These beautiful, shimmering tendrils of plasma are all that remain of an ancient massive star that, approximately 8,000 years ago, died and exploded as a supernova. This zoomed-in section of the Veil Nebula has just been released by the Hubble Space Telescope, revealing the intricate beauty that’s left in the wake of one of the most violent events in the universe.
The Veil Nebula is one of the best known supernova remnants in the sky, featuring vast wispy structures of hot plasma some 110 light-years across. The nebula is located around 2,100 light-years away in the constellation Cygnus, the Swan.
Vast as it may be, this new observation features 6 images stitched together as a mosaic, only spanning 2 light-years, providing a very detailed look at the innermost detail of this fascinating object.
The Veil’s brightest components are caused by the ancient supernova’s shock wave that is traveling through interstellar space, blasting into the edge of a cavity, or bubble, etched out into a region of cool interstellar gas. Viewed edge-on, the crumpled structure of the expanding bubble’s leading edge glows in a range of vivid colors, heated by the interaction between the shock waves and cavity gas.
These colors represent the superheated glow of various different gases in the cavity wall — red is the glow of hydrogen; green is sulfur; blue is oxygen. The less defined, more diffuse glow is caused by cooler gases that was heated by the traveling shock wave in the past.
In this extended color image of Pluto taken by NASA’s New Horizons
spacecraft, rounded and bizarrely textured mountains, informally named
the Tartarus Dorsa, rise up along Pluto’s day-night terminator and show
intricate but puzzling patterns of blue-gray ridges and reddish material
in between.
If there’s one thing we’ve learned from NASA’s New Horizons flyby on July 14, it’s that we have a really incomplete understanding of planetary evolution. And now, in a new image release by the Pluto mission, there’s yet another landscape (actually, landscapes) that, for now, defies explanation.
In an eerie observation of Pluto’s terminator (the line that separates Pluto nighttime from sunlight on the dwarf planet’s surface) is a very alien-looking landscape with regular ripples that resemble the scale patterns on a snakeskin. The most exciting thing about this image is that, like most of the high-resolution views being beamed back from the Kuiper belt, planetary scientists only have a vague idea as to what might be going on.
“It’s a unique and perplexing landscape stretching over hundreds of miles,” said William McKinnon, New Horizons Geology, Geophysics and Imaging (GGI) team deputy lead from Washington University in St. Louis, in a Sept. 24 news release. “It looks more like tree bark or dragon scales than geology. This’ll really take time to figure out; maybe it’s some combination of internal tectonic forces and ice sublimation driven by Pluto’s faint sunlight.”
In short, it’s a conundrum, but it sure makes for an intriguing mystery.
While scientists ponder this latest stop on Pluto’s mystery tour, more stunning imagery has been downlinked, including the highest-resolution color view of Pluto yet, with zoomed-in potions of the tiny world’s heart-shaped region, on a plane informally called Sputnik Planum. You can get lost in the full-resolution image here.
Detail of the interface between Sputnik Planum and surrounding mountainous region.
The region, that has already been identified as possessing vast flows of exotic ices, also has what appear to be small rocky islands of material focused around the adjoining “cells” of icy material. Dunes, or features with a dune-like appearance, are also present. Closer analysis of these cells have revealed the icy surface is of a corrugated texture — another feature that is being explained by educated guesswork. Mission scientists think the texture may be down to sublimation processes — where ice is heated and turns into gas, creating Pluto’s thin atmosphere.
Detail of the high-resolution images of Pluto's Sputnik Planum taken by
NASA’s New Horizons spacecraft just before closest approach on July 14,
2015, are the sharpest images to date of Pluto’s varied
terrain—revealing details down to scales of 270 meters.
Additional information about the distribution of methane ices have also been acquired, presenting more questions than answers. One puzzle is that methane ices are abundant across Sputnik Planum’s planes, but mysteriously lacking from another large region informally called Cthulhu Regio. Besides Sputnik, methane ice seems to be abundant in brighter regions of the surface, accumulating in planes and crater rims. Inside craters, however, there’s none.
Viruses have been difficult to classify, with some scientists arguing that they are just nonliving bits of DNA and RNA, yet new research not only finds that they are very much alive, but that they also emerged before the first modern cells.
Viruses have therefore just been placed on the tree of life, occupying the senior-most spot right at the bottom of the tree. They are not "animal, vegetable or mineral," as the saying goes, but exist within their own unique group, according to a new study.
"For now, we call it the 'viral supergroup,' just short of 'superkingdom' or 'domain,' which are words that are quite charged with meanings," Gustavo Caetano-Anoll's of the University of Illinois and the Carl R. Woese Institute for Genomic Biology told Discovery News. He co-authored the study, published this week in the journal Science Advances.
Arshan Nasir, who is Caetano-Anollés' graduate student and also worked on the study, added that "viruses are living. They simply have an atypical mode of living that is slightly different from ours. They are not fully independent. Instead, they move in and out of our bodies, stealing the resources and producing their offspring. In short, we need to broaden how we define life and its associated activities."
Viruses are challenging to study because the sequences that encode their genomes are subject to rapid change. As a result, the scientists elected to study what are known as "folds": the structural building blocks of proteins that give proteins their complex, three-dimensional shapes.
The scientists compared fold structures across different branches on the tree of life, reconstructing the evolutionary history of the folds and of the organisms whose genomes code for them. The researchers did this for 5,080 organisms representing every branch of the tree of life, including 3,460 viruses.
They identified 442 protein folds shared between cells and viruses, and 66 that are unique to viruses.
Nasir said that "a large number of viral genes are nothing like we have seen so far in the cellular world. They are most likely new genes created by viruses."
The researchers theorize that viruses evolved at a time when primordial cells were extruding genetic material, which viruses could then acquire. Most viruses then gained the ability to encapsulate themselves in protective protein coats, called capsids, which became more sophisticated over time. Capsids allowed viruses to become infectious to cells that had previously resisted them.
Viruses, Caetano-Anollés said, "can be visualized as cells that have lost and lost genetic material in exchange for reaping the benefits of their interactions with other cells."
As Nasir said, however, viruses also likely generate their own new genes, with some viruses becoming gigantic. On the tiny end of the spectrum there are viruses like Ebola, which only has seven genes. On the larger end are more recently discovered mimiviruses that have genomes as big, or bigger than, those of parasitic bacteria.
Andrew Camilli, a professor of molecular biology and microbiology at Tufts University, agrees that viruses are "living creatures."
"This belief stems from the fact that viruses have their own complex genome, they replicate to make more of themselves, and they are evolving," he told Discovery News.
Researchers in Portugal have found the first radiological outline of a kidney in an ancient Egyptian mummy and the oldest case of renal tuberculosis.
Kept at the National Museum of Archaeology in Lisbon, Portugal, the mummy, of unknown provenance, dates back to some 2,800 years.
“It’s a male named Irtieru. We do not know exactly what he did in life, but the quality of his cartonnage links him to an elite family,” professor of Egyptology at the American University in Cairo, told Discovery News.
She noted the white cartonnage decorated in polychrome, on which Irtieru's name is painted vertically, is typical of the Twenty-Second Dynasty (about 945–712 BC).
X-Rays (radiography and CT scans) revealed Irtieru rests in his coffin with his arms lying alongside his body and with his hands crossed over his body. He was tall for his time, about 5.61 feet, and died between 35 and 45 years of age.
The researchers’ attention, however, was drawn by a small, bean-shaped structure at the left lumbar region. To their knowledge, this is the first time a kidney has been depicted in X-Rays.
“This kidney display only happened as a consequence of a pathologic preservation, since Irtieru was affected by an end-stage renal tuberculosis,” Carlos Prates, a radiologist at Imagens Médicas Integradas in Lisbon, told Discovery News.
Calcification outlines Irtieru’s putty kidney. The disease is characterized by a slow progression of fibrous lesions and calcifications.
Detailing their findings in The International Journal of Paleopathology, Prates, Ikram and colleagues argue that the diagnosis for kidney turberculosis is supported by the anatomical location, and morphologic and structural analysis of the organ.
Prates added that the only known transformative process that could lead to such condition is renal tuberculosis.
“If this diagnosis is correct this would be the oldest recorded case of this disease,” the researchers wrote.
Irtieru's renal disorder is the reason his kidney was visible in the radiological analysis.
Kidneys did not seem to be well understood in ancient Egypt. The Greek historian Diodorus Siculus reported that these organs were usually not removed, because they were considered unimportant and difficult to extract through the embalming cut.
“It is possible that kidneys exist in more mummies but simply have gone unnoticed,” Ikram said.
She added these organs completely decay or are altered by the embalming process to the point that they become indistinguishable.
Most likely, kidney turbeculosis wasn’t Irtieru's cause of death.
“Earlier on, sometimes several years, Irtieru's must have endured, and resisted, a more threatening event: his initial lung infection,” he said.
Early humans heard sounds differently than we do today, according to new research that provides intriguing clues on the environments our ancestors were living in, and how prehistoric humans communicated with each other.
A key finding of the study, published in the journal Science Advances, is that our ancestors living in South Africa around 2 million years ago were extremely sensitive to close-range sounds, hearing them more keenly than both our species and chimpanzees do now.
"We concluded that Australopithecus africanus and Paranthropus robustus had a heightened sensitivity to sound between 1.0-3.0 kHz compared with both chimpanzees and humans," lead author Rolf Quam, an assistant professor of anthropology at Binghamton University, told Discovery News.
He added that these early humans "were capable of hearing softer sounds" than our species and chimps can.
Quam and colleagues made the determination after reconstructing the internal anatomy of the ears of the two prehistoric humans. To do so, the researchers used CT scans and virtual computer reconstructions based on fossils. The particular human species were selected for the study because their remains include preserved ear bones.
The sensitivity to short-range sounds likely would have facilitated up close communication in an open habitat. Prior research on the tooth enamel of the prehistoric humans found evidence for consumption of foods found in both forests and savannahs, so our South African ancestors must have divided their time between these two environments.
Retreating to the forest might have been necessary, since humans were on the menu at the time for a wide range of large predators, such as leopards, lions and hyenas.
In terms of how the prehistoric humans would have been communicating with each other, there is a general consensus among anthropologists that the small brain size, ape-like cranial anatomy and vocal tract of these individuals would not have given them the capacity for language.
Like other primates, though, they would have been emitting meaningful vowel-based calls. Quam and his team propose also propose that they could have used what are known as "voiceless consonants."
"These are consonants that are produced solely by air flowing through the lips, teeth and tongue, such as the sounds in English associated with the letters "t," "k," "f" and "s," Quam explained. "These are considered 'voiceless consonants' because the vocal chords do not move when they are produced."
It is possible then that human speech evolved through the addition of these articulatory sounds to the vowel-based calls. Quam pointed out that humans are unique among animals in that our communication system relies heavily on the use of consonants, in addition to vowels.
Our ancestors were probably using a lot of visual communication as well, and might even have whispered, given their ability to hear close, quiet sounds so sharply.
Jeffrey Schwartz, a professor in the Departments of Anthropology, History and Philosophy of Science at the University of Pittsburgh, told Discovery News that "this amazingly interesting and intriguing study…clearly adds a new dimension to the study of hominin (early human) sociality and behavior."
Schwartz agrees that early humans in South Africa likely did have a sense of hearing that was "non-sapiens," meaning that it was different than that of our species.
“Don’t tell me what it was designed to do. Tell me what it can do!”
That line was uttered in the movie “Apollo 13,” but could also be applied to the daring eclipse observations that NASA’s Lunar Reconnaissance Orbiter will do of the moon’s surface on Sunday.
Sunday’s eclipse is special as it follows three other total lunar eclipses in the past 18 months (usually you don’t get that many in a row) and the moon will be at its closest point in its orbit to Earth, making it slightly bigger in the sky than usual — an event popularly known as a “Supermoon.”
The LRO has been observing Earth’s satellite since 2009, and wasn’t designed to operate during eclipses. The solar-powered spacecraft would switch off almost everything until sunlight returned again. But as controllers became experienced with the drops in power during LRO’s time in shadow, they got comfortable enough to turn on one instrument: the Diviner.
More formally known as the Diviner Lunar Radiometer Experiment, the instrument looks at day-night changes in temperature on the moon. And it turns out that during an eclipse, the plunge in temperature is sudden — almost like leaving a hot tub for an icy pool, according to NASA. Click here to watch a NASA animation of what it looks like, from the surface of the moon, during a lunar eclipse.
“Ideally we want to measure the full range of temperature variation during the eclipse,” Noah Petro, the deputy project scientist for LRO, told Discovery News. Petro is based at the NASA Goddard Space Flight Center in Maryland.
For most past eclipses, the polar-orbiting spacecraft has been limited to viewing the terminator — the day-night line — where the surface is cool to begin with. This time, the spacecraft will zoom over an area that is more the equivalent of 9 a.m. sunlight on Earth — mid-morning, offering a better sense of how much the temperature changes during an eclipse.
“Most recent (eclipses) have been good, but this will be the sweet spot and the last eclipse for a number of years — not until 2018,” Petro added.
From the past eclipse data, the researchers have seen substantial swings in temperature in a couple of hours — several hundred degrees Fahrenheit — in the soil, particularly in the upper two centimeters. (They can’t see into the soil, but can model it.)
Diviner can sense temperature as deep as 15 centimeters into the lunar soil. Down below that first layer, the soil stays warmer, meaning that top 2 cm must act as a sort of insulator. Models suggest that it’s because the regolith (lunar soil) has space in between the grains.
With each subsequent eclipse, scientists have answered different questions depending on what terrain was underneath, Benjamin Greenhagen, the deputy principal investigator for Diviner, told Discovery News. Previously they were looking at rocky craters (to see the depth of dust over the rocks) and investigated a magnetic anomaly.
Let's start things out in some classy black and white shall we?
If you read this column with even the slightest regularity, you know that the animal kingdom has no shortage of weird sex. Like that of the parasite that devours a fish’s tongue and mates in its mouth. Or the little marsupial that has so much sex it bleeds internally and goes blind and dies. I could go on.
None of it’s particularly elegant. So may I present to you the acrobatic, upside-down sex of the leopard slug, done hanging from a branch on a line of slime. But why, when other slugs do the horizontal tango perfectly fine on the ground? Well, a lot of it has to do with the leopard slug’s gigantic penis, of course.
First things first: Slugs are hermaphrodites, and that’s a neat evolutionary move. Not only does it all but guarantee that any two sexually mature slugs can come together to make babies, it also means that when they do mate, both parties can end up fertilized. In fairness, though, the big disadvantage to hermaphroditism is that it’s more energetically costly to produce both eggs and sperm, as opposed to one or the other.
So, when two leopard slugs find each other, they make their way up a tree and onto a branch. Here they curl around each other and ramp up their release of slime—big time. This appears to be a different formulation than your average leopard slug goo, according to Ben Rowson, a limacologist (that’d be a slug scientist) at the National Museum Wales. The pair will then descend on a slimy rope. “That rope of slime that they hang from can be very strong,” Rowson says. “It’s strong in the moment, but also when it dries out. It’s a fairly tough structure, really.”
Still curled around each other, hanging and gently twirling, the slugs simultaneously unravel their alien-blue penises, which come out of the right side of their head. They do this with hydrostatic pressure, pumping fluids into the penis to enlarge it more and more (the slugs use the same method for controlling their famous eye stalks, by the way).
“These penises, they start off small, but within a few moments you can see just how big they are—they become almost bigger than the slugs themselves,” says Rowson. “The penises are very mobile, it’s almost as if they’ve got a mind of their own. They’re quite complicated structures, and they move continuously and they can change their form quite a lot.”
I’m just going to keep quoting Rowson here, because this stuff is gold. The penises “wrap around each other and they form this kind of chandelier configuration, which is very strange, with these flaps around the edge with a frill on it. And that can pulsate up and down and in and out as the slugs are rotating around. It’s quite the elaborate interaction.”
All the while liquid is pumping into the hugging penises. “They’re pushed out by the fluid inside the body, but these things are so big that I think they take up most of the fluid that’s inside,” Rowson says. “So the rest of the slug looks a bit drained or flattened while all the fluid is in the genitalia.”
What you’re seeing here is illegal in 49 states.
When everything is sufficiently inflated, the transfer of sperm begins. And when everyone is sufficiently fertilized, the slugs will haul themselves back up the rope, though sometimes one partner will simply drop to the ground. Regardless, one of them will consume the slime rope to recoup the resources lost in excreting it. (Interestingly, another slimer, the velvet worm, hunts by spraying its prey with goo. After it has entrapped and eaten the victim, it too devours the spent glue. In nature, you see, there’s no sense in letting resources go to waste.)
The fertilized slugs go off and lay their eggs in soil or a moist log or what have you. Come spring, the eggs will hatch into tiny slugs, thus completing the strange saga that is the leopard slug penis intertwining.
So what gives with such an elaborate method of mating? Well, it seems to be the product of a genital arms race. It may have been that bigger penises in leopard slugs granted their owners better reproductive success and therefore better chances of passing down their genes for larger genitals.
The leopard slug penis got so big, in fact, that its owner has to rely on the laws of physics to unfurl it. “I think that gravity is essential to be able to get the penises out of the body,” says Rowson. “I think it would be impossible for them to mate on a flat surface in the way that they do.” Thus does the slug opt to do its dangle-dance of love.
This strategy, however, would seem to place the leopard slug in dangerous territory, what with predators like birds not exactly being blind and all. But not so, says Rowson. “People tend to overestimate the extent to which slugs are eaten by other animals, because they’re fairly disgusting.” Slime on a non-sexed-up leopard slug is one thing, but a pair dangling from the goo? Forget about it.
Which brings us to another consideration: Slugs are descended from ancient snails, which of course had shells, so why over evolutionary time would slugs ditch that extra protection from predators and desiccation? Why not hold on to the shell just in case?
Well, two reasons. With those big unwieldy shells, snails can’t squeeze into small spaces—say, a crack in a log or some such—where it’s nice and moist. Slugs may not have a shell they can retreat into to avoid drying out, but they have a whole world of crevices to explore.
Decomposing human bodies have a unique smell — one that distinguishes them from other rotting animals, according to new research.
Specifically, human corpses emit a unique five-chemical cocktail — comprised of 3-methylbutyl pentanoate, 3-methylbutyl 3-methylbutyrate, 3-methylbutyl 2-methylbutyrate, butyl pentanoate and propyl hexanoate — that separates them from the rest of the animal kingdom.
These five chemicals are part of a group of molecules called esters, which are also responsible for the strong, sharp smells emitted by fruits like pineapples and raspberries, reports The Guardian.
The human smell of death, in other words, is a little bit fruity.
In collecting gases off of six humans and 26 different animals, researchers identified 452 distinct chemical compounds. Eight of those were specific to humans and pigs, and the five esters were unique to humans.
The esters are produced by degrading muscles, carbohydrates and fat tissues.
Pigs and humans share biological similarities, from growing similar hair to having the same gut flora. For that reason, pigs have been used in most previous decomposition studies. The new research is the first to look at how the two similar animals decompose in the same conditions.
The finding might seem ghoulishly superfluous, but the information has value.
“The mixture of (these) compounds might be used in the future to more specifically train cadaver dogs,” analytical chemist Eva Cuypers told Science.
It may also be useful in assisting party planning for the living: Increasingly elaborate Halloween parties have started to incorporate the smell of death as part of the Halloween experience.
With advancements in the science of the smell of death, then, holiday terror can come in the form of the faint hint of pineapple — as well as a toothless man in an orange jumpsuit accosting you from behind a hay bale.
A tiny bone from underneath a lizard's skin has helped sketched a new picture of life for the first humans living in Australia during the last ice age.
In short, there was a monster in their midst, one that could have grown to almost 20 feet long.
A research team from the University of Queensland (UQ) uncovered a 0.4-inch (1-centimeter) osteoderm -- a bone found under the skin -- just 6.5 feet (2 meters) below ground during a dig in a cave. It's the youngest record of giant lizards in Australia and marks the first evidence that huge apex-predator lizards and the continent's first humans lived at the same time.
UQ paleontologist Gilbert Price and his team date the bone to about 50,000 years ago, which matches up with the arrival on scene of the country's first Aboriginal people.
"Our jaws dropped," Price said in a press release. "The find is pretty significant, especially for the time-frame that it dates."
Australia was home to huge lizards and even 27-foot-long (8.2-meter) crocodiles during the last ice age. But their later disappearance has not been conclusively pinned on humans.
"It's been long-debated whether or not humans or climate change knocked off the giant lizards, alongside the rest of the megafauna," Price explained. "Humans can only now be considered as potential drivers of their extinction."
An osteoderm (skin bone) of a giant monitor lizard was found in the Colosseum Chamber of Australia's Capricorn Caves.
Of course, a key question remains. What creature owned the bone the researchers found?
"We can't tell if the bone is from a Komodo dragon, which once roamed Australia, or an even bigger species like the extinct Megalania monitor lizard, which weighed about 500 kilograms [1,102 pounds] and grew up to six meters [19.7 feet] long," Price said.
Today, the scientists note, the biggest lizard in Australia is the perentie, which maxes out at about 6.5 feet long.
Russian investigators exhumed the remains of the country's last emperor Nicholas II and empress Alexandra as part of a new probe into the notorious 1918 slaying of the Romanov family.
A leading investigator involved in the probe, Vladimir Solovyov, told the Echo of Moscow radio station that they had taken "samples from Nicholas II, from the empress, and from the uniform of emperor Alexander II," the last czar's grandfather, who was himself assassinated in 1881.
"We have decided to start again from the very beginning and carry out renewed examinations," said Solovyov. The remains will be subject to genetic testing, he added.
The powerful Investigative Committee confirmed some of the family's remains were being re-examined, with spokesman Vladimir Markin saying the probe would look into "the circumstances of the death and burial of the imperial family."
The czar, his wife, their five children and their servants were shot by the Bolsheviks and thrown into a mineshaft in 1918 before being burnt and hastily buried.
Russia first looked into the murder of the family after a mass grave was discovered in 1991 near Yekaterinburg in the Urals, where the royal couple and their five children were exiled and shot after the Russian Revolution.
Scientists said that DNA evidence was sufficient to conclude that the grave contained the remains of the czar and czarina, along with three of their daughters, and the government officially identified them in 1998.
The remains were then re-buried in the erstwhile imperial capital Saint Petersburg.
In 2007, a second grave was discovered at a different spot containing two more bodies, believed to be those of the czar's heir Alexei and daughter Maria, who were 13 and 19 years old when they were killed.
But their remains have since been stored at the Russian State Archives, amid doubts over their identity.
While Russian criminal investigators ruled in 2008 that the remains of Alexei and Maria were authentic after DNA testing, their identity has not been accepted neither by the Russian Orthodox Church, which has canonized the last Romanovs, nor by some Romanov descendants.
In July, the resurgent Russian Orthodox Church pressed for the case to reopened.
The question of the authenticity of the remains has taken on fresh urgency ahead of the looming centenary of the murder, as Russia wants to bury all seven family members together.
If you’re a fan of classic acts such as Bob Seger or Mitch Ryder, you know that in Michigan, they love to rock.
Also, they love to collect rocks — in particular, the Petoskey stone, the official state rock. The latter is found on the state’s beaches and sand dunes, where Michigan residents and visitors often collect it as a souvenir, because it has a striking hexagon pattern embedded in its surface that can be brought out with polishing.
The Petoskey has that feature because in addition to being a rock, it’s also a fossil — a remnant of coral that lived in Michigan during the Devonian Period, 350 million years ago. (The hexagon is actually the ancient animal’s mouth.)
Given all that, you can understand how utterly cool it must have been for rock hunter Tim O’Brien of Copenish, Mich., to find a 93-pound Petoskey stone in Lake Michigan, near the town of Northport.
According to the Grand Rapids Press, O’Brien discovered the immense Petoskey a week ago, half-buried in sand several feet out in the lake.
Removing the rock proved to be an arduous affair. It was too big for one person to dig out by hand. O’Brien left and returned another day with his girlfriend, but waves in the lake prevented them from locating it again. Finally, he went back a third time on Sept. 22, equipped with a trowel, and this time was able to dislodge it and carry it to his truck.
O’Brien, who’s been rock-hunting for a few years, told the newspaper that the stone is pretty good quality for its size. Though it might be too big to polish, he plans to put it in his yard for decoration. “It’s just kind of a conversation piece,” he said.
While 93 pounds sounds like a pretty big rock, it’s actually far from the biggest Petoskey ever found. That distinction probably belongs to a specimen found at Sleeping Bear Dunes National Lakeshore in 1999 by a rock hunter named Chuck Schnake. That stone reportedly weighed as much as a ton and measured 40 inches by 20 inches.
The supermassive black hole in the center of our galaxy has started to stir and astronomers are pondering whether the uptick in flare activity has been triggered by the passage of a mysterious dust-enshrouded star.
Until recently, the Milky Way’s supermassive black hole — that resides in a region of our galaxy’s core called Sagittarius A* — has been generating bright flares roughly once every 10 days. Over the past year, however, activity has increased and Sagittarius A* (or Sgr. A* for short) has been flaring roughly once per day.
Using data from 3 space telescopes, astronomers have been able to better understand these powerful flaring events and they may have found a fascinating cosmic connection.
“For several years, we’ve been tracking the X-ray emission from Sgr A*. This includes also the close passage of this dusty object,” said Gabriele Ponti, of the Max Planck Institute for Extraterrestrial Physics in Germany, in a Chandra press release. “A year or so ago, we thought it had absolutely no effect on Sgr A*, but our new data raise the possibility that that might not be the case.”
NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton, with complementary data from NASA’s Swift satellite, were used to piece together Sgr. A*’s activity as a dusty cloud approached the black hole. Discovered in 2011, astronomers were excited by the prospect of an object, called simply “G2″, would encounter Sgr. A*, and possibly be consumed after getting caught in the black hole’s gravitational well. Had this happened, astronomers hoped to see a massive flare, giving humanity a wonderful glimpse into the high-energy processes erupting in a black hole’s accretion disk and event horizon.
Alas, as G2 made close approach in 2014… nothing happened. At least, nothing obvious happened.
Before close approach, it was thought that G2 was most likely a cloud of dust and gas; possible stellar remnants idly orbiting through the galaxy’s core. But after its supermassive encounter, G2 continued on its merry way, zooming around the black hole and orbiting back out into interstellar space. That’s when G2′s nature became clear — it was probably a star, cocooned in a dusty envelope, whose gravity maintained its form and little of the cloud’s material was allowed to be ripped away and fall into the black hole.
Although our supermassive black hole had the munchies, its G2 snack was ripped from its clutches.
No doubt extreme gravitational perturbations disrupted the star and associated cloud, but there was no evidence of any flaring activity, meaning G2 had escaped pretty much intact.
In new research accepted for publication in the journal Monthly Notices of the Royal Astronomical Society, however, it seems that Sgr. A* has been the site of an uptick in flaring activity, a possible sign that some of the dust from G2 did indeed get pulled into the black hole, generating near-daily blasts of X-ray radiation.
“There isn’t universal agreement on what G2 is,” said Mark Morris of the University of California at Los Angeles. “However, the fact that Sgr A* became more active not long after G2 passed by suggests that the matter coming off of G2 might have caused an increase in the black hole’s feeding rate.”
A Stone Age site where cave rituals may have been performed some 9,000 years ago has been discovered on Blå Jungfrun, an island off the east coast of Sweden. The island has long been associated with tales of witchcraft, curses and supernatural powers.
Blå Jungfrun’s “huge boulders and steep cliffs provide a dramatic landscape, and for centuries the uninhabited island has been associated with supernatural powers,” wrote a team of archaeologists in the summary of a presentation given recently at the European Association of Archaeologists annual meeting in Glasgow, Scotland.
According to a centuries-old legend, witches gather every Easter on the island to worship the devil himself. Curses have also been associated with the island. For instance, those who remove a rock from the site are said to endure a lifetime of bad luck.
How far back these beliefs and stories go is unknown. “The time depth of these stories is shrouded in mist but could be considerable,” the archaeologists say.
The team began archaeological fieldwork on the island in the spring of 2014. “The results are astonishing and reveal extensive human activities on the island in the Mesolithic Stone Age,” the archaeologists wrote.
People who travelled to the island may have practiced various rituals inside the two caves, archaeologists say. One cave contains what may be an altar where offerings could have been made to deities. Meanwhile another cave has an area that could have been used like a “theater” or “stage.”
“In two caves, distinct ritual features were identified,” wrote the team members, who hail from Kalmar County Museum and Linnaeus University, both in Sweden. Stone Age rituals?
One cave has a massive hollow, about 2.3 feet (0.7 meters) in diameter, which was hammered into a vertical wall. A fireplace lies underneath the hollow. “We believe the hollow is man-made and that the fireplace has been used in connection to hammering out the hollow, probably several occasions,” said Ludvig Papmehl-Dufay, an archaeologist with Kalmar County Museum.
Archaeologists said they are not certain what took place here; however, one clue comes from the cave’s layout.
“The entrance to the cave is very narrow, and you have to squeeze your way in. [However,] once you’re inside, only half of the cave is covered and you can actually stand above the cave and look down into it, almost like a theater or a stage below,” said Papmehl-Dufay.
The “act of producing the hollow could have been the important part [of the ritual], perhaps even the sound created while doing so,” he said. The noise from the hammering and the sight of the fire burning, as viewed from above, may have created an interesting effect for Stone Age audiences, the researchers said.
The second cave yielded yet more strange clues. Archaeologists found a hammerstone and an area that was used for grinding up material. This area “could have been used to place something in, perhaps as part of some form of offering, like an altar,” Papmehl-Dufay said.
In between the two caves, the archaeologists discovered a small rock shelter, just 20 by 26 feet (6 by 8 meters), that contained stone tools and seal remains. Radiocarbon dating indicates people consumed the seals around 9,000 years ago.
“A few people could have been sitting or standing, perhaps just resting or spending the night during sporadic stays on the island,” Papmehl-Dufay said. “However, more-specific activities with ritual elements to cannot be ruled out, such as feasting in connection to the rituals performed in the nearby caves.” More to discover
Work on the island is continuing as archaeologists try to unravel the secrets of the site’s past. The scientists are currently investigating a layer of material, below one of the caves, that contains quartz that may have been used to help make tools.
More than two-dozen complete fossils of Africa's earliest known coelacanth, a new species named Serenichthys kowiensis, have been found.
The specimens, 30 in total, were discovered near Grahamstown, in the Eastern Cape province of South Africa, in what was once an estuary 360 million years ago.
Paleontologist Robert Gess, of the University of the Witwatersrand, and Michael Coates, from the University of Chicago, worked together to describe the new species from the fossils, which were found by Gess.
"Remarkably," said Gess, in a press release, "all of the delicate whole fish impressions represent juveniles. This suggests that Serenichthys was using a shallow, waterweed-filled embayment of the estuary as a nursery, as many fish do today."
"This glimpse into the early life history of ancient coelacanths raises further questions about the life history of the modern coelacanth, Latimeria, which is known to bear live young, but whether they, too, are clustered in nurseries remains unknown," added Coates.
The coelacanth is believed to date to the Devonian Period, more than 400 million years ago. But only five species from that far back have ever been described, and none from Africa.
Analysis of the new species, however, has helped fill in a bit more of the murky picture of the creature's evolution, the scientists say.
"According to our evolutionary analysis, it is the Devonian species that most closely resembles the line leading to modern coelacanths," said Gess.
Fittingly enough, the new species remains were found only about 100 kilometers (62 miles) from the mouth of the Chalumna River, where the first modern, but still quite mysterious, coelacanth (a fish long thought extinct) was caught in 1938.
Gess and Coates's work is published in Zoological Journal of the Linnean Society of London.
An international team of researchers has unearthed the oldest case of decapitation in the New World — a 9,000-year-old skull buried in Brazil with two severed hands covering the face.
The grave was excavated in 2007 in the rock shelter of Lapa do Santo, an archaeological site which has yielded 26 human burials dating to the early Holocene period. It consisted of a circular pit covered with five limestone cobbles.
There, the archaeologists found a skull with the palms of severed hands arranged over the face in opposite direction.
The right hand was laid over the left side of the face with the fingers pointing to the chin, while the left hand covered the right side of the face, the fingers pointing to the forehead.
A jaw and the first six cervical vertebrae, all bearing v-shaped cut marks, completed the assemblage.
“Using cranial morphology and tooth wear, this individual was estimated to be a young adult male,” André Strauss from the Max Planck Institute for Evolutionary Anthropology, Germany and colleagues wrote in the open-access journal PLOS ONE.
Called Burial 26, the remains date back 9,000 years according to accelerator mass spectrometry. Strontium analysis, comparing the isotopic signature of the bones to other specimens from Lapa do Santo, suggest Burial 26 likely belonged to a local member of the group.
The researchers ruled out the skull was the result of trophy taking, which was common in ancient South America.
“Trophy-heads are usually curated for long periods after being obtained, while Burial 26 was interred not long after death,” Strauss told Discovery News.
He added that trophy heads usually have drill holes in the skull for carrying. Neither drill holes nor an enlargement of the foramen magnum, which is the opening on the bottom of the skull, were observed in Burial 26.
“Moreover, strontium signature does not point to the individual being an outsider, thus representing an enemy,” Strauss said.
The researchers concluded the finding from Lapa do Santo is the oldest case of decapitation in the New World.
Older than other reported cases in North America, Burial 26 almost doubles the chronological depth of the practice of decapitation in South America, where the oldest case, reported from the Andean region, dates back some 5,000 years.
“Geographically, it expands the known range of decapitation by more than 2,000 kilometers, showing that during the early Holocene this was not a phenomenon restricted to the western part of the continent as previously assumed,” Strauss said.
He noted that decapitation in the New World does not necessary mean inter-group violence, but represents a more complex scenario.
According to the researchers, it is very likely that decapitation occurred after death for Burial 26, as part of a procedure which attests to the early sophistication of mortuary rituals among hunter-gatherers in the Americas.
Scientists have long pondered how extremely bright, ancient galaxies known as submillimeter galaxies (SMGs) managed to pump out stars 1,000 times faster than the Milky Way does today.
Two theories have dominated the debate. The first is that galaxy collisions drove short-lived, but spectacular bursts of star formation. The other idea is that SMGs are long-lived structures that accumulated mass over time.
“Neither scenario has been successful in fully replicating the observed properties of SMGs,” astronomer Romeel Dave, with the University of the Western Cape, Cape Town, South Africa, wrote in an essay in this week’s Nature.
A new study, also published Nature, details a computer simulation that, for the first time, matches observed properties of SMGs. The model shows that the galaxies aren’t transient and that they can generate stars at the incredible rate of 500- to 1,000 solar-mass stars PER YEAR for a billion years.
What makes them so productive? The simulation suggests the galaxies, which date back to about 3 billion years after the Big Bang, tapped reservoirs of gas to form new stars, rather than rely on mergers with other galaxies.
“In a nutshell, the authors find that SMGs plausibly arise from a ‘perfect storm’ of high rates of gravitationally driven gas accretion, the recycling of previously ejected material and contributions to the systems’ submillimetre luminosity from nearby galaxies,” Dave wrote.
Scientists have discovered an unexpectedly regular cycle of ice formation and depletion on the surface of a comet, a pattern tied to an orbital dance of shadow and sunlight.
Measurements taken by the European Space Agency’s Rosetta spacecraft, currently orbiting comet 67P/Churyumov-Gerasimenko, show that ice builds up when a particular region of the comet is in shadow. The ice then transitions, or sublimates, to gaseous water vapor when that region shifts into sunlight.
“We observed this cycle for several comet rotations … We were surprised to see so clearly the appearance and disappearance of the ice due to temperature and illumination conditions,” planetary scientist Maria Cristina De Sanctis, with the Institute for Space Astrophysics and Planetology in Rome, wrote in an email to Discovery News.
The finding helps resolve a puzzle about why a comet’s surface can be relatively free of ice, such as what has been observed on 67P and other comets, even though the bodies are outgassing water. The cycle of condensation and sublimation shows how water ice can be transported from the interior of the comet to the surface.
“This water cycle appears to be an important process in the evolution of the comet,” researchers wrote in an article published in this week’s Nature.
The cycle also helps explain why comets stay active. “In some way, it can prolong the comet’s life,” De Sanctis added.
Scientists are not yet sure if the water cycle accounts for 67Ps’ odd twin-lobed, duck shape. One theory is that 67P originally was two comets that melded together over time. The other idea is that the region between the comet’s lobes, informally referred to as “the neck”, has been especially active over time, causing a gradual reshaping of what was once a rounder (and single) body.
“There is a strong debate about this issue,” De Sanctis said. “Personally, I think that the neck region can be the result of an evolution of the comet that experienced different thermal regimes at different distance from the sun."
"Rosetta sees that at relatively large distances from the sun, the neck region is the most active and thus it is also the one that is most largely affected by the condensation and sublimation phenomena," she said.
Can’t see the wood for the trees? Well, the same is often true for our galaxy’s center, where the stars and clouds of dust can be so dense we have great difficulty seeing objects in the Milky Way’s core.
Fortunately, astronomers have many different wavelengths to study and it turns out that a specific type of star can highlight its presence like a flare in the night through its interaction with the interstellar medium.
“There’s a lot we don’t know about the galactic center, and a lot we want to learn,” said Idan Ginsburg, of the Harvard-Smithsonian Center for Astrophysics (CfA) and lead author of a study accepted for publication in the Monthly Notices of the Royal Astronomical Society. “Using this technique, we think we can find stars that no one has seen before.”
Although most stars in the galactic core will forever remain hidden, stars traveling faster than the speed of sound in that medium generate powerful shock waves through the gas and dust. This interaction can accelerate electrons that, in turn, generate a specific type of emission — called synchrotron radiation — which could possibly be detected by sensitive radio observatories on Earth.
“In a sense, we’re looking for the cosmic equivalent of a sonic boom from an airplane,” said Ginsburg.
Indeed, a supersonic airplane travels faster than the speed of sound in atmospheric gases. The sonic “boom” is the sound of the atmospheric shock wave racing past your location. In the case of supersonic stars, the shock wave generated is a dense region generating radio emissions, highlighting the star’s location, but the star is moving at a much higher speed than a supersonic aircraft.
To produce a stellar shock wave, a star needs to move at a speed of thousands of miles per second (as a comparison, a supersonic aircraft breaks the speed of sound at 768 miles per hour). Usually, for the majority of our galaxy, acquiring this speed is rare, but in the galactic core, where the supermassive black hole (called Sagittarius A*, or Sgr A*) resides, stars are accelerated to these mind-boggling speeds.
Like a swarm of bees flying around an invisible point, when stars orbiting Sgr A* make close approach, the black hole’s powerful gravity will accelerate these stars to thousands of miles per second, likely generating powerful “sonic booms” that could be detected. And Ginsburg’s team already have a known candidate star to test their detection method out on.
A new 30-foot-long dinosaur has just been discovered in Alaska, according to a team of researchers who believe the dino once stomped through snow and endured months of winter darkness.
The duck-billed plant eater, named Ugrunaaluk kuukpikensis meaning “ancient grazer of the Colville River,” is the northernmost dinosaur known to have ever lived, Florida State University professor of biological science Greg Erickson and his colleagues say.
Colville River refers to the place where the dino remains, dated to 69 million years ago, were found. The site, the Prince Creek Formation, is in northern Alaska.
“The finding of dinosaurs this far north challenges everything we thought about a dinosaur’s physiology,” Erickson said in a press release. “It creates this natural question. How did they survive up here?”
Not very well, at least for a herd of U. kukkpikensis juveniles whose remains — along with those of older individuals — were found by the paleontologists. Measuring about 9 feet tall, the young dinosaurs in the herd suddenly died at once, the researchers believe, although the cause of death remains a mystery for now.
Despite this tragedy, it appears that multiple animals lived in the region at the time. They included this new species of dinosaur, plus at least 12 other dino species, based on teeth and other remains. Birds, small mammals and some fish rounded out the diverse ecosystem.
Earth’s climate was much warmer then, on average, and what is now Arctic Alaska was covered in trees. Still, because the area was so far north, the scientists believe that the dinosaurs likely contended with months of winter darkness. Temperatures averaged about 43 degrees Fahrenheit, and the dinosaurs probably experienced snow.
“What we’re finding is basically this lost world of dinosaurs with many new forms completely new to science,” Erickson, who is originally from Alaska, said.
He added, “It’s virtually unexplored in terms of vertebrate paleontology. So, we think we’re going to find a lot of new species.”
An “unusual” new archaeological find could be the long-lost Tomb of the Maccabees, a burial site of leaders of a band of Jewish rebels from the second century B.C.
Israeli archeologists discovered the strange, pillared structure at the Horbat Ha-Gardi site near the ancient city of Modi’in. First excavated 150 years ago, this site was thought to be the mausoleum of a priest named Mattathias the Hasmonean and his five sons, who led a rebellion against Greek rule of Judea. Later study suggested it was instead an early Christian site, from several hundred years later.
The new excavations haven’t fully solved the mystery, but archaeologists say they can’t rule out that the Maccabees were buried there.
“If what we uncovered is not the Tomb of the Maccabees itself, then there is a high probability that this is the site that early Christianity identified as the royal funerary enclosure [for the Maccabees], and therefore, perhaps, erected the structure,” Dan Shachar and Amit Re’em, the directors of the excavation for the Israel Antiquities Authority, said in a statement.
The story of the Maccabees
Alexander the Great conquered Judea, in what is now southern Israel, from the Persians in 332 B.C. After Alexander’s death, his empire fractured. Judea came under the rule of the Seleucid Empire, which stretched from modern-day Turkey through the Middle East all the way into northwest India.
The Seleucids were a Hellenistic dynasty, and they aggressively moved to bring a Greek influence to Judea. According to the historical Hebrew text 1 Maccabees, the ruler Antiochus IV Epiphanes suppressed Jewish law and outlawed rites such as circumcision. He also instituted pagan rituals at the holy Second Temple in Jerusalem, desecrating it in the eyes of the Jewish residents.
Then, the story goes, a Jewish priest named Mattathias (or Matityahu) rebelled. He and his five sons launched a campaign against the Hellenistic rulers. Mattathias died in 166 B.C. or so, and his son Judah took over as leader of the rebel army. In 165 B.C., the rebels successfully wrested control of Judea from the Seleucid dynasty, liberating the temple.
It was during the liberation and re-dedication of the temple that the festival of Hanukkah was born. According to the Talmud (the central Hebrew text of Judaism), the victorious Jews could find only one flask of holy, sealed olive oil, which was needed to burn constantly to cleanse the temple. Miraculously, the single flask burned for eight days, keeping the flame alive until more holy oil was found.
Lost mausoleum
The victory of the Maccabees made Judea a semi-autonomous region within the Seleucid Empire and launched the Hasmonean dynasty. Judah, the first ruler of the dynasty, continued the battle to conquer back more territory after reclaiming the Temple, but died on the battlefield in 160 B.C. His brother Jonathan took the throne until he was assassinated in 142 B.C., and was then succeeded by his younger brother Simon. Simon’s son-in-law murdered him in 134 B.C. and took the throne. The royal burial places have never been found.
When Antiochus died in 129 B.C., Judea became independent. The Hasmoneans ruled until becoming a client kingdom of Rome in 63 B.C. Their dynasty held on until the Roman Senate appointed Herod king in 37 B.C.
About 150 years ago, archaeologists first excavated at the Horbat Ha-Gardi site, suspecting that it might hold the remains of the ancient city of Modi’in. They found a mausoleum built upon huge pillars, supporting slabs that might once have been the floor of a second story. The discoverers declared that the ruins matched the historical descriptions of the tomb of the Maccabee rulers, according to the Israel Antiquities Authority. That tomb was said to overlook the sea and to bear pyramid-shaped roofs.
Soon, though, the French archaeologist Charles Simon Clermont-Ganneau threw a wrench into the narrative. Clermont-Ganneau, who conducted excavations in the Middle East through the 1870s and 1880s, discovered mosaics with crosses on them in the burial vault floors. He suspected that the structure dated to the early days of Christianity, though it might have been built over the original tomb of the Maccabees to celebrate them, he wrote.
The world’s oldest flour was made from oat some 32,000 years ago, according to a new analysis of a Paleolithic stone tool.
Recovered in 1989 from a cave in southeastern Italy called Grotta Paglicci, in a layer dating to the Gravettian period about 32,000 years ago, the pestle-type stone was used by hunter-gatherers who made intensive use of the cave.
They left behind wall paintings of horses and hands, human burials and distinctive artifacts, as shown by previous research carried out by Arturo Palma di Cesnola and Annamaria Ronchitelli of the University of Siena, in collaboration with the Archaeological Superintendency of Puglia.
The elongated cobble of sandstone measures about 5 inches long, it’s broken at one end and rounded at the other and features longitudinal fissures on its surface.
“On the basis of the functional analysis, this item has been interpreted as a peste-grinder,” Marta Mariotti Lippi, a botany professor at the University of Florence, Anna Revedin, of the Italian Institute of Prehistory and Protohistory in Florence, Biancamaria Aranguren of the Archaeology Superintendency of Tuscany and colleagues wrote in in the Proceedings of the National Academy of Sciences.
They noted the rounded end was used to crush seeds, while the stone’s flat surface allowed to grind the broken seeds into flour.
Although it was carefully investigated at the time it came to light, the stone tool was recently subjected to new analysis in order to recover possible bits of starch grain still intact.
The sampling method, adopted for the first time in this research, involved wrapping the stone in a plastic film, to preserve it for further analysis. The researchers exposed only three tiny patches and washed them to recovery loosen debris.
“Overall, about 1,000 starch grains were observed,” the researchers wrote.
They included acorns and relatives of millet, but the most plentiful starch grains were those from wild Avena (oat) species.
Previous starch analysis on grinding stones from Bilancino in the Tuscan Mugello Valley, Kostenki 16 at Pokrovsky Valley, Russia and Pavlov VI in the Czech Republic showed plant exploitation was already spread across Europe during the Mid-Upper Paleolithic.
But the finding at the Grotta Paglicci represents the most ancient evidence of the processing of oat.
The biologists at the University of Florence recorded a great number of swollen and partly gelatinized grains, featuring the physico-chemical changes that occurs after thermal treatments.
“Grinding oat requires a previous drying of the grains to be processed,” Anna Revedin told Discovery News.
“Given a climate colder than the current one, the inhabitants of Grotta Paglicci likely used heating to accelerate drying,” Revedin said.
She added that heat treatment of oat helps its preservation while improving the flavor and nutritional properties.
“The early modern humans of Grotta Paglicci already had a knowledge that included a multi-step technology and surprising skills in processing food plants,” Revedin said.
The early Gravettian inhabitants of the cave are the most ancient population to use a method that involves at least four steps in preparing plants for consumption.
While the stone tool showed the grains were heated and ground, there is no direct evidence for the following steps, which are the mixing of the flour with water and the cooking.
However, the processes can be plausibly hypothesized, the researchers said.
“Rehydration is necessary for cooking and cooking is necessary to make the starch digestible,” they said.
Like the Peanuts character, Pigpen, each of us emits a cloud of bacteria that is uniquely our own, according to a new study.
This "personal microbial cloud" is so distinctive that researchers can even identify someone just by studying the air in that individual’s room.
"We expected that we would be able to detect the human microbiome in the air around a person, but we were surprised to find that we could identify most of the occupants just by sampling their microbial cloud," lead author James F. Meadow, a postdoctoral researcher formerly from the Biology and the Built Environment Center at the University of Oregon, said in a press release.
Meadow and his team asked 11 volunteers to sit, one by one, in a sanitized experimental chamber. The scientists next sequenced the microbes in the air of the chamber after each person left.
This work in itself was a monumental task, as the researchers looked at more than 14 million sequences representing thousands of different types of bacteria found in the 312 samples from air and dust obtained in the experimental chamber.
The scientists found that most of the occupants, after sitting alone in the chamber for about 4 hours, could be identified just by the unique combinations of bacteria that they left behind in the surrounding air.
The study focused on categorizing whole microbial communities rather than identifying pathogens. Meadow and his colleagues did, however, find a lot of Streptococcus, which is commonly found in the mouth.
They also identified Propionibacterium and Corynebacterium, which are both common skin residents. In fact, all of the test subjects emitted these three widespread types of microbes.
Different combinations of bacteria, however, were identified for nearly all of the study participants.
"Our results confirm that an occupied space is microbially distinct from an unoccupied one, and demonstrate for the first time that individuals release their own personalized microbial cloud," the authors concluded.
With the huge supermoon lunar eclipse just one week away, it's time to dust off your small telescopes and binoculars, track down an observatory event or webcast, or draft your invitations for a moon-cake party. Don't wait too long — if you miss it, the next one isn't until 2033.
The supermoon lunar eclipse of 2015 will occur Sunday, Sept. 27, and is a confluence of three events: a full moon; a lunar eclipse, in which the Earth blocks the sun's light from hitting the moon; and lunar perigee, when the moon is in the closest part of its orbit to Earth. The last time such a confluence happened was in 1982; there were just five instances of it in the 20th century. This time around, viewers looking from the Americas, Europe, Africa, western Asia and the eastern Pacific Ocean will have a chance to see the show.
During lunar perigee, the moon appears larger and brighter in the sky, which is why a full moon coinciding with perigee is known as a "supermoon." (A "minimoon" is when the full moon is at its farthest point from the Earth.) This large moon will present the perfect canvas to watch the Earth's shadow slide over and block the moon's light.
As if that weren't spectacular enough, there's the origin of the eclipse's other name, "blood moon." The moon doesn't simply disappear into Earth's shadow during a lunar eclipse; instead, it's illuminated by an eerie, reddish glow of the light refracting through the edges of Earth's atmosphere.
The moon will be shrouded in shadow Sunday night or early Monday morning (depending on the time zone). It will enter the dark part of the Earth's shadow at 9:07 EDT Sunday (0107 GMT), and it will enter a total eclipse by 10:11 p.m. EDT (0211 GMT Monday) beforebegin to emerge from shadow 12 minutes later. Areas that cannot see the full eclipse, because sunset comes too late or sunrise too early, may still be able to see part of the moon obscured.
Several webcasts are planned to stream live views of the eclipse online. The Slooh Community Observatory, a skywatching website that provides users access to remotely operated telescopes, will offer a flagship webcast of the lunar eclipse that can be accessed at the Slooh website, where visitors can also find Slooh's archive of past webcasts.
After going nearly a decade without any male contact, a female yellow-bellied water snake in Missouri has given birth to offspring two summers in a row, officials say.
While none of this year's offspring survived, two of the snakes born last summer are healthy and now serving as educational reptiles.
"There is always a high proportion of infertile eggs due to chromosome combination, but a few can be successful and hatch if the mother has a dissimilar sex chromosome," herpetologist Jeff Briggler explains in a news release.
Scientifically known as "parthenogenesis," the so-called 'virgin births' were originally thought to be the product of sperm stored within the female's body for long periods of time. Experts say, however, that this female snake's eight-year dry spell is likely too long for viable sperm to have survived.
While this is the first instance of a yellow-bellied water snake reproducing asexually, parthenogenesis has previously been observed in other species both in the wild and in captivity. The practice is relatively common in lizards and insects, and has also been noted in some species of sharks and snakes.
Mammals are not known to reproduce via parthenogenesis.
The largest meat-eating dinosaur ever discovered in Australia had sickle-shaped claws the size of chef’s knives, a daunting feature that likely made up for its fairly delicate jaws and small teeth, a new study finds.
The dinosaur’s 10-inch-long (25 centimeters) claws likely helped it hunt, said study lead researcher Phil Bell, a lecturer of paleontology at the University of New England in Australia.
“They didn’t have skulls like T. rex, which could crush bones with their incredible bite,” Bell told Live Science. “Instead, they probably used their hands and massive claws — a bit like a raptor — to bring down their prey.”
The newfound claw-wielding dinosaur lived about 110 million years ago, during the mid-Cretaceous, and likely measured about 20 feet (6 meters) long. Miners discovered and excavated the partial skeleton in the 1990s in the opal fields near the town of Lightning Ridge, located in New South Wales in eastern Australia. The fossils, most of them a bluish hue, thanks to the opals, were donated to the Australian Opal Centre in 2005, and remained on display until Bell and his colleagues decided to study them.
Unfortunately, the miners may have missed or destroyed some of the fossils, and fresh breaks on the bones suggest they were damaged during excavation, the researchers said. Still, the finding is the second most-complete skeleton of a theropod (a group of bipedal, mostly meat-eating dinosaurs) from Australia, Bell said.
The researchers chose not to name the new species just yet — primarily because the skeleton is incomplete — but are calling it “lightning claw” for now in honor of its location and impressively sized claws.
Origin dilemma
Scientists are sure of one thing: Lightning claw is a megaraptorid, an enigmatic group of theropod dinosaurs that sported long claws and lived on the southern supercontinent Gondwana. Researchers have found other remains of megaraptorids in South America and Australia.
However, they are unsure where megaraptorids sit in the theropod family tree. Some researchers suspect the group belongs to the tyrannosaur branch (the dinosaurs that evolved into birds), and others say it’s more closely related to primitive theropods, such as Allosaurus and Carcharodontosaurus, the researchers said.
The authors didn’t use lightning claw to help solve the mystery because “there’s only so much you can answer at one time,” Bell said. “The issue of where megaraptorids sit in the great family tree of theropoda is a much bigger problem than trying to identify a single species, for example.”
But the finding does provide clues about the origin of megaraptorids. Lightning claw predates the oldest known megaraptorid found in Australia (Australovenator) by 10 million years. Moreover, Australia is largely known as a fossil “dark continent” because it has divulged few dinosaur fossils compared to the other continents (with the exception of Antarctica).
Despite Australia’s dearth of uncovered dinosaur fossils, the bluish specimen suggests that some megaraptorids may have originated Down Under.
Scientists from 11 institutions have released the first draft of the Open Tree of Life, an exhaustive project that traces the evolutionary relationships between all of the 2.3 million identified species of plants, animals, microbes and fungi on Earth.
An amalgamation and expansion of hundreds of smaller evolutionary trees, the open-source initiative is available for public viewing at http://tree.opentreeoflife.org.
“Understanding how the millions of species on Earth are related to one another helps scientists discover new drugs, increase crop and livestock yields, and trace the origins and spread of infectious diseases such as HIV, Ebola and influenza,” the research team explains in a news release.
The tree is far from complete; much of the evolutionary information required to finish the project is not yet available digitally. Researchers estimate that current digital evolutionary databases contain DNA for less than 5 percent of Earth’s species.
Nonetheless, the completion of the project’s first draft is a major milestone in the democratization of scientific data.
“Twenty five years ago people said this goal of huge trees was impossible,” co-author Douglas Soltis, of the University of Florida, remarked. “The Open Tree of Life is an important starting point that other investigators can now refine and improve for decades to come.”
The remnants of ancient water wells, pearls and hairpins are proof that a group of villagers set up a settlement on top of a military fort in ancient Roman times.
About 1,900 years ago, a group of Roman soldiers lived in a fort in what is now Gernsheim, a German town located on the Rhine River about 31 miles (50 kilometers) south of Frankfurt. Shortly after the soldiers left the fort in about A.D. 120, another group of people moved in and built a village literally on top of the settlement, researchers found.
Archaeologists have known about the site itself since the 1800s, but the new finding sheds light on its inhabitants and what they did for fun. (An ancient die and game piece were among the discoveries.)
“We now know that from the first to the third century, an important villagelike settlement, or ‘vicus,’ must have existed here,” dig leader Thomas Maurer, an archaeologist at the University of Frankfurt, said in a statement.
After excavating the fort last year, the researchers returned this summer to look for evidence of the Roman settlement. Their efforts paid off: They found relics of the village, part of it built on the foundations of the fort.
Excavation efforts, which began Aug. 3 and will last until early October, have already uncovered handfuls of artifacts. Researchers have found the well-preserved foundation of a stone building, fire pits, at least two wells and some cellar pits. They’ve also found ceramic shards, which they plan to date to get a better grasp of the village’s active periods.
“We’ve also found real treasures, such as rare garment clasps, several pearls, parts of a board game (dice, playing pieces) and a hairpin made from bone and crowned with a female bust,” Maurer said in the statement.
Who lived there?
Though they built their settlement over part of the fort, the villagers likely knew the soldiers, the researchers said. In fact, the villagers were likely the soldiers’ family members and tradespeople who made a business trading with the military.
“A temporary downturn probably resulted when the troops left — this is something we know from sites which have been studied more thoroughly,” Maurer said. But the little village managed to prosper after the soldiers left, as stone buildings were built in the second century A.D., during the Pax Romana, a 206-year period with relatively few conflicts in the Roman Empire.
The inhabitants likely had Gallic-Germanic origins, but a few “true” Romans — people with Roman citizenship who had moved from distant provinces — lived there as well, the researchers said. They based this idea on several tidbits of evidence, including pieces of traditional dress and coins found there. One coin is from Bithynia, in northwest Anatolia (modern-day Turkey), which may have been a souvenir from someone’s travels, they said. The fort next door
The Roman fort once housed about 500 soldiers, who lived there between about A.D. 70 and 120, the researchers said. When the soldiers left, they dismantled the fort and filled in the ditches with dirt and everyday bric-a-brac, much to the delight of the archaeologists excavating the site.
It was “a stroke of luck,” said Hans-Markus von Kaenel, a retired professor of archaeology at the Institute for Archaeological Sciences at Goethe University in Frankfurt. More than 50 papers have been published on the findings, which Von Kaenel, his colleagues and students have worked on for almost 20 years.
Despite initial speculation that Pluto could be similar to Neptune’s moon Triton, early data from NASA’s New Horizons spacecraft shows Pluto is a different beast indeed.
Last year, a map was released of Triton showing the moon in its clearest detail yet. The map was based on Voyager 2 data when the spacecraft flew past the moon in 1989, as part of a larger solar system tour.
Produced by Paul Schenk at the Lunar and Planetary Institute in Houston, the map was made in part to compare Triton to Pluto. Both are bodies originating in the outer solar system, and it was thought there could be at least some similar features on them.
But as high-resolution data comes in slowly from New Horizons, winging its way out of the solar system, the surprise is just how little similarity there is, Schenk told Discovery News. Even the youngest features are very different between the two bodies.
“The central lesson here is that no two bodies in this part of the solar system are going to look alike or have the same geologic history,” Schenk said.
Scientists knew upfront there would be differences, to be sure. Triton is a fugitive of the outer solar system captured by Neptune long ago. The force of that gravitational capture melted vast plains on Triton’s surface, wiping away older craters and terrain.
Pluto, meanwhile, has been quietly orbiting in the outer solar system for billions of years and didn’t go through that kind of perturbation. So its terrain was already expected to be somewhat older, craggier and more cratered.
But there are mysteries that go beyond their different geologic histories, Schenk said. The youngest terrain on Pluto (Sputnik Planum) appears vastly different than young terrain on Triton. And there are mountains on Pluto that are hard to explain on a cold dwarf planet.
Beyond that, there’s a vast nitrogen ice sheet on its surface; how it got there and whether Triton (placed in the same spot as Pluto) could host such a phenomenon are open questions, Schenk explained.
A cell's life is a noisy affair. These building blocks of life are constantly changing. They can spontaneously express different proteins and genes, change shape and size, die or resist dying, or become damaged and cancerous. Even within a population of the same type of cell, there is immense random variability between cells' structures, levels of protein expression, and sizes.
"High dimensionality and noise are inherent properties of large intracellular networks," said Adilson E. Motter, the Charles E. and Emma H. Morrison Professor of Physics and Astronomy in Northwestern University's Weinberg College of Arts and Sciences. "Both have long been regarded as obstacles to the rational control of cellular behavior."
Motter and his collaborators at Northwestern have challenged and redefined this long-held belief. Using a newly-developed computational algorithm, they showed that this randomness within and among cells, called "noise," can be manipulated to control the networks that govern the workings of living cells -- promoting cellular health and potentially alleviating diseases such as cancer.
Supported by the National Cancer Institute Physical Science-Oncology Center at Northwestern and the National Science Foundation, the research is described in the September 16 issue of the journal Physical Review X. Motter and William L. Kath, professor of Engineering Sciences and Applied Mathematics, are coauthors of the paper. Daniel K.Wells, a graduate student in applied math, is the paper's first author.
"Noise refers to the random aspects of cell behavior, especially gene regulation," Wells said. "Gene regulation is not like a train station, where gene expression-regulating proteins are shipped in at regular intervals, turn a gene on or off, and then are shipped out. Instead, gene expression is constantly, and randomly, being modified."
By leveraging noise, the team found that the high-dimensional gene regulatory dynamics could be controlled instead by controlling a much smaller and simpler network, termed a "network of state transitions." In this network cells randomly transition from one phenotypic state to another -- sometimes from states representing healthy cell phenotypes to unhealthy states where the conditions are potentially cancerous. The transition paths between these states can be predicted, as cells making the same transition will typically travel along similar paths in their gene expression.
The team compares this phenomenon to the formation of pathways at a university campus. If there is no paved path between a pair of buildings, people will usually taken the path that is the easiest to traverse, tromping down the grass to reveal the dirt beneath. Eventually, campus planners may see this pre-defined path and pave it.
Similarly, upon initially analyzing a gene regulatory network the team first used noise to define the most-likely transition pathway between different system states, and connected these paths into the network of state transitions. By doing so the researchers could then focus on just one path between any two states, distilling a multi-dimensional system to a series of one-dimensional interconnecting paths.
"Even in systems as complex and high-dimensional as a gene regulatory network, there's typically only one best path that a noisy transition will follow from one state to the next," Kath said. "You would think that many different paths are possible, but that's not true: one path is much better than all of the others."
The team then developed a computational approach that can identify optimal modifications of experimentally-adjustable parameters, such as protein activation rates, to encourage desired transitions between different states. The method is ideal for experimental implementations because it changes the system's response to noise rather than changing the noise itself, which is nearly impossible to control.
