Uranus Auroras Glimpsed from Earth

For the first time, scientists have captured images of auroras above the giant ice planet Uranus, finding further evidence of just how peculiar a world that distant planet is. Detected by means of carefully scheduled observations from the Hubble Space Telescope, the newly witnessed Uranian light show consisted of short-lived, faint, glowing dots -- a world of difference from the colorful curtains of light that often ring Earth's poles.

In the new observations, which are the first to glimpse the Uranian aurora with an Earth-based telescope, the researchers detected the luminous spots twice on the dayside of Uranus -- the side that's visible from Hubble. Previously, the distant aurora had only been measured using instruments on a passing spacecraft. Unlike auroras on Earth, which can turn the sky greens and purples for hours, the newly detected auroras on Uranus appeared to only last a couple minutes.

In general, auroras are a feature of the magnetosphere, the area surrounding a planet that is controlled by its magnetic field and shaped by the solar wind, a steady flow of charged particles emanating from the sun. Auroras are produced in the atmosphere as charged solar wind particles accelerate in the magnetosphere and are guided by the magnetic field close to the magnetic poles -- that's why the Earthly auroras are found around high latitudes.

But contrary to Earth -- or even Jupiter and Saturn -- "the magnetosphere of Uranus is very poorly known," said Laurent Lamy, with the Observatoire de Paris in Meudon, France, who led the new research.

The results from his team, which includes researchers from France, the United Kingdom, and the United States, will be published on April 14 in Geophysical Research Letters, a journal of the American Geophysical Union.

Auroras on Uranus are fainter than they are on Earth, and the planet is more than 4 billion kilometers (2.5 billion miles) away. Previous Earth-bound attempts to detect the faint auroras were inconclusive. Astronomers got their last good look at Uranian auroras 25 years ago when the Voyager 2 spacecraft whizzed past the planet and recorded spectra from of the radiant display.

"This planet was only investigated in detail once, during the Voyager flyby, dating from 1986. Since then, we've had no opportunities to get new observations of this very unusual magnetosphere," Lamy noted.

Planetary scientists know that Uranus is an oddball among the solar system's planets when it comes to the orientation of its rotation axis. Whereas the other planets resemble spinning tops, circulating around the Sun, Uranus is like a top that was knocked on its side -- but still keeps spinning.

The researchers suspect that the unfamiliar appearance of the newly observed auroras is due to Uranus' rotational weirdness and peculiar traits of its magnetic axis. The magnetic axis is both offset from the center of the planet and lists at an angle of 60 degrees from the rotational axis -- an extreme tilt compared to the 11 degree difference on Earth. Scientists theorize that Uranus's magnetic field is generated by a salty ocean within the planet, resulting in the off-center magnetic axis.

The 2011 auroras differ not only from Earth's auroras but also from the Uranian ones previously detected by Voyager 2. When that spacecraft made its flyby decades ago, Uranus was near its solstice -- its rotational axis was pointed toward the Sun. In that configuration, the magnetic axis stayed at a large angle from the solar wind flow, producing a magnetosphere similar to Earth's magnetosphere, although more dynamic. Under those 1986 solstice conditions, the auroras lasted longer than the recently witnessed ones and were mainly seen on the nightside of the planet, similar to what's observed on Earth, Lamy said. Hubble can't see the far side of the planet, however, so researchers don't know what types of auroras, if any, were generated there.

The new set of observations, however, is from when the planet was near equinox, when neither end of the Uranian rotational axis aims at the Sun, and the axis aligns almost perpendicular to the solar wind flow. Because the planet's magnetic axis is tilted, the daily rotation of Uranus during the period around the equinox causes each of its magnetic poles to point once a day toward the Sun, likely responsible for a very different type of aurora than the one that was seen at solstice, Lamy explained.

"This configuration is unique in the solar system," added Lamy, who noted that the two transient, illuminated spots observed in 2011 were close to the latitude of Uranus's northern magnetic pole.

Capturing the images of Uranus's auroras resulted from a combination of good luck and careful planning. In 2011, Earth, Jupiter and Uranus were lined up so that the solar wind could flow from the Sun, past Earth and Jupiter, and then toward Uranus. When the Sun produced several large bursts of charged particles in mid-September 2011, the researchers used Earth-orbiting satellites to monitor the solar wind's local arrival two to three days later. Two weeks after that, the solar wind sped past Jupiter at 500 kilometers per second (310 miles per second). Calculating that the charged particles would reach Uranus in mid-November, the team scrambled to scheduled time on the Hubble Space Telescope.

Read more at Science Daily

Weird Super-Earths Found Orbiting Neighbor Star

Astronomers believe they have found a second distant planet around Fomalhaut, a bright young neighbor star, and that the far-out world -- like its sister planet -- is shepherding and shaping the star's ring of dust.

If confirmed, theorists have some work to do explaining how the planet, believed to be a few times bigger than Mars, ended up 155 times as far away from its parent star as Earth is to the sun.

"We're learning a lot about planets that are close to their stars, but that is not the full picture. We also want to know about systems where planets are very far out. By considering near-, far- and mid-range, we can get a complete picture of planet formation,” University of Florida astronomer Aaron Boley told Discovery News.

Of key interest is figuring out whether the planets formed in place or somehow migrated out there, bumped like celestial billiard balls after gravitational encounters with another body or bodies closer to the star.

"Whether that can actually happen is very active area of research," Boley said.

If Fomalhaut's planets are indeed ring shepherds, they’ve been on the job a long time, roughly 100 million years.

"Relative to the age of the star, they must have formed quickly," Boley added.

The suspected planet would be the second planet found orbiting Fomalhaut, a very bright star located about 25 light-years away in the constellation Piscis Austrinus. Fomalhaut is twice as big as our sun and encircled by a disk of dust 16 times wider than the span between the sun and Earth.

The inner edge of the ring is about 135 times as far as away from the star as Earth is to the sun.

The finding was made with a new telescope called ALMA, an acronym for Atacama Large Millimeter/submillimeter Array. With just 15 of its planned 66 antennas operational, astronomers already are expecting ALMA to revolutionize millimeter-wavelength astronomy, much like the Hubble Space Telescope transformed optical astronomy.

"The Fomalhaut image is just the beginning. They haven't even finished getting all of their data. This is just a sneak peak," astronomer Paul Kalas, with the University of California at Berkeley, told Discovery News.

Kalas and colleagues used Hubble Space Telescope images taken in 2004 and 2006 to pinpoint a speck of light believed to be the first direct picture of a planet in orbit around another star system. Astronomers predicted Fomalhaut had a planet smaller than Saturn inward of the ring after earlier observations showed the ring's sharp inner edge.

Read more at Discovery News

Nanoscientists Find Long-Sought Majorana Particle

Scientists at TU Delft's Kavli Institute and the Foundation for Fundamental Research on Matter (FOM Foundation) have succeeded for the first time in detecting a Majorana particle. In the 1930s, the brilliant Italian physicist Ettore Majorana deduced from quantum theory the possibility of the existence of a very special particle, a particle that is its own anti-particle: the Majorana fermion. That 'Majorana' would be right on the border between matter and anti-matter.

Nanoscientist Leo Kouwenhoven already caused great excitement among scientists in February by presenting the preliminary results at a scientific congress. Today, the scientists have published their research in Science. The research was financed by the FOM Foundation and Microsoft.

Quantum computer and dark matter

Majorana fermions are very interesting -- not only because their discovery opens up a new and uncharted chapter of fundamental physics; they may also play a role in cosmology. A proposed theory assumes that the mysterious 'dark matter', which forms the greatest part of the universe, is composed of Majorana fermions. Furthermore, scientists view the particles as fundamental building blocks for the quantum computer. Such a computer is far more powerful than the best supercomputer, but only exists in theory so far. Contrary to an 'ordinary' quantum computer, a quantum computer based on Majorana fermions is exceptionally stable and barely sensitive to external influences.

Nanowire

For the first time, scientists in Leo Kouwenhoven's research group managed to create a nanoscale electronic device in which a pair of Majorana fermions 'appear' at either end of a nanowire. They did this by combining an extremely small nanowire, made by colleagues from Eindhoven University of Technology, with a superconducting material and a strong magnetic field. "The measurements of the particle at the ends of the nanowire cannot otherwise be explained than through the presence of a pair of Majorana fermions," says Leo Kouwenhoven.

Particle accelerators

It is theoretically possible to detect a Majorana fermion with a particle accelerator such as the one at CERN. The current Large Hadron Collider appears to be insufficiently sensitive for that purpose but, according to physicists, there is another possibility: Majorana fermions can also appear in properly designed nanostructures. "What's magical about quantum mechanics is that a Majorana particle created in this way is similar to the ones that may be observed in a particle accelerator, although that is very difficult to comprehend," explains Kouwenhoven. "In 2010, two different groups of theorists came up with a solution using nanowires, superconductors and a strong magnetic field. We happened to be very familiar with those ingredients here at TU Delft through earlier research." Microsoft approached Leo Kouwenhoven to help them lead a special FOM programme in search of Majorana fermions, resulting in a successful outcome..

Read more at Science Daily

Mummified Kitten Served As Egyptian Offering

Two thousand years ago, an Egyptian purchased a mummified kitten from a breeder, to offer as a sacrifice to the goddess Bastet, new research suggests.

Between about 332 B.C. and 30 B.C. in Egypt, cats were bred near temples specifically to be mummified and used as offerings.

The cat mummy came from the Egyptian Collection of the National Archeological Museum in Parma, Italy. It was bought by the museum in the 18th century from a collector. Because of how the museum acquired it, there's no documentation about where the mummy came from.

The cat mummies from this period are common, especially kittens. "Kittens, aged 2 to 4 months old, were sacrificed in huge numbers, because they were more suitable for mummification," the authors write in the paper, published in the April 2012 issue of the Journal of Feline Medicine and Surgery.

The researchers did a radiograph — similar to an X-ray — of the mummy, to see under the wrappings, finding the small cat was actually a kitten, only about 5 or 6 months old.

"The fact that the cat was young suggests that it was one of those bred specifically for mummification," study researcher Giacomo Gnudi, a professor at the University of Parma, said in a statement.

The cat was wrapped as tightly as possible, and had been placed in a sitting position before mummification, similar to the seated cats depicted in hieroglyphics from the same era. To make the cat take up as little space as possible, the embalmers fractured some of the cat's bones, including a backbone at the base of the spine to position the tail as close to the body as possible, and ribs to make the front limbs sit closer to the body.

Read more at Discovery News

Fair-Furred Leopard is a True Pink Panther

The latest leopard fashions are in from Africa, and this year pink is hot, hot, HOT!

A male leopard in South Africa's Madikwe Game Reserve is dazzling the gawking tourists with his strawberry locks. But watch out gazelles, this fair-furred feline has still got the spots to keep him camouflaged and make him a killer when he's out on the prowl.

They say a leopard can't change his spots, but when you look as good as this pink panther, who would want to?

Perhaps the leopard took some fashion hints from Snappy the orange crocodile.

Tourists had reported seeing the fashion forward feline, but only recently Deon De Villiers, a photographer and safari guide, caught the kitty on film. He sent the photo to Panthera, a wild cat conservation group.

The light-furred leopard may have erythrism said Panthera's president Luke Hunter in National Geographic. Erythrism is a genetic condition believed to cause production of either too much red or too little dark pigment.

"It's really rare—I don't know of another credible example in leopards," said Hunter.

Read more at Discovery News

Mars Viking Robots 'Found Life'

New analysis of 36-year-old data, resuscitated from printouts, shows NASA found life on Mars, an international team of mathematicians and scientists conclude in a paper published this week.

Further, NASA doesn't need a human expedition to Mars to nail down the claim, neuropharmacologist and biologist Joseph Miller, with the University of Southern California Keck School of Medicine, told Discovery News.

"The ultimate proof is to take a video of a Martian bacteria. They should send a microscope -- watch the bacteria move," Miller said.

"On the basis of what we've done so far, I'd say I'm 99 percent sure there's life there," he added.

Miller's confidence stems in part from a new study that re-analyzed results from a life-detection experiment conducted by NASA's Viking Mars robots in 1976.

Researchers crunched raw data collected during runs of the Labeled Release experiment, which looked for signs of microbial metabolism in soil samples scooped up and processed by the two Viking landers. General consensus of scientists has been that the experiment found geological, not biological, activity.

The new study took a different approach. Researchers distilled the Viking Labeled Release data, provided as hard copies by the original researchers, into sets of numbers and analyzed the results for complexity. Since living systems are more complicated than non-biological processes, the idea was to look at the experiment results from a purely numerical perspective.

They found close correlations between the Viking experiment results' complexity and those of terrestrial biological data sets. They say the high degree of order is more characteristic of biological, rather than purely physical processes.

Critics counter that the method has not yet been proven effective for differentiating between biological and non-biological processes on Earth so it's premature to draw any conclusions.

"Ideally to use a technique on data from Mars one would want to show that the technique has been well calibrated and well established on Earth. The need to do so is clear; on Mars we have no way to test the method, while on Earth we can," planetary scientist and astrobiologist Christopher McKay, with NASA's Ames Research Center in Moffett Field, Calif., told Discovery News.

Read more at Discovery News

Significant Skull Differences Between Closely Linked Groups

In order to accurately identify skulls as male or female, forensic anthropologists need to have a good understanding of how the characteristics of male and female skulls differ between populations. A new study from North Carolina State University shows that these differences can be significant, even between populations that are geographically close to one another.

The researchers looked at the skulls of 27 women and 28 men who died in Lisbon, Portugal, between 1880 and 1975. They also evaluated the skulls of 40 women and 39 men who died between 1895 and 1903 in the rural area of Coimbra, just over 120 miles north of Lisbon.

The researchers found significant variation between female skulls from Lisbon and those from Coimbra. "The differences were in the shape of the skull, not the size," says Dr. Ann Ross, professor of anthropology at NC State and co-author of a paper describing the study. "This indicates that the variation is due to genetic differences, rather than differences of diet or nutrition." The researchers found little difference between the male skulls.

Specifically, the researchers found that the female skulls from Lisbon exhibited greater intraorbital distance than the skulls of Coimbra females. In other words, the women from Lisbon had broader noses and eyes that were spaced further apart.

This difference in craniofacial characteristics may stem from an influx of immigrants into Lisbon, which is a port city, Ross says. However, it may also be a result of preferential mate selection -- meaning Lisbon men were finding mates abroad, or were more attracted to women with those facial features.

Read more at Science Daily

'Time Machine' Will Study the Early Universe

A new scientific instrument, a "time machine" of sorts, built by UCLA astronomers and colleagues, will allow scientists to study the earliest galaxies in the universe, which could never be studied before.

The five-ton instrument, the most advanced and sophisticated of its kind in the world, goes by the name MOSFIRE (Multi-Object Spectrometer for Infra-Red Exploration) and has been installed in the Keck I Telescope at the W.M. Keck Observatory atop Mauna Kea in Hawaii.

MOSFIRE gathers light in infrared wavelengths -- invisible to the human eye -- allowing it to penetrate cosmic dust and see distant objects whose light has been stretched or "redshifted" to the infrared by the expansion of the universe.

"The instrument was designed to study the most distant, faintest galaxies," said UCLA physics and astronomy professor Ian S. McLean, project leader on MOSFIRE and director of UCLA's Infrared Laboratory for Astrophysics. "When we look at the most distant galaxies, we see them not as they are now but as they were when the light left them that is just now arriving here. Some of the galaxies that we are studying were formed some 10 billion years ago -- only a few billion years after the Big Bang. We are looking back in time to the era of the formation of some of the very first galaxies, which are small and very faint. That is an era that we need to study if we are going to understand the large-scale structure of the universe."

With MOSFIRE, it will now become much easier to identify faint galaxies, "families of galaxies" and merging galaxies. The instrument also will enable detailed observations of planets orbiting nearby stars, star formation within our own galaxy, the distribution of dark matter in the universe and much more.

"We would like to study the environment of those early galaxies," said McLean, who built the instrument with colleagues from UCLA, the California Institute of Technology and UC Santa Cruz, along with industrial sub-contractors. "Sometimes there are large clusters with thousands of galaxies, sometimes small clusters. Often, black holes formed in the centers of galaxies."

Light collected by the Keck I Telescope was fed into MOSFIRE for the first time on April 4, producing an astronomical image. Astronomers are expected to start using MOSFIRE by September, following testing and evaluation in May and June.

MOSFIRE allows astronomers to take an infrared image of a field and to study 46 galaxies simultaneously, providing the infrared spectrum for each galaxy. Currently, it can take three hours or longer to obtain a good spectrum of just one galaxy, McLean noted.

McLean built the world's first infrared camera for wide use by astronomers in 1986 and since then has built eight increasingly sophisticated infrared cameras and spectrometers -- which split light into its component colors -- as well as helping on a few others.

McLean and Charles Steidel, the Lee A. DuBridge Professor of Astronomy at the California Institute of Technology, led the project to build MOSFIRE from scratch over seven years. Harland Epps, a UC Santa Cruz professor of astronomy and astrophysics, designed the optics for the instrument. A team of nearly two dozen people helped, including Kristin Kulas and Gregory Mace, UCLA graduate students in physics and astronomy who work in McLean's laboratory; Keith Matthews, an instrument designer from Caltech; and Sean Adkins, an engineer who is the instrument program manager for the Keck Observatory in Hawaii. Most of the mechanical parts for MOSFIRE were built at UCLA and Caltech. The slit unit that enables 46 objects to be isolated was manufactured in Switzerland. The computer programming was led by UCLA.

"My father, who was an engineer, called me an astronomer by inclination, a physicist by training and an engineer by default," McLean said. "I'm an applied physicist and an astronomer."

MOSFIRE cost $14 million and likely would have cost at least twice as much if the scientists had not built it themselves, McLean estimates.

MOSFIRE was federally funded by the National Science Foundation (through the Telescope System Instrumentation program), and by Gordon and Betty Moore. Gordon Moore is co-founder, former chairman and chief executive officer, and chairman emeritus of Intel Corp.

"He is a wonderful man with a penetrating intellect," McLean said of Moore. "We are deeply indebted to him and hope to be able to show him MOSFIRE this summer."

"We had an outstanding team," he added, "with four institutions involved and many industrial partners. It was a fantastic team effort."

In the late 1990s, McLean delivered an infrared spectrometer called NIRSPEC to the Keck Observatory in Hawaii, which housed the world's largest optical and infrared telescope at the time and which contains what had been the most powerful infrared spectrometer in the world. NIRSPEC is still on the Keck II Telescope.

While NIRSPEC's camera has one megapixel, MOSFIRE has four megapixels. MOSFIRE's detectors are approximately five times more sensitive than those on NIRSPEC and about 100 times more sensitive than those from McLean's 1986 infrared camera. In addition, the digital imaging devices available today are far superior to those of 15 years ago. The result is that MOSFIRE is much more sensitive to faint objects.

Discoveries made with NIRSPEC include the detection of water on comets, insights into the stars orbiting the enormous black hole at the center of the Milky Way galaxy, and the discovery of the chemical composition of brown dwarfs. Brown dwarfs, failed stars about the size of Jupiter but with a much larger mass, are considered the "missing link" between gas giant planets like Jupiter and small, low-mass stars.

Read more at Science Daily

Tardigrade Eggs Might Survive Interplanetary Trip

Microscopic animals called tardigrades are among the few lifeforms thought capable of surviving the intense radiation, extreme temperatures and life-sucking vacuum of outer space.

Even their eggs can survive space-like conditions, hinting at the possibility of successful hatches on other planets.

“[I]f we are to assess the ability of tardigrades to survive transfer among planets or to thrive in extreme environments, they must be able to reproduce,” wrote astrobiologists who tested tardigrades in a study published April 10 in Astrobiology.

Adult tardigrades, also known as water bears, thrive in wet conditions and eat algae, bacteria or single-celled animals. If their puddles dry, they don’t die, but enter a state of total metabolic shutdown called anhydrobiosis. There they can remain for up to a decade, then spring back to life when it’s wet again.

Researchers in 2007 launched anhydrobiotic adults into orbit above Earth to see if they would survive. Those animals endured naked exposure to space for 10 days, and a few even made it through an excessive dose of ultraviolet radiation while back on Earth.

Other laboratory experiments show that adult tardigrades can survive cold near absolute zero (-459 degrees Fahrenheit), heat exceeding 300 degrees Fahrenheit, pressures dozens of times greater than at the bottom of the Marianas Trench, and intense blasts of radiation.

But what of tardigrade eggs? Some flew on the 2007 mission, but they weren’t exposed to the extreme temperatures and radiation found outside Earth’s protective magnetic shield.

To learn how the eggs would fare, NASA and astrobiologists in Japan devised three extreme stress tests for the eggs of a tardigrade species called Ramazzottius varieornatus.

In one set of tests, more than 70 percent of anhydrobiotic eggs survived temperatures as low as -320 degrees Fahrenheit and as high as 122 degrees Fahrenheit. Eggs exposed to vacuum-like conditions hatched just as well as normal eggs. Finally, more than half of anhydrobiotic eggs endured 1,690 Grays of radiation. A human would die in days if exposed to one percent of that dose.

Fully hydrated eggs, however, barely survived any of the tests.

It’s not known how tardigrade eggs survive such punishment. Whatever the mechanisms, the study’s authors think their results are good news for dried-out tardigrade families ejected into space, perhaps by an asteroid strike.

And if a few should somehow end up on, say, Mars, and be fortunate enough to find liquid water at Earth-room temperature, they might even hatch there.

Read more at Wired Science

Baboons Can Recognize Words

Baboons can learn to tell the difference between real four-letter words and nonsense combinations of letters. And once they figure out the patterns, these monkeys can guess with impressive accuracy whether a new word is real or fake.

Because baboons can’t actually read, a new study supports the theory that the brains of our primate ancestors held the necessary hardware for understanding written words long before humans evolved. Only after we starting writing and reading about 5,400 years or so did we apply our object-recognition abilities to letter symbols.

And even though we think of letters as sound units that allow us to piece words together, the new findings suggest that our brains may also view written letters like the legs on a table or the wheels on a car. Each part fits together to create an object that we recognize as a whole.

Eventually, the findings might weigh in on debates about how best to teach children to read.

“Obviously, we are using letters to get from the printed to the spoken form, and it is absolutely essential for kids to learn that this has to happen, but that’s only part of the story,” said Jonathan Grainger, a cognitive psychologist at CNRS, a national research center in Marseille, France. “The other reason we use letters in the very first phases of learning to read is that we’re basically doing what we do with ordinary everyday objects – using object parts to reconstruct the whole identity.”

“We can now look at what happens when baboons are learning words and also associating them with meaning,” he added. “We have a new paradigm that needs to be explored.”

In a large enclosure about 30 miles from Marseille, resident baboons can enter small testing booths whenever they feel like it. Inside, a computer scans a microchip embedded in each animal’s arm and launches the appropriate experiment.

For the new study, six baboons spent about six weeks learning to recognize four-letter English words on a computer screen. In 100-round trials, words came up one at a time on the screen. After tapping the word, baboons touched either an oval to indicate that it was a real word or a plus sign to signal a nonsense word.

Within each trial, a single word would come up again and again, intermixed with real words that the baboon had already learned as well as fake words. All of the words, both real and fake, contained three consonants and one vowel. For each correct answer, baboons received a food reward.

By the end of the training period, which included about 50,000 trials for each animal, all of the baboons had learned to recognize at least 81 words at an accuracy rate of about 75 percent, the researchers report today in the journal Science. One animal learned more than 300 words.

Once the baboons had boosted their vocabularies, further testing showed that the animals could often tell whether a word they had never seen before was real or fake. The more similar the fake word was to actual words, the more likely the animals were to guess that it was real, suggesting that they had learned to recognize patterns of letters that often show up in the English language.

The baboons in the experiment were not actually reading, nor did they understand that what they were looking at had symbolic meaning, said Michael Platt, a neurobiologist at Duke University in Durham, North Carolina.

Instead, the baboons’ ability to recognize letter patterns suggests that, when humans started reading and writing, they probably tapped into already existing brain circuitry that developed to recognize visual patterns.

Along with other research, the findings support a theory that alphabets look the way they do because their shapes are easily recognized by these brain systems. One implication is that dyslexia, at its root, might be a kind of visual disorder.

Read more at Discovery News