Monday, 30 August 2010

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Johnald's Fantastical Daily Link Splurge

Tiny Fridge Gets Near Absolute Zero

Posted: 30 Aug 2010 08:59 AM PDT

Annoyingly tiny fridges may not be restricted to hotels or dorm rooms much longer. A new study proposes a way to construct the smallest refrigerator yet, based on just a few particles and capable of cooling to near absolute zero.

sciencenewsThe study, which will appear in an upcoming issue of Physical Review Letters, pushes the limits of how small a cooling device can get and still remain functional.

"When thermodynamics was first invented, it was applied to big, steam engine sorts of things," says physicist Tony Short of the University of Cambridge in England, who was not involved in the study. "The fact that you can bring the ideas all the way down to individual quantum systems of tiny dimensions and the same basic ideas still work is quite nice."

Study coauthors Noah Linden, Sandu Popescu and Paul Skrzypczyk, all of the University of Bristol in England, propose a cooling scheme that relies on three linked qubits — particles that can exist in one of two states. Two of these qubits make up the refrigerator and would be held in two different heat baths: one very hot and one near room temperature. The third qubit is the object to be cooled. Because these qubits share a quantum connection, they can influence one another. So, as the hottest qubit absorbs energy from its toasty bath, it triggers the tepid qubit to siphon energy off the third qubit, cooling it. This extra energy dissipates off the second qubit in the same way the coil at the back of a refrigerator in the kitchen emits heat.

In their calculations, the physicists found that as the bath of the hottest qubit got hotter, the cooling ability of the fridge got better. And in principle, as long as the heat bath stays hot, the system can run forever. "Once you set it up, it just sits there, gently cooling away," Linden says.

Other small systems have been created, but this is the first that doesn't rely on external mechanisms, such as sophisticated lasers. "The whole guts of the fridge, it's all accounted for and not hidden in some macroscopic object which is really doing the work," Linden says.

Linden and his team also propose an even smaller system, in which a single particle with three distinct levels of quantum information, called a qutrit, acts as the refrigerator. "We believe this is the smallest possible thing you can call a fridge," Linden says.

Physicist Nicolas Gisin of the University of Geneva says the new study is "extremely elegant. It opens a totally new avenue for interesting questions, combining thermodynamics and quantum information science in a very original way."

The researchers plan to collaborate with other groups to settle on an exact blueprint for the minifridge and to build it. In the future, a tiny fridge might be used to slow or speed up reactions between proteins in cells by cooling precise parts, or to keep delicate components in quantum computers frigid.

A particularly fascinating question is whether such fridges might already exist in nature, Gisin says. For instance, a sun-drenched plant could have molecules with one end sitting directly in a natural thermal bath, allowing a tiny refrigerator to cool the other end.

Linden and his colleagues also find that idea exciting, but he's careful to point out that so far, it's just an idea. "We don't want to claim that we know of a place where this happens," he says. "But it would be great if someone came up with a molecule and said, 'Look at this. Doesn't it have the characteristics you need?' We'd be really, really happy if that happened."

Image: Flickr/ The Shopping Sherpa.

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Video: 30 Years of Asteroid Discoveries

Posted: 27 Aug 2010 11:00 AM PDT

This animation using data from observatories and amateurs around the world plots the positions of all the known asteroids in the solar system in 1980, and adds new ones as they are discovered. The pace and patterns of asteroid discovery give a neat visual illustration of the history of solar system exploration.

New asteroids appear in flashes of white, to make them easy to pick out. The final color codes for how close the object comes to Earth: Asteroids that cross Earth's orbit are shown in red, "Earth approachers" that come to 1.3 times the Earth-sun distance are yellow, and all others are green. The bunches of new asteroids follow Earth in its orbit, usually in the region directly opposite the sun (that is, in the Earth's night sky). Some clusters appear on the line between Earth and Jupiter, the side effects of surveys looking for Jovian moons.

In the mid-1990s, the pace of discovery picks up, showing the results of automated sky surveys. By 2001, the area just outside the orbit of Mars is filled in by a bright green ring of asteroids, and it keeps getting denser.

The beginning of 2010 brings a new pattern of discovery, with new asteroids fanning out on either side of the Earth. This new pattern is thanks to the Widefield Infrared Survey Explorer, an infrared space telescope that is expected to find hundreds of new asteroids by seeking their heat rather than their light.

According to the YouTube notes, "Currently we have observed over half a million minor planets, and the discovery rates snow no sign that we're running out of undiscovered objects."

The video was created using the 'astorb.dat' data created by astronomer Ted Bowell of the Lowell Observatory and colleagues.

CORRECTION: The original version of this article attributed the data to the Arecibo Observatory in Puerto Rico. It actually came from observatories all over the world, and was compiled by the Minor Planet Center and the Lowell Observatory.

Video Credit: CORRECTION: Scott Manley / Armagh Observatory / YouTube syzyg

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Weird Oblong Crater Deepens Mars Mystery

Posted: 27 Aug 2010 10:53 AM PDT

This amoeba-shaped depression on Mars, called Orcus Patera, has had planetary scientists scratching their heads for decades. Despite these sharp new images from the European Space Agency's Mars Express spacecraft, the crater's origin is a complete mystery.

Orcus Patera, discovered in 1965 by the Mariner 4 spacecraft, is located near Mars' equator, between the volcanoes Elysium Mons and Olympus Mons. At 236 miles long, it would stretch from New York to Boston on Earth. Its rim rises over a mile above the surrounding plains, and its floor lies 1,300 to 1,900 feet below its surroundings.

But in spite of lying between two volcanoes and its designation as a patera — the name for deep, complex or irregularly shaped volcanic craters — scientists aren't at all sure that Orcus Patera has a volcanic origin story. It could be a large impact crater that was originally round but later deformed by compressional forces. Or it could have formed after the erosion of aligned impact craters. The most likely explanation is that it was made in an oblique impact, when a small body struck the surface at a very shallow angle, like a rock skipping on a pond.

The new images show that the crater's rim is criss-crossed by rift-valley-like structures called graben, which are evidence for active tectonic forces in the area. Smaller graben are also visible inside the depression itself, suggesting that several tectonic events have stretched the ground. The depression also shows "wrinkle edges," which indicate that the ground has been compressed as well as stretched. The dark shapes near the center of the depression were probably formed when dark material dug up by small impacts in the depression was blown around by the wind.

But these features all appeared after Orcus Patera was formed. The oblong crater's origin is still a mystery.

Images: ESA/DLR/FU Berlin (G. Neukum). More images available on the ESA website

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Maps: How Mankind Remade Nature

Posted: 27 Aug 2010 10:30 AM PDT

As scientists get used to the idea that Earth is in a new geological age, that the Holocene — the last geological age — has been replaced by Anthropocene, they're figuring out how it got to be that way.

Two years ago, ecologists Erle Ellis and Navin Ramankutty at the University of Maryland, Baltimore County, released a map of the world's biological areas, traditionally known as biomes. Similar maps were found on science classroom walls across the land, but theirs was different in one very fundamental way: They updated the definition of biome to reflect how human beings used the land.

Ellis and Ramankutty said this was much more relevant to the 21st century, with more than six billion people using more of Earth's water, energy and matter than any other species, than classical biomes that didn't account for humanity's influence. They called their newly-defined areas "anthromes," short for anthropological biomes. It was a map for the anthropocene.

During a subsequent presentation, someone asked the researchers for details on how the anthropocene evolved. To answer that question, Ellis and Ramankutty have come out with a new set of maps that show how anthromes have changed since the beginning of the Industrial Revolution.

"You now have a biosphere that's completely transformed by people. Biology goes on in the human context, not the natural," he said. "And given the idea that most of ecosystem form and process is created by and ruled by human activity, how did it get to be that way?"

Published in the September Global Ecology and Biogeography, the maps show that in 1700, humans had already penetrated almost every habitable area. Then as now, people-free wilderness existed mostly in deserts and tundra. But in 1700, there was lots of "seminatural" land — used by people, but not heavily. Now there's little of that, and much of what remains is embedded within intensively used landscapes.

In future studies, the researchers want to overlay the anthrome map with other ecological metrics, such as biodiversity and biomass production.

The researchers' work raises philosophical and ethical questions about the difference between natural and wild, and the value of nature. In Ellis' view, the difference is irrelevant, and nature has precisely the value assigned it by people.

But whatever the answers are, "The main thing is, people need to be aware of their impacts and benefits on nature," said Ellis.

Images: 1) Global anthrome maps in 1700 and 2000./Global Ecology and Biogeography. 2) Map of land use intensity change between 1700 and 2000./Global Ecology and Biogeography. 3) Graph of global anthrome proportion change between 1700 and 2000./Global Ecology and Biogeography.

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Citation: "Anthropogenic transformation of the biomes, 1700 to 2000." By Erle C. Ellis, Kees Klein Goldewijk, Stefan Siebert, Deborah Lightman, Navin Ramankutty. Global Ecology and Biogeography, Vol. 19 No. 5, September 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Clean People Feel Morally Superior

Posted: 27 Aug 2010 10:06 AM PDT

By Olivia Solon, Wired UK

A new study shows that people feel morally cleansed when they are physically clean, and as such are more inclined to judge others more harshly.

The study, with the somewhat Victorian-sounding name of "A clean self can render harsh moral judgment" was conducted by Chen-Bo Zhong at Northwestern University and appears in the Journal of Experimental Social Psychology.

Some 58 undergrads were invited to a lab filled with spotless new equipment. Half of the students were asked to clean their hands with antiseptic wipe, so as not to soil the shiny surfaces. Afterward all the students rated the morality of six societal issues — smoking, illegal drug use, pornography, profane language, littering and adultery — on an 11-point scale ranging from very moral to very immoral. Those who'd wiped their hands made far-harsher judgments than those who didn't.

"Participants who cleansed their hands before rating the social issues judged these issues to be more morally wrong compared to those who did not cleanse their hands," the researchers report.

In a follow-up study, hundreds of participants were told to read a short passage that began, "My hair feels clean and light. My breath is fresh. My clothes are pristine and like new," made harsher moral judgments about 16 social issues compared to those primed to feel dirty by reading a passage that read, "My hair feels oily and heavy. My breath stinks. I feel so dirty."

A third study was identical to the second, except that after reading either the dirty or clean passage of text, the 136 undergrad participants also ranked themselves against their peers on several factors including intelligence, attractiveness and moral character.

Those who held a self-image of cleanliness and purity made more harsh moral judgements on social issues. Crucially, this association was entirely mediated by their having an inflated sense of moral virtue compared with their peers. (By contrast, reading the clean vs. dirty text made no difference to self -rankings on the other factors).

"Acts of cleanliness have not only the potential to shift our moral pendulum to a more virtuous self, but also license harsher moral judgment of others," Zhong and his team concluded.

Image: Flickr/Arlington County

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Ötzi the Iceman May Have Had Funeral Ceremony

Posted: 27 Aug 2010 09:35 AM PDT

A prehistoric man whose naturally mummified body was discovered frozen in the Italian Alps may have been toted up the mountain by his comrades, a new study suggests.

sciencenewsThe Iceman, also nicknamed Ötzi, lived between 5,350 and 5,100 years ago as part of a genetically distinct European population. Hikers noticed the Iceman poking out of a glacier in 1991.

Since the 2001 discovery of a stone point in the Iceman's left shoulder, many scientists have assumed that someone shot and killed Ötzi with an arrow as he attempted to flee through a mountain pass after a disastrous fight. From this perspective, the Iceman preserves a brutal prehistoric moment in time.

But a new analysis of the distribution of Ötzi's belongings around his body, published in the September issue of Antiquity, raises the possibility that he perished near kin living at low altitudes, who took him to the mountains for a final send-off as soon as the weather permitted.

Ötzi originally was placed on a group of stones that formed a platform about 20 feet uphill from the spot where hikers found him splayed in a gully, assert archaeologist Alessandro Vanzetti of the Sapienza University of Rome and his colleagues. Snow and ice that originally held the body in place partly thawed during occasional warm periods, creating a watery mix that swept the Iceman and some of his effects, including a wooden bow and copper ax, off the platform, the scientists propose.

The body then gradually rolled downhill. Lodged against a boulder in the gully, Ötzi's left arm twisted across his body at an odd angle, they assert.

"Many researchers have never questioned the 'disaster' theory of the Iceman's death, so they haven't searched for the original focus of scattering of the body and artifacts," says study co-author Luca Bondioli of the National Museum of Prehistory and Ethnography in Rome.

Archaeobotanist Klaus Oeggl of the University of Innsbruck, Austria, reported in 2000 that high concentrations of a binding material used in Ötzi's equipment appeared not just near his body but on a nearby ridge that includes the burial platform proposed by Vanzetti's team.

Oeggl agrees that warming and freezing cycles caused the Iceman's body to move from an initial resting place on the ridge to the gully. But no compelling evidence demonstrates that stones on the ridge were placed there to form a burial platform, he says.

Still, Oeggl says, "This new paper for the first time discusses a burial hypothesis in a substantial way."

Ötzi probably died in the mountains alone and close to where he suffered a fatal injury, argues biological anthropologist Albert Zink, head of the EURAC Institute for Mummies and the Iceman in Bolzano, Italy. The Iceman's joints and spine display no dislocations that would have resulted from a downhill slide. Intact blood clots in his arrow wound would show damage if the body had been carted up the mountain, Zink adds.

If Zink is correct, warming and freezing cycles should have randomly spread out his belongings, Bondioli counters. Instead, a mathematical analysis of the position of artifacts recovered around Ötzi reveals two main clumps of items, one at the proposed stone platform and another in the gully where his body lay.

A backpack frame rested on the platform, trapped by a protruding rock. Clumps of human and animal hair, plant fragments, splinters of arrow shafts and an ax lay nearby.

Remains of a grass mat, regarded as an overcoat by many investigators, were found near Ötzi's body. Vanzetti's group suspects the mat was part of a funeral shroud.

Ötzi's belongings include an unfinished wooden bow and arrow shafts lacking points, which make sense as burial offerings because a hunter could not have used them, the researchers add.

Image: Werner Nosko /Corbis.

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Lightning in Humid Regions Could Be Harvested for Energy

Posted: 27 Aug 2010 09:30 AM PDT

By Duncan Geere, Wired UK

Move over solar, wind and wave power — there's a new renewable on the block. Researchers are experimenting with devices that can pull electricity from the air.

For centuries, scientists have been fascinated by the idea of harnessing the power of thunderstorms. Nikola Tesla experimented extensively with the topic, but significant understanding of the field of atmospheric electrodynamics has until recently proved elusive.

Fernando Galembeck, of the University of Campinas in Brazil, presented a report at the 240th National Meeting of the American Chemical Society that detailed a future where every house has a device on its roof that pulls cheap, clean electricity out of the air. "Just as solar energy could free some households from paying electric bills, this promising new energy source could have a similar effect," he said.

Originally, scientists believed that water droplets in the atmosphere were electrically neutral, and remained that way even after brushing up against charges on dust particles and other liquids. However, Galembeck discovered in a series of lab experiments that water droplets do in fact pick up a charge.

He used particles of silica and aluminum phosphate, both of which are common dust particles in the air, and found that they become increasingly charged as the amount of water vapor in the air increases. "This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes into contact with," said Galembeck.

It could be possible to harvest this "hygroelectricity" from the air in regions that experience high humidity, such as the tropics. To jump-start this industry, Galembeck's team is already testing metals to see which might be of most use in capturing atmospheric electricity on hygroelectric panels.

A similar approach could help to avert lightning damage, too, by placing hygroelectric panels on buildings to take charge out of the air in the vicinity of places that suffer regular thunderstorms. "These are fascinating ideas that new studies by ourselves and by other scientific teams suggest are now possible," said Galembeck.

"We certainly have a long way to go. But the benefits in the long range of harnessing hygroelectricity could be substantial."

Image: Flickr/Bobby Dimitrov.

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Video: Dancing Parrot Boogies Better With a Partner

Posted: 27 Aug 2010 04:00 AM PDT

SEATTLE — Snowball the dancing parrot doesn't just bob to the beat. The YouTube sensation, who proved last year that humans aren't the only species that got rhythm, gets his groove on better with a dance partner.

"It's not just an automatic response to sound," said neurobiologist Aniruddh Patel of the Neurosciences Institute in San Diego. "It's concerned with bonding." Patel presented new research about the boogieing bird Aug. 24 at the International Conference on Music Perception and Cognition in Seattle, Washington.

For the famous sulfur-crested cockatoo, it's about bonding with his human caretaker, Irena Schultz. Snowball became an online celebrity in 2007 after Schultz, who runs the Bird Lovers Only Rescue Service in Indiana, put a video of him dancing to "Everybody" by the Backstreet Boys up on YouTube.

Two papers in Current Biology in May 2009 showed that Snowball — plus a total of 14 species of parrots and one species of elephant — move rhythmically to music in a way that other animals don't, demonstrating that dancing is not uniquely human. The ability to dance could come from a connection between the auditory centers and the motor centers in avian and human brains, which allows for speech and lays the foundation for synchronizing our bodies to music.

But some species of songbirds have this same neural connection — yet don't dance. Other, more social birds, like crows, sometimes synchronize their movements with their long-term mates. Patel and his colleagues wondered if Snowball's dancing has a social side.

In an experiment they called the "Dancing With Myself" test, Patel and his colleagues played music for Snowball when he was alone, when Schultz was in the room but not dancing, and when Schultz danced along with him. Naturally, the songs the team chose included Billy Idol's "Dancing With Myself," along with "Jenny (867-5309)" by Tommy Tutone and a song by Pink. The researchers tracked how much time Snowball spent dancing in each case, as well as how enthusiastic he seemed.

"We got Mack truck results," Patel said. When "Dancing With Myself" and "Jenny" played, Snowball spent about twice as much time dancing when Schultz was in the room than when he was alone, and danced more than twice as often as that when Schultz moved to the music too. For the Pink song, Snowball spent about as much time dancing alone as when Schultz was present, but again doubled his movements when Schultz joined in.

"There's some mutability here, but having a partner makes him much more likely to dance," Patel said.

In a second study, Schultz danced to a different drummer. Schultz wore headphones that played the same song Snowball heard, but at a different tempo, to see whether Snowball would follow the music or his bad dance partner.

When Schultz danced to the wrong beat, Snowball appeared confused. Eventually he turned around and ignored Schultz, dancing to his own music until close to the end of the song. When he turned to face her again, his leg-lifts were less high and his head bobs less sure. "He's less enthusiastic, more tentative," Patel said.

Unfortunately, Schultz got sick and had to postpone the study before the team could collect enough data to draw confident conclusions, Patel said. But "the bottom line is, social context matters in avian movement to music," he said. "Maybe that's why only a subset of vocal learners move rhythmically to music."

The idea "makes sense intuitively," said psychologist Charles Snowdon of the University of Wisconsin-Madison, who has studied music written specially for monkeys but was not involved in the new work. "It's a really interesting demonstration that begs for more studies."

The fact that research had to stop when Snowball's caretaker got sick — that "when the owner can't function, the bird can't function" — especially supports the idea that dancing is social for Snowball, Snowdon added. "That almost proves his point right there."

The videos from that experiment won't be available until the study is published in a scientific journal, Patel said, but Schultz and Snowball were filmed dancing together to Lady Gaga's "Bad Romance" at the Midwest Bird Expo in Illinois on May 22.

Video: Irena Schulz of Bird Lovers Only Rescue

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Live Tiger Found in Bag Full of Toy Tigers at Thai Airport

Posted: 26 Aug 2010 03:58 PM PDT

On Aug. 22, airport security officials in Bangkok detected something suspicious in an oversize suitcase. X rays indicated that along with stuffed animals, the bag contained bones. Indeed, they belonged to a tranquilized two-month-old tiger. The bag, which had been checked by a 31-year old Thai woman, had been en route to Iran.

sciencenewsThe cargo was confiscated and the cub is now under the protection of Thailand's Department of National Parks, Wildlife and Plant Conservation, according to Traffic International, a British-based conservation group committed to shutting down international trade in threatened and endangered species. DNA testing of the animal is currently underway to determine its subspecies, which may offer clues to whether it had been poached from the wild or reared in captivity.

Whatever its source, the cub could not be moved legally across national borders. The International Union for the Conservation of Nature has classified all tigers as endangered, which prohibits their movement in commercial international trade.

Bangkok's Suvarnabhumi International Airport hosts flights that move some 30 million people each year. It's also been a major hub for Asian wildlife smuggling. According to the U.S. Agency for International Development, wildlife traffickers attempted to ship more than 1,000 snakes and turtles through Suvarnabhumi, just last year alone.

The transshipment of wildlife through Bangkok is one reason U.S. AID has provided financial backing for training of security officers and police as part of a "Wildlife Trafficking Stops Here" campaign at this airport. Earlier this year, some 250 individuals took part in the training.

"Traffic is glad to see these training programs pay off in seizures, arrests and continued vigilance at the airport," notes Chris Shepherd, regional director for the conservation group in Southeast Asia. However, he adds, the fact that people think they can move wildlife through checked baggage suggests "they obviously think wildlife smuggling is something easy to get away with." The remedy, he argues, will be more-aggressive monitoring and far tougher penalties for scofflaws.

Image: Traffic

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Octopus Evades Predators by Mimicking Toxic Sea Creatures

Posted: 26 Aug 2010 03:02 PM PDT

The Indonesian mimic octopus has the boldest defense strategy of any of its cephalopod cousins, and now scientists know how that strategy evolved. Rather than blending into the scenery, the octopus mimics the swimming behavior and shape of a variety of toxic sea creatures — like flatfish and sea snakes — and displays bold color patterns that shock predators.

Scientists have reconstructed the family tree and unique evolution of the Indonesian mimic octopus, Thaumoctopus mimicus, using DNA sequences from 35 of its relatives. The study will be published in September in Biological Journal of the Linnaean Society.

For the study, scientists focused on mimic's ability to swim on the sea floor like a flatfish, of which there are several toxic varieties in the region where the octopus lives (video above). The analysis revealed that the behavior evolved in three key steps.

First, mimic octopus ancestors started switching on bold colors to shock predators when camouflage failed. Next, they learned to swim like sea-floor–dwelling fish and developed longer arms that facilitate the motion. Third, they combined the bold color patterns and flatfish swimming technique, and started doing it while out on daily forays and resting.

"While T. mimicus' imitation of a flatfish is far from perfect, it may be good enough to fool predators where it lives, in the world's center of marine diversity," biologist Healy Hamilton of the California Academy of Sciences, co-author of the study, said in a press release. "In the time it takes a predator to do a double-take, the octopus might be able to get away."

The Indonesian mimic octopus was first discovered by scientists in 1998.

The mimic octopus dispays its bold colors to ward off predators. Photo: Rich Ross

Video: Bill Macdonald Productions

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Tuesday, 24 August 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Planets Weighed Using Pulsar Flashes

Posted: 23 Aug 2010 03:43 PM PDT

The rotating corpses of massive stars can help scientists weigh the planets in the solar system. By carefully timing radio blips from spinning stellar leftovers called pulsars, astronomers have measured the masses of all the planets from Mercury to Saturn, plus all their moons and rings.

Until now, the only way to figure out the mass of a planet was to send a spacecraft past it. The spacecraft's orbit is determined by the gravitational oomph of the planet (plus whatever moons lay within the spacecraft's orbit), which in turn depends on the planet's mass. The new method is the first to let astronomers weigh planets from the comfort of Earthbound observatories.

"That's what's remarkable about this technique," said space technologist William Folkner of NASA's Jet Propulsion Laboratory, a coauthor of a study in the upcoming issue of Astrophysical Journal describing the technique. "I can't think of any other way to measure masses of planets from the Earth."

The new method relies on the clock-like regularity of a class of neutron stars called pulsars, the rapidly spinning remains of massive stars that died in supernova explosions. Pulsars shoot tight beams of radio waves into space that sweep across the sky like a lighthouse, so from Earth they appear to blink or pulse.

Because the Earth is always moving around the sun, the time it takes for these radio blips to reach us is always changing. To get rid of this effect, astronomers calculate when the pulse should reach the solar system's center of mass, or barycenter — the point around which all the mass in the solar system moves. But because the planets' arrangement around the sun is constantly changing, the barycenter moves around with respect to the sun, too.

To pin down the center of mass at a given time, astronomers use a special table of where all the planets are, called an ephemeris, plus values for the masses of the planets taken from previous space missions. If the masses are slightly wrong, then a regular, repeating pattern of timing errors appears in the pulsar data. For instance, if Jupiter's mass is a bit off, then an error appears every twelve years, once for every time Jupiter orbits the sun. Correcting the value for Jupiter's mass makes the error disappear.

"You can see that 12 year wiggle in timing of neutron stars," Folkner said. "That tells you how far the sun is from the solar system barycenter, which tells you what the mass of Jupiter is."

An international team of scientists used three different radio telescopes, the 1000-foot wide Arecibo telescope in Puerto Rico, the 210-foot Parkes telescope in Australia and the 328-foot Effelsberg telescope in Germany to time the blips from four different pulsars over a period of 5 to 22 years. They then used computer models to use the pulsars' times to calculate the masses of Mercury, Venus, Mars, Jupiter and Saturn.

The masses the team found are not as accurate as the best measurements from spacecraft flybys, but they're close. The measurement for Jupiter, for instance, was found to be 0.0009547921 times the mass of the sun. This value is more accurate than the mass determined from the Pioneer and Voyager spacecraft, and less accurate than, but consistent with, the value from the later Galileo spacecraft, which includes more decimal places.

"Our error bars are larger than those of these spacecraft measurements," said study coauthor Andrea Lommen of Franklin & Marshall College. "We are admitting freely that you should still use the mass of Jupiter measured from the spacecraft, but it's comforting to know that our measurement agrees with that."

The new method is also the first that can measure the masses of everything in a planetary system, including moons and rings.

"Spacecraft flybys don't tell us the mass of everything in the Jupiter system, only the parts inside the spacecraft orbit," Folkner said. "With this pulsar timing mechanism, we're sensitive to the entire system, including the moons that are outside the orbit of any spacecraft that have flown by."

The technique is actually a stepping stone to studying something even more exotic: ripples in spacetime called gravitational waves that were predicted by Einstein but have never been observed. The timing of pulsar blips should change slightly whenever a gravitational wave goes by, but in order to see these changes, astronomers have to subtract out all the other noise that could alter the pulsar's clock.

This study is "a graphic demonstration that you really have to understand the solar system really well if you're going to be able to confidently detect gravitational radiation," commented astronomer Scott Tremaine of the Institute for Advanced Study in Princeton, NJ, who was not involved in the new work. "If they can continue to develop these techniques to the point where they can detect gravitational waves, that will be a dramatically important event."

Image: The sun, Earth and Jupiter orbit a common center of mass. David Champion, MPIfR

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Vault Freezes Coral Cells to Preserve Them From Extinction

Posted: 23 Aug 2010 11:55 AM PDT

In an effort to preserve the biodiversity of Hawaiian coral species, scientists at the University of Hawaii have created the first frozen coral cell bank — similar in concept to a seed bank for plants.

"Because frozen banked cells are viable, the frozen material can be thawed in one, 50 or, in theory, even 1000 years from now to restore a species or population," said biologist Mary Hagedorn of the University of Hawaii in a press release. "In fact, some of the frozen sperm samples have already been thawed and used to fertilize coral eggs to produce developing coral larvae."

Summer interns, Malia Paresa and Kelly Martonrana, place coral into the frozen repository.

Coral reefs are disappearing at an alarming rate due to warming, acidifying oceans and other types of human impact. Just last week, scientists reported that a spike in ocean temperatures off the coast of Indonesia is causing the most massive die-off ever seen in the region, already killing 80 percent of the coral species on several reefs. These types events are expected to get more frequent across the globe, with some scientists warning extinction of coral reefs is eminent within the next century.

Coral reefs cover less than a tenth of the ocean's surface but are home to a quarter of all marine species. Corals enable this diversity by building complex structures where many creatures can live and hide.

Globally, there are approximately 1000 known reef-building coral species. Corals are primitive animals most closely related to jellyfish. The types of coral that build reefs get their color and most of their energy from symbiotic algae living within their cells. When water temperatures get hotter than corals they experience coral bleaching, where they expel their symbiotic algae, turn bleach white, and often die.

One of the other major factors threatening coral reefs is the oceans becoming more acidic from increased carbon dioxide in the atmosphere. In more acidic water corals have difficulty secreting their reef-building calcium carbonate shell.

So far, the Hawaiian coral cell bank has frozen sperm and embryotic cells from mushroom coral (Fungia scutaria) and rice coral (Montipora capitata). They aim to store as many species of Hawaiian coral as possible.

The work is being funded by the Smithsonian, University of Hawaii, Morris Animal Foundation, and Anela Kolohe Foundation.

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Images: 1) Fungia, one of the corals deposited into the frozen repository. Ann Farrell/ Hawaii Institute of Marine Biology at the University of Hawaii. 2) Hawaii Institute of Marine Biology at the University of Hawaii.

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Danish Volunteers Build Manned Spacecraft

Posted: 23 Aug 2010 08:29 AM PDT

A team of Danish volunteers has built a rocket capable of carrying a human into space, and will be launching it in a week's time. The project, which has been funded entirely by donations and sponsorship, is led by Kristian von Bengtson and Peter Madsen.

The rocket is named HEAT1X-TYCHO BRAHE, and its first test flight will carry a crash-test dummy, rather than a human, so that the safety aspects of the design can be analyzed. It'll launch from a floating platform that the team has also built, which will be towed into the middle of the Baltic Sea by a submarine called Nautilus that the pair built as their last project.

The creators are members of the SomethingAwful web community, and have been posting pictures and answering questions there. In response to one question asking what the chances of the person inside dying are, they replied: "Unlike Columbia we're not moving at orbital speeds so 'dying a gruesome death burning up on re-entry' with our kit has a very low outcome probability."

Despite that, the rocket will still break the sound barrier, and subject the pilot (who is forced to stand inside the capsule) to considerable g-forces. As a result, the astronaut will only be able to move his arms, which will be able to operate a camera, the manual override functionality, the exit hatch, an additional oxygen mask and a vomit bag.

When the rocket hits the team's original target suborbital altitude of 150,000 meters (almost 500,000 feet, approximately 93 miles) and begins to descend again, parachutes will slow it and the team will track it with a GPS link and a "fast boat". The team said: "We should be able to receive a descent plot which can be used in projecting a splashdown ellipse pretty accurately, if we factor in wind speeds and so on."

The first test launch is slated for Aug. 31. The crew will set off from Denmark the previous day, as it takes about 36 hours of sailing to reach the site. The team's website is down at the time of writing, presumably due to the attention the launch is generating, but can be found at

If successful, Denmark will be the fourth country to put one of its citizens into space, following the United States, Soviet Union and China, and the first in the world to do it without government funding.

Image: Frumpykvetchbot

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Monday, 23 August 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Magnificent Marine Algae Blooms Seen From Space

Posted: 23 Aug 2010 04:00 AM PDT

<< previous image | next image >>

When microscopic marine organisms known as phytoplankton multiply into a dense population at the ocean's surface, massive blooms can spread so far that they can only be seen from space. These algal blooms create beautiful patterns that can stretch for hundreds of miles and trace the ocean's swirling currents.

Phytoplankton are the foundation of the ocean food web and are critical to the health of nearly everything that lives there. They contain chlorophyll to perform photosynthesis and turn sunlight into energy which feeds their predators, and their predators' predators, all the way up through the food chain to large fish, mammals and birds such as sharks, sea lions and penguins.

Recent research suggests the fear that warming oceans could hamper phytoplankton growth may be real. The organisms depend on mixing of ocean water to bring nutrients such as phosphates and nitrates to the surface. As the ocean warms, it becomes more stratified, with the warmer water remaining at the top where the organisms need to be in order to do photosynthesis.

A big reduction in phytoplankton could threaten marine animals and the fisheries humans depend on. And it could create a climate feedback loop that would increase temperatures further. These organisms absorb carbon dioxide from the atmosphere and take it to the bottom of the ocean when they die, where it stays for thousands of years. So as their numbers decline, they will do less to keep global temperatures down.

In addition to capturing amazing images of the phytoplankton blooms, satellite data is one of the only ways to study them. Different species of phytoplankton change the way the ocean reflects light in different ways. The chlorophyll in the tiny organisms causes the ocean's surface to reflect green. Other pigments can make the water look red or brown. Some phytoplankton called coccolithophores are coated with white calcite that makes the water look bright turquoise when billions of them get together.

More on phytoplankton from NASA's Earth Observatory.

Click on any image in this gallery for a high-res version.


The large, beautiful bloom pictured above off the coast of Ireland on May 22, 2010 was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. The phytoplankton may have benefited from iron and nutrients in the ash dumped onto the ocean surface for weeks by Iceland's Eyjafjallajökull Volcano.

Previously, scientists found that the 2008 eruption of the Kasotochi Volcano in the Aleutian Islands fertilized the ocean and caused a huge phytoplankton bloom in the northern Pacific Ocean.

Below, the Terra satellite imaged another brilliant bloom in the area on June 4, 2007. The bloom emanates from the mouth of the River Shannon and tapers off to the north.

Images: 1) Jeff Schmaltz, MODIS Rapid Response Team/NASA. 2) MODIS Rapid Response Team/NASA.

The Precarious Future of Ocean Color Satellite Imagery

Posted: 23 Aug 2010 02:00 AM PDT

NPP satellite getting prepped on earth.

The United States owns three orbiting satellites capable of measuring plant life in the world's oceans, and they're all on their last legs. That has ocean scientists pushing NASA to have its next satellite take an occasional look at the moon, a critical step for transmitting accurate images of the sea.

The three satellites, SeaWiFS, Aqua and Terra, have been flying far longer than they were designed to. SeaWiFs, for example, was built to last three to five years but has lasted 13. Critically, all of these satellites look at the moon on a monthly basis to calibrate the ocean color sensors, which degrade over time.

"If you're looking at long-term changes, you need to know how your instrument is changing," said Charles McClain, chief scientist of the SeaWiFS mission. "The best way to do that is to roll the space craft a little bit to look at the moon. It's easy to do, but it interferes with operations. We've put a request in for NPP to it, but it hasn't been approved."

NPP is the National Polar Orbiting Environmental Satellite System Preparatory Project, a joint NASA, Department of Defense and National Oceanic and Atmospheric Administration mission scheduled to launch in 2011.

If NPP doesn't get accurate measurements of ocean color, which are used to measure the amount of chlorophyll from plants in the surface ocean, the next scheduled satellite mission that will be capable of doing so is PACE. But that mission isn't scheduled until 2018, McClain said.

Keeping track of the amount of plant life in the ocean has become increasingly important for scientists researching global climate change and how ocean plants act as a carbon sink. Politically, getting NPP to do the necessary moon checkup is challenging because it's an operational satellite, meaning its primary objective is accurate weather forecasting and climate science.

"Operational and science satellites are different," said atmospheric scientist Leo Andreoli, chief scientist at Northrop Grumman Aerospace Systems. Northrop is a subcontractor building and testing the main sensor, called the Visible Infrared Radiometer Suite, on the NPP. "Operational satellites have to be replaced and have follow-ons, whereas scientific missions go up to see what they can see, and don't necessarily have to have a follow on."

"This is really gravy for them, having their science collected on an operational satellite," Andreoli added.

Despite being "gravy," Andreoli said, getting ocean color always has been part of the NPP mission, and getting ocean color from any satellite is tough. In 2008, they didn't think the sensor on NPP would be capable of it, but Andreoli said they've worked out algorithms and mathematical procedures to correct the problems with the sensor.

When it comes to looking at the moon for calibration, though, Andreoli says he's not sure the request will go through.

"I will say that being in the operation of satellites for many years that one does not like to take the satellite and turn it away from the earth because there is a risk you won't be able to get it to turn back," he said. "It needs to be weighed against the value of the mission."

So the future remains precarious for ocean scientists. In a best-case scenario, NPP will be able to get accurate measurements of chlorophyll and will serve as a backup when SEAWiFS, Aqua and Terra inevitably die.

In a worst case scenario, there will be a gap in the data until PACE goes up in 2018, which will calculate chlorphyll but also have the spectral coverage to explore new science objectives, McClain said.

Image: 1) Phytoplankton bloom off the coast of Newfoundland taken August 9, 2010. Jeff Schmaltz/MODIS Rapid Response Team. 2) Ball Aerospace

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Our Solar System: Now With 2 Million Years More Maturity

Posted: 23 Aug 2010 02:00 AM PDT

New measurements of an old rock show that the solar system may be up to two million years older than scientists previously thought. The new birth date could resolve a major controversy among geochemists, and provides extra evidence that the solar system got its heavy elements from the explosion of a nearby supernova.

The currently accepted age of the solar system — about 4.56 billion years — was calculated by measuring parts of meteorites called calcium-aluminum-rich inclusions, which are thought to be the first solids to have condensed from the cloud of gas that formed the sun and planets.

The inclusions' ages come from measuring how much of certain radioactive isotopes, versions of the same element that have different atomic masses, and their decay products are in the rock. Because a parent isotope decays into a daughter isotope at a set rate, scientists can work backwards to get an age for the rock by comparing the amounts of these isotopes.

Each set of parent and daughter isotopes ought to give the same age for the solar system — but they don't. Tests comparing the relative amounts of aluminum and magnesium give ages about one million years older than tests comparing two different isotopes of lead. Resolving the difference is "one of the major problems in cosmochemistry today," according to geophysicist Andrew Davis of the University of Chicago.

One possible explanation is that earlier experiments used an impure rock. Much of the earlier work used inclusions from one meteorite called Allende, whose inclusions are relatively large and easy to analyze.

"That particular meteorite is fairly messed up," said cosmochemist Meenakshi Wadhwa of Arizona State University, a coauthor of a study in the August 22 Nature Geoscience reporting the new solar system age. The Allende meteorite melted and re-cooled at least once after it was formed on its parent asteroid, so the ages it gives "may not be as reliable."

So Wadhwa and Arizona State geochemist Audrey Bouvier found a more pristine rock to study. They used an inclusion from a three-pound meteorite called NWA 2364, which was found in Morocco in 2004 and appears to have remained unchanged since it formed.

"This meteorite is thus extremely rare and precious for the inclusions that it contains," Bouvier said.

Bouvier and Wadhwa subjected the inclusion to all kinds of violence, like repeatedly washing it with acid and dissolving the pieces in a solution of hydrogen fluoride and nitric acid, to remove any earthly contaminants and isolate the radiogenic elements. They measured the relative amounts of two isotopes of lead, lead-206 and lead-207. These lead isotopes come from the decay of two different versions of uranium, uranium-238 and uranium-235. Because uranium decays relatively quickly, and because the method compares two different isotopes at once, lead-lead dating is considered one of the best ways to age rocks.

"The dates with this chronometer are more precise than anything you can get from any other chronometer," Wadhwa said.

The researchers also considered new evidence that a classic equation used for lead-lead dating needs an update. In an earlier paper, Wadhwa and colleagues at Arizona State showed that a common assumption geochronologists make when finding rocks' ages — that certain types of uranium always appear in the same relative quantities in meteorites — is wrong.

Although they couldn't actually measure the different amounts of uranium in the meteorite, "we tried to take into account the possibility that you might have a different uranium composition than was assumed," Wadhwa said.

Bouvier and Wadhwa found that the meteorite inclusion formed 4,568.2 million years ago, between 0.3 and 1.9 million years earlier than the next best lead-lead measurements suggest. They also tested the relative amounts of aluminum and magnesium in the rock, and found the same exact age, resolving the difference found in earlier studies.

"This is an excellent and important study," commented Davis, who was not involved in the study. But it does raise some questions: What was wrong with Allende? Can the age be refined even further by actually measuring the uranium ratios? "It is important to measure ages on more calcium-aluminum-rich inclusions" in the future, Davis said.

To a 4.5 billion year old solar system, two million years might not sound like much. But it makes a big difference for understanding how the infant solar system formed, Wadhwa said.

"Most of what shaped the formation history of the solar system, and the planets and asteroids and all that, a lot of that happened within the first 5 to 10 million years," she said. "Being able to actually pinpoint to within something like 2 million years what the age of the solar system is does make a difference in terms of trying to resolve the sequence of events that happened subsequently."

The new age also means that some radioactive elements were much more abundant in the early solar system than previously thought. In particular, the new age suggests that there would be twice as much iron-60 in the early solar system.

"That kind of abundance can't be produced by anything but a supernova," Wadhwa said.


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