 66 million years ago and is widely blamed for the demise of the dinosaurs. That asteroid is estimated to have measured around 15 kilometers wide.
Tests on the beads found in Western Australia found levels of elements such as platinum, nickel and chromium corresponding with those found in asteroids, according to the scientists’ paper in Precambrian Research.
Glikson said while the find was evidence of the second oldest asteroid to hit Earth, there may have been other similar impacts that have yet to be discovered because asteroid craters from the period have been obliterated by volcanic activity and tectonic movements.
Read more at Discovery News
This moon is thought to be awash with a subsurface ocean protected from space radiation by a thick shell of ice. The ocean is also believed to be salty, containing much of the same chemicals that facilitated life on Earth. Some hypotheses even suggest there’s enough oxygen and nutrients cycling through the water to support not only microbial life, but also multi-cellular life.
But how Earth-like is Europa’s ocean? Could it truly be a biological oasis in orbit around the most massive planet in the solar system?
In new research published in the journal Geophysical Research Letters, NASA scientists studied how the chemical composition of the Europan ocean may have evolved and what chemicals it possibly contains, assuming similar geochemical processes as on Earth are at play.
“We’re studying an alien ocean using methods developed to understand the movement of energy and nutrients in Earth’s own systems,” said planetary scientist Steve Vance, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The cycling of oxygen and hydrogen in Europa’s ocean will be a major driver for Europa’s ocean chemistry and any life there, just it is on Earth.”
Europa is thought to possess a rocky core fractured with deep cracks that have filled with water. Since the formation of the moon, the core has continued to cool, creating more cracks and exposing more rocks to chemical processes with this water.
On Earth, interactions between water and minerals in rock is called serpentization; a reaction that forms new minerals, releasing copious quantities of hydrogen in the process. As more cracks form over the billions of years since formation, more reactions can take place, loading the salty water with hydrogen. This is the first half of Europa’s life-giving equation.
Assuming Europa has these complex geochemical processes, for life to be a possibility there needs to be some kind of oxidizing agent injected into the ocean to undergo key chemical reactions with all this hydrogen fizzing from below. And it just so happens that the surface of Europa may be the ideal supplier. As the intense radiation surrounding Jupiter continuously barrages the icy surface, the chemical bonds of water ice are broken to produce an oxididant factory. Oxidants are molecules of oxygen atoms that combine with other chemicals.
It is well known that Europa has a fractured surface that is constantly renewed. The lack of impact craters proves that some form of icy tectonic activity is constantly rejuvenating the surface allowing these oxidants to be dissolved into the ocean below.
“The oxidants from the ice are like the positive terminal of a battery, and the chemicals from the seafloor, called reductants, are like the negative terminal,” said planetary scientist Kevin Hand, also from JPL. “Whether or not life and biological processes complete the circuit is part of what motivates our exploration of Europa.”
These chemical processes do not require any form of volcanic activity to help the reactions along — in fact, the serpentization reactions with the rocky core could be perfect for a surprisingly Earth-like chemistry.
“… if the rock is cold, it’s easier to fracture,” said Vance. “This allows for a huge amount of hydrogen to be produced by serpentinization that would balance the oxidants in a ratio comparable to that in Earth’s oceans.”
Read more at Discovery News
May 17, 2016
The tourists loaded the animal into their trunk last week and drove it to a ranger station after taking a photograph that prompted a backlash on social media.
The newborn had to be euthanized because its mother had rejected it as a result of “interference by people,” officials said.
“In this case, park rangers tried repeatedly to reunite the newborn bison calf with the herd. These efforts failed,” the park said in a statement on its website.
“The bison calf was later euthanized because it was abandoned and causing a dangerous situation by continually approaching people and cars along the roadway.”
The park berated visitors for taking selfies and recording video near the bison, flouting regulations demanding people stay at least 25 yards (23 meters) away.
“In a recent viral video, a visitor approached within an arm’s length of an adult bison in the Old Faithful area,” it said of the park’s famous geyser. “Another video featured visitors posing for pictures with bison at extremely unsafe and illegal distances.”
Five visitors were seriously injured last year after approaching bison too closely, the park said.
In the latest incident, a father and son transported the bison calf in their Toyota Sequoia to a ranger station in the park’s northeast corner, a witness told the online East Idaho News.
“They were demanding to speak with a ranger. They were seriously worried that the calf was freezing and dying,” said Karen Richardson, one of several parents chaperoning a group of fifth-graders on a field trip.
The website quoted another parent who told the tourists to remove the bison from their car, warning they could be in trouble.
Read more at Discovery News
“Bird whistles were children’s toys, but in this context may have been used for sound effects in theatrical performances,” the Museum of London Archaeology (MOLA) wrote in a statement.
In Shakespeare’s Romeo and Juliet there are several references to bird song, such as “That birds would sing and think it were not night.”
Found in 2011 behind a pub in Shoreditch, east London, the remains of the Curtain have revealed other intriguing findings.
According to MOLA archaeologists, the playhouse, which opened in 1577, was rectangular — not round or polygonal like most Elizabethan theaters.
They found wall remains up to five feet high, revealing the venue measured some 72 feet by 100 feet and could hold about 1,000 people.
“Our archaeologists have been able to identify the courtyard, where theatregoers stood, and the inner walls, which held the galleries where wealthier audience members would have sat,” MOLA said.
Built some 200 yards south of The Theater, London’s first playhouse which had opened a year before, The Curtain was believed to have staged the premier of Shakespeare’s Henry V.
However, in the opening verses of the play, the playhouse is described as “this wooden O.”
Read more at Discovery News
The so-called Heckelman site, located near the town of Milan, in Ohio’s Erie County, is on a flat-topped bluff above the Huron River. There, people of the “Early Woodland” period of North American prehistory erected tall, freestanding wooden poles as part of the group’s social or religious ceremonies.
Archaeologist Brian Redmond, a curator at the Cleveland Museum of Natural History, said the location of the site appeared to echo a conception of the cosmos common to many Native American peoples.
“We know that Native American and many different tribal groups had a very specific vision about the world as a three-layered cosmos: the upper world, the middle world that we live on and an underworld,” Redmond, author of a new research paper on the earliest occupants of the Heckelman site, told Live Science.
The site is bordered by water, which ancient people could have seen as symbolic of the underworld, Redmond said. The wooden poles on the bluff may have been constructed to reach up to the sky, in the direction of the upper world, he added.
“So this could have been seen as a spiritually powerful landscape where you connected the three worlds together, with the poles as an ‘axis mundi’ (axis of the world) or ‘tree of life’ type of thing, which is global in the way that cultures looked at these things,” Redmond said.
The Heckelman site is unique among Early Woodland sites in the region because there are no signs of human burials or preparations for burials, Redmond said. Instead, the site seems to have been used for rituals or festivals associated with the living, rather than the dead, he said.
“From everything we’re seeing, we’re very certain it was some sort of ceremonial location. The fact we found no human burials, we found no evidence of mortuary treatment or mortuary ceremonialism — this site really stands out because we really didn’t find any direct evidence of that,” Redmond said. “So it’s a different kind of ceremonialism, a ritualism related to the living — it represents that these people had a rich ceremonial life, a religious life, that wasn’t just involved in burying people.”
The unusual site features two parallel ditches that enclose the top of the bluff, and an oval ditch that encloses a flat area measuring about 87,000 square feet (8,080 square meters), where the wooden poles were erected.
None of the poles remain, but their locations can be determined by what’s left of the “post molds,” or pits, that were dug to hold the poles upright, researchers said. Judging by the size of the holes, the poles would have stood about 10 to 12 feet (3 to 3.7 m) tall, the researchers said.
“Unlike other sites where we have post molds, these don’t represent the walls of a structure or a specific building. They seem to be freestanding, upright poles, which would indicate they had some different kind of function,” Redmond said. “When I was looking at all the data and maps of the distribution of these poles, it’s kind of a habit to try to make them into a structure, to look for rectangles or circles or something like a building, and I was really frustrated by the fact that I couldn’t do that in the end. And then I realized, these are something else.”
About six clusters of poles have been identified at the site so far. Each cluster may have been part of ceremonies held at the site at different times or by different groups of people, Redmond said.
“It really is very different than we’ve seen before,” he added. “You do see poles in some Adena sites in southern Ohio, such as the circular arrangements of posts called a ‘woodhenge‘ — sometimes these are found beneath Adena burial mounds. But that sort of regular pattern is something we’re not seeing up here.”
The Heckelman site, named after its private landowners, has been known since the 1950s, thanks to a large number of prehistoric artifacts found there by the landowners and amateur archaeologists. Those objects included pottery, spear points and knife blades.
Excavations in the 1960s and 1970s found one of the parallel ditches on one side of the bluff top, and a geomagnetic survey in 2008 revealed the second ditch and oval enclosure.
Archeologists from the Cleveland Museum of Natural History and the Firelands Archaeological Research Center, in Amherst, Ohio, excavated parts of the site each summer from 2009 to 2014.
In addition to evidence of the freestanding poles, researchers found pits filled with pottery shards and burned rocks, which were likely the remnants of food that had been prepared as part of the ceremonies at the site, Redmond said.
“With analogy to historic Native American groups and others, it seems like these ceremonies would have also involved preparing food and communal meals, or feasting,” he said.
The Early Woodland people were hunter-gatherers who lived in communities of a few families, and many of these groups likely used the Heckelman site, Redmond said.
“Their habitations were based on small groups of related families, but they did congregate in much larger groups for rituals or seasonal festivals,” Redmond said. “It was probably a very social thing. They would come together to exchange information, to talk about where to get the best flint, or where did you see geese or ducks last season?”
And there may have been other social benefits, too, he said.
“They needed to interact, to get together and develop their social organizations and relationships, and these places were probably used for that,” Redmond said. “So it is probably social , not just religion, going on at these places.”
Redmond said the discoveries at the Heckelman site underline the importance of preserving archaeological resources in the United States. In many cases, doing so depends on the help of private landowners, he said.
Read more at Discovery News
|The Belt of Venus occurs in the anti-sunward direction just after sunset and, depending on atmospheric conditions, a very dark band (the Earth's shadow) and an orange/pink glow (backscattered sunlight) can become very obvious.|
The “Belt of Venus” occurs just after sunset on cloudless evenings and, depending on atmospheric conditions, a reddish glowing band may appear in the anti-sunward direction. The glow itself is caused by back-scattered sunlight bouncing off dust particles suspended high in the atmosphere. Below the diffuse glow is the Earth’s shadow above the horizon. To observe it, you just need to have the setting sun at your back and face the opposite direction as sunset ends and dusk commences.
|The domes of the four main telescopes and four auxiliary telescopes of the Very Large Telescope commence opening ahead of a night's observing on May 9 during the #MeetESO social media event. Click for high-resolution version.|
The VLT is one of the most complex and advanced optical telescopes on the planet. Composed of 4 primary telescopes and 4 “auxiliary” 1.8 meter telescopes, the entire system can work as individual telescopes or in groups as the VLT Interferometer (VLTI). Interferometers use multiple telescopes to combine their observing power, mimicking a single, larger telescope. And on Paranal, the VLTI (including the VLT Survey Telescope) sit atop a huge concrete platform under some of the clearest skies on the planet.
|One of the VLT's auxiliary telescope domes open after sunset, with the fading Band of Venus above.|
Read more at Discovery News
May 16, 2016
Early results from an ongoing, five-year study in Maine and New Hampshire show that more and more moose are dying from rampant tick infestations. Tracking collars placed on 36 calves in New Hampshire show nearly 75 percent of the collared moose calves died from ticks.
It’s the second year in a row that the study has shown a decline in New Hampshire moose numbers due to ticks.
“It doesn’t bode well for moose in the long term if we continue to have these short winters,” Moose biologist Kristine Rines told the Portland Press Herald.
Shorter, milder winters favor winter ticks, which pile atop high plants in grotesque masses in November and wait for a moose to pass by. When the animal does walk by, the ticks latch on by the hundreds and begin a long winter feeding off the large mammal. One moose can host up to 75,000 ticks on its body.
By spring the moose have become so weakened and emaciated, many die. The ticks, meanwhile, finally drop off. Normally they would land on snow and cold conditions and then die. But shorter winters due to climate change mean they can drop off their hosts and hit bare ground – and live on to suck the life out of more hosts.
Average annual maximum temperatures in New Hampshire have warmed 0.5 to 2.1 degrees Fahrenheit since 1970, according to a 2014 report. During the 20th century, Maine warmed by 3 degrees Fahrenheit, and “the warm season increased by two weeks,” according to Maine’s Climate Future, a 2015 update by the University of Maine.
Milder winters favor ticks’ survival – as well as the survival of other pests, such as lungworm, which also take their toll on moose. While the results have shown an overall decline in moose numbers since the study began in 2014, last year Maine’s moose actually fared somewhat better. Moose calf mortality dropped last year from 73 to 60 percent.
Part of that interruption in moose calf mortality might be linked to declining numbers of moose – since ticks depend on the animals for survival.
Read more at Discovery News
The population has dramatically dropped despite the arrival of navy reinforcements in the upper Gulf of California in April 2015 to enforce a ban on fishing gillnets blamed for the vaquita’s death.
The porpoise’s population had already fallen to fewer than 100 in 2014, down from 200 in 2012, according to the International Committee for the Recovery of the Vaquita (CIRVA), a global group of scientists.
Mexico’s environment ministry said in a statement that a joint census conduct with CIRVA, undertaken with acoustic and visual studies, between September and December estimated the latest population at “around 60.”
“The vaquita is at the edge of extinction,” the World Wildlife Fund said in a statement, warning that 20 percent more have probably died in nets since January.
The vaquita’s fate has been linked to another critically endangered sea creature, the totoaba, a fish that has been illegally caught for its swim bladder, which is dried and sold on the black market in China.
Poachers use illegal gillnets to catch the totoaba and the vaquita, a shy 1.5-meter-long (five-foot) cetacean with dark rings are the eyes, is believed to be the victims of bycatch.
President Enrique Pena Nieto imposed a two-year ban on gillnets in April 2015 and increased the vaquita protection area tenfold to 13,000 square kilometers (5,000 square miles).
He deployed a navy patrol ship with a helipad, a dozen high-speed boats and two planes to enforce the prohibition.
Environment Minister Rafael Pacchiano said three vaquitas had been found dead and that protective measures needed to be reinforced, but federal authorities are convinced that the vaquita can still be saved.
He urged the local population to report illegal activities.
The Mexican government agreed to compensate local fishermen in a $30 million a year program to give up gillnet fishing while they look for safer alternative nets.
But navy sailors told AFP last month that they were catching gillnets every day — three to 10 times the length of a football field, often ensnaring totoabas, dolphins and turtles.
Captain Oona Isabelle Layolle, of the Sea Shepherd Conservation Society, said fishermen are still sneaking out at night to cast their nets.
Sea Shepherd, which has sent two boats to the region to help authorities catch gillnets, proposed to officials on Friday that the gillnet ban become permanent, Layolle told AFP.
Increasing the population is challenging because a mature female vaquita only gives birth once every two years, she said.
“There’s still hope,” she said.
The environment ministry said 600 nets were seized in the past year, while 77 people were detained.
Officials say fishermen sell the totoaba’s swim bladders to smugglers who store them in border towns before sending them to the United States or shipping them directly to Asia in suitcases or through parcel services.
Each bladder fetches around $1,500-$1,800 in Mexico, rising to $5,000 in the United States and $10,000 to $20,000 apiece in Asia, according to US authorities.
Consumed in soup, maw is believed to cure a host of ailments, from arthritis to discomfort in pregnancy, and plump up skin due to its high collagen content.
Read more at Discovery News
The discovery, hailed as the largest assemblage of marine artifacts recovered in the country during the past 30 years, was initially made by two divers who stumbled across the remains of a large merchant ship. It is estimated the vessel sank during the Late Roman period some 1,600 years ago.
Prompted by the divers’ report, IAA archaeologists cleared an extensive portion of the seabed, bringing to light iron anchors, coins and spectacular bronze statues.
“The sand protected them. They are in an amazing state of preservation – as though they were cast yesterday rather than 1,600 years ago,” Jacob Sharvit, director of the IAA marine archaeology unit and Dror Planer, deputy director of the unit, said in a statement.
The artworks include a bronze lamp depicting the image of the Roman sun god Sol, a figurine of the moon goddess Luna, a lamp in the shape of the head of an African slave, fragments of three life-size bronze cast statues, and objects fashioned in the shape of animals.
In addition, the archaeologists recovered fragments of large jars that were used by the crew for carrying drinking water and two metallic lumps. Surprisingly, the lumps were made of thousands of coins and shaped in the form of the pottery vessel in which they were transported.
“These are extremely exciting finds, which apart from their extraordinary beauty, are of historical significance,” Sharvit and Planer said.
The coins bear the likeness of two emperors: Constantine and Licinius. While Constantine ruled the Western Roman Empire (312–324 AD) and was later known as Constantine the Great, ruler of the Roman Empire(324–337 AD), Licinius ruled the eastern part of the Roman Empire.
A rival of Constantine, with whom he co-authored the edict that established religious toleration for Christianity within the Roman Empire, Licinius was submitted to Constantine following the Battle of Chrysopolis, in modern Turkey, in 324 AD.
According to Sharvit and Planer, the location and distribution of the artifacts on the seabed indicate that a large merchant ship was carrying a cargo of metal slated recycling.
“Because the statues were wrecked together with the ship, they sank in the water and were thus saved from the recycling process,” they said.
The archaeologists believe the ship encountered a storm at the entrance to the harbor and drifted until it smashed into the seawall and the rocks.
Read more at Discovery News
Drivers in the study were able to stay in their lanes when researchers distracted the participants with challenging questions, the researchers said. This likely happens because the brain subconsciously corrects for any mistakes that are made, the researchers said.
But when the drivers were asked to text while behind the wheel, they tended to drift between lanes, said the study, published today (May 12) in the journal Scientific Reports. The work was led by researchers at the University of Houston and the Texas A&M Transportation Institute, and was funded in part by the Toyota Class Action Settlement Safety Research and Education Program.
Normally, “the driver’s mind can wander, and his or her feelings may boil, but a sixth sense keeps a person safe, at least in terms of veering off course,” Ioannis Pavlidis, a professor of computer science at the University of Houston and the lead author of the study, said in a statement.
“What makes texting so dangerous is that it wreaks havoc into this sixth sense,” Pavlidis said.
In the study, 59 participants were asked to drive, in a driving simulator, down a challenging stretch of virtual highway under normal, nonstressful conditions. Then, the participants drove the same stretch under three different stressful conditions: cognitive stress, during which the driver was asked mathematical or analytical questions; emotional stress, during which the driver was asked “emotionally stirring” questions; and “sensorimotor” stress, “where the driver needs to move [his or her] eyes and one hand between the car’s controls and the smartphone all the time.” In this study, the sensorimotor stressor was texting.
The researchers measured every driver’s biological stress response during each condition by looking at how much the driver was sweating around the nose. They also measured how many times the driver drifted into another lane.
In all of the stressful situations, the drivers’ stress levels went up, the researchers found. In addition, the increased stress levels were associated with jittery handling of the steering wheel, which could result in drivers drifting into other lanes, the study said.
However, when drivers were challenged cognitively or emotionally, they were able to correct for these “jitters” and stay in their lanes, the researchers found. It was only when the drivers’ hand-eye coordination was disrupted, such as while texting, that they drifted into other lanes, the study said.
The “sixth sense,” or the ability of drivers to correct their driving mistakes, may come from the part of the brain called the anterior cingulate cortex, the researchers wrote.
This part of the brain “is known to automatically intervene as an error corrector” when there is a problem, Pavlidis said. For example, if a jittery, stressed-out driver turns the steering wheel to the left, the brain responds instantaneously by steering back toward the right, he said. This ensures that the driver’s steering is straight, he said.
Read more at Discovery News
May 15, 2016
|A rare, severe form of pulmonary hypertension, which up until now, has only been classified as a human lung disease, has also been discovered in dogs according to a Michigan State University study.|
"Our research is the first to document the existence of pulmonary veno-occlusive disease, or PVOD, in dogs," said Kurt Williams, the lead author of the study and an expert in respiratory pathology in MSU's College of Veterinary Medicine. "PVOD is considered one of the most severe forms of pulmonary hypertension."
The study is published in the journal Veterinary Pathology.
The number of pulmonary hypertension, or PH, cases reported in the United States is low, affecting 15 to 50 people per million each year. PVOD is diagnosed in only about 10 percent of PH cases where no other cause of the disease has been determined. Unfortunately, there are very few effective treatment options for PVOD and a lung transplant often becomes the best choice.
"PVOD might be more common in dogs than in people, but this has yet to be determined and needs to be looked at further," Williams said.
Pulmonary hypertension develops because of abnormal blood vessels in the lungs, which makes it harder for the heart to push blood through and provide oxygen to the rest of the body. In cases of PVOD, the small veins in the lungs become blocked, increasing pressure in these blood vessels, and ultimately causing heart failure.
"The same process happens in canines," Williams said. "These dogs also come in with similar symptoms as humans, yet because subtle changes in health may not be recognized as quickly in dogs, death can occur quickly once the animal is seen by a veterinarian."
Symptoms include cough, increased rate of breathing, respiratory distress, loss of appetite and chronic fatigue. Fatal progression of the disease in humans can last up to two years.
"PVOD is a poorly understood disease not just because it's so rare, but also because there've been no other animals known to have the disease," Williams said. "Our finding changes things."
Read more at Science Daily
A physicist would probably describe what is happening in terms of the particle nature of light. An atom or molecule in the fluorescent tube that is in an excited state spontaneously decays to a lower energy state, releasing a particle called a photon. When the photon enters your eye, something similar happens but in reverse. The photon is absorbed by a molecule in the retina and its energy kicks that molecule into an excited state.
Light is both a particle and a wave, and this duality is fundamental to the physics that rule the Lilliputian world of atoms and molecules. Yet it would seem that in this case the wave nature of light can be safely ignored.
Kater Murch, assistant professor of physics in Arts & Sciences at Washington University in St. Louis, might give you an argument about that. His lab is one of the first in the world to look at spontaneous emission with an instrument sensitive to the wave rather than the particle nature of light, work described in the May 20th issue of Nature Communications.
His experimental instrument consists of an artificial atom (actually a superconducting circuit with two states, or energy levels) and an interferometer, in which the electromagnetic wave of the emitted light interferes with a reference wave of the same frequency.
This manner of detection turns everything upside down, he said. All that a photon detector can tell you about spontaneous emission is whether an atom is in its excited state or its ground state. But the interferometer catches the atom diffusing through a quantum "state space" made up of all the possible combinations, or superpositions, of its two energy states.
This is actually trickier than it sounds because the scientists are tracking a very faint signal (the electromagnetic field associated with one photon), and most of what they see in the interference pattern is quantum noise. But the noise carries complementary information about the state of the artificial atom that allows them to chart its evolution.
When viewed in this way, the artificial atom can move from a lower energy state to a higher energy one even as its follows the inevitable downward trajectory to the ground state. "You'd never see that if you were detecting photons," Murch said.
So different detectors see spontaneous emission very differently. "By looking at the wave nature of light, we are able see this lovely diffusive evolution between the states," Murch said.
But it gets stranger. The fact that an atom's average excitation can increase even when it decays is a sign that how we look at light might give us some control over the atoms that emitted the light, Murch said.
This might sound like a reversal of cause and effect, with the effect pushing on the cause. It is possible only because of one of the weirdest of all the quantum effects: When an atom emits light, quantum physics requires the light and the atom to become connected, or entangled, so that measuring a property of one instantly reveals the value of that property for the other, no matter how far away it is.
Read more at Science Daily
252P was notable for a few reasons. Not only was it a very close call, it is also partnered with another comet, P/2016 BA14, indicating that some time in the pair’s past, they were likely both part of the same object.
After generating world-wide interest, Hubble watched 252P zoom away from Earth and the sun and on April 4 it took a series of images to reveal 252P’s dusty tail was rotating. Immediately, astronomers could conclude that, like a spinning lawn sprinkler, water vapor was blasting from the comet nucleus’ sublimating ices as it rotated, launching dust into space.
These visible light observations were made by Hubble’s Wide Field Camera 3 when the comet was 8.7 million miles away and the time interval between each frame of the animation (top) is between 30 to 50 minutes.
Although the nucleus is far too small for Hubble to resolve (astronomers estimate it to be less than a mile across), the rate of the tail spin gives us an insight to the rate of the nucleus’ spin and could therefore reveal some information about the object’s history as well as the quantity of volatiles it contains.
Comets can be “spin up” through solar radiation heating, a factor that may have led to the original object breaking up in the solar system’s history.
Comet 252P/LINEAR will return to the inner solar system in 2021, but will not come close to our planet for the foreseeable future.
From Discovery News