An Infant Star System With 'Thousands of Oceans' Worth of Water
|3:26:21 AM, Friday, October 28, 2011|
"Astrophysicists have detected the first signs of cold water vapor in the outer reaches of a baby star system. The discovery, announced today in Science, not only fills a gap in the convoluted question of how planets form, but also hints where the water that covers Earth-like planets is stored until the rocky bodies can receive and hold onto it as oceans.
The short version of how scientists believe the Earth formed goes like this: Roughly 4.5 billion years ago, the solar system was a spinning disk of gas and dust that looked something like a record, and one groove in that record collapsed into a molten orb that became our planet. About 700 million years later, when Earth was crusty and dried-out, comets, asteroids and other watery space wanderers bombarded the world. In just tens or hundreds of thousands of years, these impacts deposited our life-giving water.
The question is where all that water came from. For decades, astrophysicists have suspected that the water in these small icy bodies originated in the center of the freezing-cold outer zone of planet-forming disks. Yet the water’s temperature—just above absolute zero—made it virtually impossible to detect, preventing scientists from confirming their suspicion.
But now a team of researchers has seen the signs. Using the Herschel Space Observatory, scientists have spied faint signature of water on the surface of an expansive and chilly region of a planet-forming disk spinning around the star TW Hydrae. The extremely faint finding is probably the tip of a colossal celestial iceberg, as a store of water amounting to thousands of Earth oceans probably hides in the center of the disk.
"We now have a glimpse at a very early stage in planetary systems we had only hypothesized to exist," says space scientist Diane Wooden of NASA Ames Research Center, who was not involved in the study. "This has been an extremely difficult signature to find."
The Search for Ice
TW Hydrae, located 175 light-years away from Earth, is between 5 million and 10 million years old. Compared with the 4.5-billion-year-old sun of ours, it’s practically an infant. The star is so young and so close to Earth that scientists look to it for a picture of what our own solar system looked like in its early years. Most captivating of all is TW Hydrae’s spinning disk of gas, dust, water and other planet-building materials; it stretches 200 astronomical units (AU) from the star (one AU is the sun-to-Earth distance). By comparison, the dwarf planet Pluto at its farthest orbital distance is only 49 AU from the sun.
But it’s not easy to find ice, even around a well-studied star. Water is easier to find when it’s hot, because water vapor emits strong signals that instruments called spectrometers can detect. TW Hydrae is hot enough to thaw the ice in the part of its planet-forming disk that’s within three to five AU, so astronomers can see that easily. However, beyond TW Hydrae’s three to five AU border, called the snow line, the signal fades because water freezes. Scientists who’d looked at the TW Hydrae system before couldn’t detect that distant ice, and estimate how much of it might be around to form comets later in the star system’s life.
In May 2009, astronomers got a new tool when the European Space Agency (ESA) launched the Herschel Space Observatory, an orbiting telescope designed to pick up the faintest signals from the coldest objects in space. The team behind this study, led by astrophysicist Michiel Hogerheijde of Leiden University in the Netherlands, pointed Herschel at TW Hydrae and opened the shutter for 18 hours.
"Before Herschel, this was simply not feasible. You have to get outside Earth’s atmosphere to see the water, so you go to space," Hogerheijde says. "The other space telescopes were not sensitive enough."
Although TW Hydrae’s disk is extremely cold beyond 100 AU (just 20 degrees above absolute zero), a weak influx of ultraviolet and X-ray light both from TW Hydrae and nearby stars can form fleeting water vapor molecules. When a molecule of water ice absorbs one of these wavelengths’ photons, the molecule’s two hydrogen and one oxygen atoms split into one hydrogen and one oxygen-hydrogen molecule. They quickly recombine, but Herschel can see the faint infrared radiation they emit (if it stares long enough, that is).
"It’s like when you put an aluminum ball in the microwave. The microwave beam liberates electrons from the aluminum, which we see as sparks," Hogerheijde says.
To the team’s surprise, the cold water vapor signal was three to five times weaker than expected. Yet by comparing the result to a laboratory benchmark, they estimated the icy grains deep inside the disk harbor as much water as 6500 Earth oceans..."
First Google.org-Funded Geothermal Mapping Report Confirms Vast Coast-To-Coast Clean Energy Source
|9:46:10 PM, Tuesday, October 25, 2011|
"New research from SMU's Geothermal Laboratory, funded by a grant from Google.org, documents significant geothermal resources across the United States capable of producing more than three million megawatts of green power – 10 times the installed capacity of coal power plants today.
Sophisticated mapping produced from the research, viewable via Google Earth at http://www.google.org/egs/, demonstrates that vast reserves of this green, renewable source of power generated from the Earth's heat are realistically accessible using current technology.
The results of the new research, from SMU Hamilton Professor of Geophysics David Blackwell and Geothermal Lab Coordinator Maria Richards, confirm and refine locations for resources capable of supporting large-scale commercial geothermal energy production under a wide range of geologic conditions, including significant areas in the eastern two-thirds of the United States. The estimated amounts and locations of heat stored in the Earth's crust included in this study are based on nearly 35,000 data sites – approximately twice the number used for Blackwell and Richards' 2004 Geothermal Map of North America, leading to improved detail and contouring at a regional level.
Based on the additional data, primarily drawn from oil and gas drilling, larger local variations can be seen in temperatures at depth, highlighting more detail for potential power sites than was previously evident in the eastern portion of the U.S. For example, eastern West Virginia has been identified as part of a larger Appalachian trend of higher heat flow and temperature.
Conventional U.S. geothermal production has been restricted largely to the western third of the country in geographically unique and tectonically active locations. For instance, The Geysers Field north of San Francisco is home to more than a dozen large power plants that have been tapping naturally occurring steam reservoirs to produce electricity for more than 40 years.
However, newer technologies and drilling methods can now be used to develop resources in a wider range of geologic conditions, allowing reliable production of clean energy at temperatures as low as 100˚C (212˚F) – and in regions not previously considered suitable for geothermal energy production. Preliminary data released from the SMU study in October 2010 revealed the existence of a geothermal resource under the state of West Virginia equivalent to the state's existing (primarily coal-based) power supply.
"Once again, SMU continues its pioneering work in demonstrating the tremendous potential of geothermal resources," said Karl Gawell, executive director of the Geothermal Energy Association. "Both Google and the SMU researchers are fundamentally changing the way we look at how we can use the heat of the Earth to meet our energy needs, and by doing so are making significant contributions to enhancing our national security and environmental quality."
"This assessment of geothermal potential will only improve with time," said Blackwell. "Our study assumes that we tap only a small fraction of the available stored heat in the Earth's crust, and our capabilities to capture that heat are expected to grow substantially as we improve upon the energy conversion and exploitation factors through technological advances and improved techniques."
Blackwell is scheduled to release a paper with details of the results of the research to the Geothermal Resources Council in October 2011.
Blackwell and Richards first produced the 2004 Geothermal Map of North America using oil and gas industry data from the central U.S. Blackwell and the 2004 map played a significant role in a 2006 Future of Geothermal Energy study sponsored by the U.S. Department of Energy that concluded geothermal energy had the potential to supply a substantial portion of the future U.S. electricity needs, likely at competitive prices and with minimal environmental impact. SMU's 2004 map has been the national standard for evaluating heat flow, temperature and thermal conductivity for potential geothermal energy projects.
In this newest SMU estimate of resource potential, researchers used additional temperature data and in-depth geological analysis for the resulting heat flow maps to create the updated temperature-at-depth maps from 3.5 kilometers to 9.5 kilometers (11,500 to 31,000 feet). This update revealed that some conditions in the eastern two-thirds of the U.S. are actually hotter than some areas in the western portion of the country, an area long-recognized for heat-producing tectonic activity. In determining the potential for geothermal production, the new SMU study considers the practical considerations of drilling, and limits the analysis to the heat available in the top 6.5 km (21,500 ft.) of crust for predicting megawatts of available power. This approach incorporates a newly proposed international standard for estimating geothermal resource potential that considers added practical limitations of development, such as the inaccessibility of large urban areas and national parks. Known as the 'technical potential' value, it assumes producers tap only 14 percent of the 'theoretical potential' of stored geothermal heat in the U.S., using currently available technology...
Artificial Intelligence Community Mourns John McCarthy
|9:30:33 PM, Tuesday, October 25, 2011|
"Artificial intelligence researcher, John McCarthy, has died. He was 84.
The American scientist invented the computer language LISP.
It went on to become the programming language of choice for the AI community, and is still used today.
Professor McCarthy is also credited with coining the term "Artificial Intelligence" in 1955 when he detailed plans for the first Dartmouth conference. The brainstorming sessions helped focus early AI research.
Prof McCarthy's proposal for the event put forward the idea that "every aspect of learning or any other feature of intelligence can in principle be so precisely described that a machine can be made to simulate it".
The conference, which took place in the summer of 1956, brought together experts in language, sensory input, learning machines and other fields to discuss the potential of information technology.
Other AI experts describe it as a critical moment.
"John McCarthy was foundational in the creation of the discipline Artificial Intelligence," said Noel Sharkey, Professor of Artificial Intelligence at the University of Sheffield.
"His contribution in naming the subject and organising the Dartmouth conference still resonates today."
Prof McCarthy devised LISP at Massachusetts Institute of Technology (MIT), which he detailed in an influential paper in 1960.
The computer language used symbolic expressions, rather than numbers, and was widely adopted by other researchers because it gave them the ability to be more creative.
"The invention of LISP was a landmark in AI, enabling AI programs to be easily read for the first time," said Prof David Bree, from the Turin-based Institute for Scientific Interchange.
"It remained the AI language, especially in North America, for many years and had no major competitor until Edinburgh developed Prolog."
RegretsIn 1971 Prof McCarthy was awarded the Turing Award from the Association for Computing Machinery in recognition of his importance to the field.
He later admitted that the lecture he gave to mark the occasion was "over-ambitious", and he was unhappy with the way he had set out his new ideas about how commonsense knowledge could be coded into computer programs.
However, he revisted the topic in later lectures and went on to win the National Medal of Science in 1991..."
2,000-Year-Old Supernova Mystery Solved By NASA Telescopes
|8:39:18 PM, Tuesday, October 25, 2011|
"Two NASA space telescopes have helped solve some of the most enduring mysteries of the first documented report of star explosion — an ancient supernova spotted nearly 2,000 years ago, scientists say.
In 185 A.D., Chinese astronomers witnessed what they called a mysterious "guest star" that appeared in the sky and lingered for about eight months. It wasn't until the 1960s that scientists determined that this cosmic object was the first documented observation of a supernova that signaled the violent death of a distant star.
Now, infrared views of the supernova from NASA's Spitzer Space Telescope and the Wide-field Infrared Survey Explorer (WISE) reveal that the star explosion detonated inside a region of space that was relatively free of gas and dust. This allowed the star's explosion to travel out much farther and faster than expected, researchers said.
"This supernova remnant got really big, really fast," said Brian Williams, an astronomer at North Carolina State University in Raleigh, in a statement. "It's two to three times bigger than we would expect for a supernova that was witnessed exploding nearly 2,000 years ago. Now, we've been able to finally pinpoint the cause."
Williams is the lead author of the new study, which is detailed online in the Astrophysical Journal.
The ancient supernova, called RCW 86, is located about 8,000 light-years from Earth. But while its location was known, much of its details were shrouded in mystery.
One enigma is the fact that the star's spherical remains are larger than expected. If the star's exploded guts could be seen in infrared light in the sky today, they ywould take up more space than the full moon, researchers said.
By combining the new data from Spitzer and WISE with existing information from NASA's Chandra X-Ray Observatory and the European Space Agency's XMM-Newton Observatory, astronomers were able to grasp the missing pieces of the puzzle.
They found that RCW 86 is a so-called Type Ia supernova, triggered by the relatively peaceful death of a star similar to our sun. This star shrank into a dense star called a white dwarf before siphoning matter, or fuel, from a nearby companion star. The white dwarf is then thought to have exploded in a brilliant supernova explosion.
"A white dwarf is like a smoking cinder from a burnt-out fire," Williams said. "If you pour gasoline on it, it will explode."
The study showed for the first time that a white dwarf can create a cavitylike empty region of space around itself before exploding in a Type Ia supernova event. The presence of a cavity would explain why the remnants of RCW 86 are so big, researchers said.
When the explosion occurred, the cavity would have allowed the resulting ejected material to spew out unimpeded by gas and dust. This would also have allowed the star's remains to be cast out rapidly..."
Official: Formula 1 Race Coming to NJ in 2013
|5:37:17 PM, Tuesday, October 25, 2011|
"WEEHAWKEN, N.J. (AP) — An official with direct knowledge of the plan says Formula One is coming to New Jersey in June 2013 with a race on the Hudson River shoreline just minutes from New York City.
The person says the Grand Prix event will take place in Weehawken and West New York, with the Manhattan skyline as a backdrop. The person spoke to The Associated Press on the condition of anonymity Monday because the race has yet to be announced. A press conference is scheduled in Weehawken on Tuesday, and will likely be attended by New Jersey governor Chris Christie.
The U.S. hasn't hosted a Formula One race since 2007 in Indianapolis, an event won by Lewis Hamilton.
A race is scheduled for Austin, Texas, in 2012.
The race could mean a big boost to the economy in North Jersey, which typically benefits from national and international events at the Meadowlands Sports Complex, where the NFL's New York Giants and Jets play. But although the Super Bowl is coming to MetLife Stadium there in 2014, the complex has sagged a bit economically with the loss of the NHL's New Jersey Devils and NBA's New Jersey Nets to the nearby Prudential Center in Newark.
The tentative name for the race is the Formula 1 Grand Prix of America.
The area is not foreign to motorsports, though it has been awhile. The Meadowlands Grand Prix was a CART IndyCar race held in East Rutherford from 1984-1991. It was the first major race in the New York City metropolitan area since 1937, and the course twisted and turned around the original Giants Stadium.
The Formula One race would likely stroll through River Road, which runs alongside the Hudson River, allowing for clear views of the New York City skyline. It would also offer fans and tourists easy accessibility to New York City lodging, restaurants and nightlife, though they could also easily stay in Hudson County, as well."
Archaeologists Find Blade Production Earlier Than Originally Thought
|10:06:17 PM, Monday, October 24, 2011|
"Archaeology has long associated advanced blade production with the Upper Palaeolithic period, about 30,000-40,000 years ago, linked with the emergence of Homo Sapiens and cultural features such as cave art. Now researchers at Tel Aviv University have uncovered evidence which shows that "modern" blade production was also an element of Amudian industry during the late Lower Paleolithic period, 200,000-400,000 years ago as part of the Acheulo-Yabrudian cultural complex, a geographically limited group of hominins who lived in modern-day Israel, Lebanon, Syria and Jordan.
Prof. Avi Gopher, Dr. Ran Barkai and Dr. Ron Shimelmitz of TAU's Department of Archaeology and Ancient Near Eastern Civilizations say that large numbers of long, slender cutting tools were discovered at Qesem Cave, located outside of Tel Aviv, Israel. This discovery challenges the notion that blade production is exclusively linked with recent modern humans.
The blades, which were described recently in the Journal of Human Evolution, are the product of a well planned "production line," says Dr. Barkai. Every element of the blades, from the choice of raw material to the production method itself, points to a sophisticated tool production system to rival the blade technology used hundreds of thousands of years later.
An innovative product
Though blades have been found in earlier archaeological sites in Africa, Dr. Barkai and Prof. Gopher say that the blades found in Qesem Cave distinguish themselves through the sophistication of the technology used for manufacturing and mass production.
Evidence suggests that the process began with the careful selection of raw materials. The hominins collected raw material from the surface or quarried it from underground, seeking specific pieces of flint that would best fit their blade making technology, explains Dr. Barkai. With the right blocks of material, they were able to use a systematic and efficient method to produce the desired blades, which involved powerful and controlled blows that took into account the mechanics of stone fracture. Most of the blades of were made to have one sharp cutting edge and one naturally dull edge so it could be easily gripped in a human hand.
This is perhaps the first time that such technology was standardized, notes Prof. Gopher, who points out that the blades were produced with relatively small amounts of waste materials. This systematic industry enabled the inhabitants of the cave to produce tools, normally considered costly in raw material and time, with relative ease.
Thousands of these blades have been discovered at the site. "Because they could be produced so efficiently, they were almost used as expendable items," he says.
Prof. Cristina Lemorini from Sapienza University of Rome conducted a closer analysis of markings on the blades under a microscope and conducted a series of experiments determining that the tools were primarily used for butchering..."
Rapidly Inflating Volcano Creates Growing Mystery
|10:00:32 PM, Monday, October 24, 2011|
"Should anyone ever decide to make a show called "CSI: Geology," a group of scientists studying a mysterious and rapidly inflating South American volcano have got the perfect storyline.
Researchers from several universities are essentially working as geological detectives, using a suite of tools to piece together the restive peak's past in order to understand what it is doing now, and better diagnose what may lie ahead.
It's a mystery they've yet to solve.
Uturuncu is a nearly 20,000-foot-high (6,000 meters) volcano in southwest Bolivia. Scientists recently discovered the volcano is inflating with astonishing speed.
"I call this 'volcano forensics,' because we're using so many different techniques to understand this phenomenon," said Oregon State University professor Shan de Silva, a volcanologist on the research team.
Researchers realized about five years ago that the area below and around Uturuncu is steadily rising — blowing up like a giant balloon under a wide disc of land some 43 miles (70 kilometers) across. Satellite data revealed the region was inflating by 1 to 2 centimeters (less than an inch) per year and had been doing so for at least 20 years, when satellite observations began.
"It's one of the fastest uplifting volcanic areas on Earth," de Silva told OurAmazingPlanet."What we're trying to do is understand why there is this rapid inflation, and from there we'll try to understand what it's going to lead to."
The peak is perched like a party hat at the center of the inflating area. "It's very circular. It's like a big bull's-eye," said Jonathan Perkins, a graduate student at the University of California, Santa Cruz, who recently presented work on the mountain at this year's Geological Society of America meeting in Minneapolis.
Scientists figured out from the inflation rate that the pocket of magma beneath the volcano was growing by about 27 cubic feet (1 cubic meter) per second.
"That's about 10 times faster than the standard rate of magma chamber growth you see for large volcanic systems," Perkins told OurAmazingPlanet.
However, no need to flee just yet, the scientists said.
"It's not a volcano that we think is going to erupt at any moment, but it certainly is interesting, because the area was thought to be essentially dead," de Silva said..."
Up to 20 Million Tons of Debris from Japan’s Tsunami Moving Toward Hawaii
|9:57:16 PM, Monday, October 24, 2011|
"Some 5 to 20 million tons of debris--furniture, fishing boats, refrigerators--sucked into the Pacific Ocean in the wake of Japan's March 11 earthquake and tsunami are moving rapidly across the Pacific. Researchers from the University of Hawaii tracking the wreckage estimate it could approach the U.S. West Coast in the next three years, the UK Daily Mail reports.
"We have a rough estimate of 5 to 20 million tons of debris coming from Japan," University of Hawaii researcher Jan Hafner told Hawaii's ABC affiliate KITV.
Crew members from the Russian training ship the STS Pallada "spotted the debris 2,000 miles from Japan," last month after passing the Midway islands, the Mail wrote. "They saw some pieces of furniture, some appliances, anything that can float, and they picked up a fishing boat," said Hafner. The boat was 20-feet long, and was painted with the word "Fukushima." "That's actually our first confirmed report of tsunami debris," Hafner told KITV..."
NASA, Japan Release Improved Topographic Map of Earth
|1:55:31 AM, Monday, October 24, 2011|
"NASA and Japan released a significantly improved version of the most complete digital topographic map of Earth on Oct. 17, produced with detailed measurements from NASA's Terra spacecraft.
The map, known as a global digital elevation model, was created from images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument aboard Terra. So-called stereo-pair images are produced by merging two slightly offset two-dimensional images to create the three-dimensional effect of depth. The first version of the map was released by NASA and Japan's Ministry of Economy, Trade and Industry (METI) in June 2009.
"The ASTER global digital elevation model was already the most complete, consistent global topographic map in the world," said Woody Turner, ASTER program scientist at NASA Headquarters in Washington. "With these enhancements, its resolution is in many respects comparable to the U.S. data from NASA's Shuttle Radar Topography Mission, while covering more of the globe."
The improved version of the map adds 260,000 additional stereo-pair images to improve coverage. It features improved spatial resolution, increased horizontal and vertical accuracy, more realistic coverage over water bodies and the ability to identify lakes as small as 0.6 miles (1 kilometer) in diameter. The map is available online to users everywhere at no cost.
"This updated version of the ASTER global digital elevation model provides civilian users with the highest-resolution global topography data available," said Mike Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "These data can be used for a broad range of applications, from planning highways and protecting lands with cultural or environmental significance, to searching for natural resources."
The ASTER data cover 99 percent of Earth's landmass and span from 83 degrees north latitude to 83 degrees south. Each elevation measurement point in the data is 98 feet (30 meters) apart.
NASA and METI are jointly contributing the data for the ASTER topographic map to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This "system of systems" is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes..."
Planet-Sized Object as Cool as Earth Revealed in Record-Breaking Photo
|1:04:21 AM, Monday, October 24, 2011|
"The photo of a nearby star and its orbiting companion -- whose temperature is like a hot summer day in Arizona -- will be presented by Penn State Associate Professor of Astronomy and Astrophysics Kevin Luhman during the Signposts of Planets conference at NASA's Goddard Space Flight Center on Oct. 20, 2011.
A paper describing the discovery will be published in the Astrophysical Journal.
"This planet-like companion is the coldest object ever directly photographed outside our solar system," said Luhman, who led the discovery team. "Its mass is about the same as many of the known extra-solar planets -- about six to nine times the mass of Jupiter -- but in other ways it is more like a star. Essentially, what we have found is a very small star with an atmospheric temperature about cool as the Earth's."Luhman classifies this object as a "brown dwarf," an object that formed just like a star out of a massive cloud of dust and gas. But the mass that a brown dwarf accumulates is not enough to ignite thermonuclear reactions in its core, resulting in a failed star that is very cool. In the case of the new brown dwarf, the scientists have gauged the temperature of its surface to be between 80 and 160 degrees Fahrenheit -- possibly as cool as a human.
Ever since brown dwarfs first were discovered in 1995, astronomers have been trying to find new record holders for the coldest brown dwarfs because these objects are valuable as laboratories for studying the atmospheres of planets with Earth-like temperatures outside our solar system.
Astronomers have named the brown dwarf "WD 0806-661 B" because it is the orbiting companion of an object named "WD 0806-661" -- the "white dwarf" core of a star that was like the Sun until its outer layers were expelled into space during the final phase of its evolution. "The distance of this white dwarf from the Sun is 63 light years, which is very near our solar system compared with most stars in our galaxy," Luhman said.
"The distance of this white dwarf from its brown-dwarf companion is 2500 astronomical units (AU) -- about 2500 times the distance between the Earth and the Sun, so its orbit is very large as compared with the orbits of planets, which form within a disk of dust swirling close around a newborn star," said Adam Burgasser at the University of California, San Diego, a member of the discovery team. Because it has such a large orbit, the astronomers say this companion most probably was born in the same manner as binary stars, which are known to be separated as far apart as this pair, while remaining gravitationally bound to each other.
Luhman and his colleagues presented this new candidate for the coldest known brown dwarf in a paper published in spring 2011, and they now have confirmed its record-setting cool temperature in a new paper that will be published in the Astrophysical Journal.
To make their discovery, Luhman and his colleagues searched through infrared images of over six hundred stars near our solar system. They compared images of nearby stars taken a few years apart, searching for any faint points of light that showed the same motion across the sky as the targeted star. "Objects with cool temperatures like the Earth are brightest at infrared wavelengths," Luhman said. "We used NASA's Spitzer Space Telescope because it is the most sensitive infrared telescope available."
Luhman and his team discovered the brown dwarf WD 0806-661 B moving in tandem with the white dwarf WD 0806-661 in two Spitzer images taken in 2004 and 2009. The images, which together show the movement of the objects, are available online (http://science.psu.edu/alert/photos/research-photos/astro/Luhman-moving-labels.gif). "This animation is a fun illustration of our technique because it resembles the method used to discovery Pluto in our own solar system," Luhman said..."
Spiral Arms Hint at Presence of Planets: High Resolution Image of Young Star With Circumstellar Disks Verifies Predictions
|3:52:03 AM, Sunday, October 23, 2011|
"A new image of the disk of gas and dust around a sun-like star has spiral-arm-like structures. These features may provide clues to the presence of embedded but as-yet-unseen planets.
"Detailed computer simulations have shown us that the gravitational pull of a planet inside a circumstellar disk can perturb gas and dust, creating spiral arms. Now, for the first time, we're seeing these features," said Carol Grady, a National Science Foundation (NSF)-supported astronomer with Eureka Scientific, Inc.
The newly imaged disk surrounds SAO 206462, a star located about 456 light-years away in the constellation Lupus. Astronomers estimate that the system is only about 9 million years old. The gas-rich disk spans some 14 billion miles, which is more than twice the size of Pluto's orbit in our own solar system."The surprise," said Grady, "was that we caught a glimpse of this stage of planet formation. This is a relatively short-lived phase."
A near-infrared image from the National Astronomical Observatory of Japan shows a pair of spiral features arcing along the outer disk. Theoretical models show that a single embedded planet may produce a spiral arm on each side of a disk. The structures around SAO 206462 do not form a matched pair, suggesting the presence of two unseen worlds, one for each arm. However, the research team cautions that processes unrelated to planets may also give rise to these structures.
"What we're finding is that once these systems reach ages of a few million years, their disks begin to show a wealth of structure--rings, divots, gaps and now spiral features," said John Wisniewski, a collaborator at the University of Washington in Seattle. "Many of these structures could be caused by planets within the disks."
Grady's research is part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS), a five-year-long near-infrared study of young stars and their surrounding dust disks using the Subaru Telescope atop Mauna Kea in Hawaii. The international consortium of researchers now includes more than 100 scientists at 25 institutions.
"These arm-like structures have been predicted by models, but have never before been seen," said Maria Womack, program director for the division of Astronomical Sciences at NSF. "It is the first observation of spiral arms in a circumstellar disk, and an important test for models of planetary formation.""
Last Universal Common Ancestor More Complex Than Previously Thought
|3:42:30 AM, Sunday, October 23, 2011|
"Scientists call it LUCA, the Last Universal Common Ancestor, but they don't know much about this great-grandparent of all living things. Many believe LUCA was little more than a crude assemblage of molecular parts, a chemical soup out of which evolution gradually constructed more complex forms. Some scientists still debate whether it was even a cell.
New evidence suggests that LUCA was a sophisticated organism after all, with a complex structure recognizable as a cell, researchers report. Their study appears in the journal Biology Direct.
The study builds on several years of research into a once-overlooked feature of microbial cells, a region with a high concentration of polyphosphate, a type of energy currency in cells. Researchers report that this polyphosphate storage site actually represents the first known universal organelle, a structure once thought to be absent from bacteria and their distantly related microbial cousins, the archaea. This organelle, the evidence indicates, is present in the three domains of life: bacteria, archaea and eukaryotes (plants, animals, fungi, algae and everything else).
The existence of an organelle in bacteria goes against the traditional definition of these organisms, said University of Illinois crop sciences professor Manfredo Seufferheld, who led the study.
"It was a dogma of microbiology that organelles weren't present in bacteria," he said. But in 2003 in a paper in the Journal of Biological Chemistry, Seufferheld and colleagues showed that the polyphosphate storage structure in bacteria (they analyzed an agrobacterium) was physically, chemically and functionally the same as an organelle called an acidocalcisome (uh-SID-oh-KAL-sih-zohm) found in many single-celled eukaryotes.
Their findings, the authors wrote, "suggest that acidocalcisomes arose before the prokaryotic (bacterial) and eukaryotic lineages diverged." The new study suggests that the origins of the organelle are even more ancient.
The study tracks the evolutionary history of a protein enzyme (called a vacuolar proton pyrophosphatase, or V-H+PPase) that is common in the acidocalcisomes of eukaryotic and bacterial cells. (Archaea also contain the enzyme and a structure with the same physical and chemical properties as an acidocalcisome, the researchers report.)
By comparing the sequences of the V-H+PPase genes from hundreds of organisms representing the three domains of life, the team constructed a "family tree" that showed how different versions of the enzyme in different organisms were related. That tree was similar in broad detail to the universal tree of life created from an analysis of hundreds of genes. This indicates, the researchers said, that the V-H+PPase enzyme and the acidocalcisome it serves are very ancient, dating back to the LUCA, before the three main branches of the tree of life appeared.
"There are many possible scenarios that could explain this, but the best, the most parsimonious, the most likely would be that you had already the enzyme even before diversification started on Earth," said study co-author Gustavo Caetano-Anollés, a professor of crop sciences and an affiliate of the Institute for Genomic Biology at Illinois. "The protein was there to begin with and was then inherited into all emerging lineages."
"This is the only organelle to our knowledge now that is common to eukaryotes, that is common to bacteria and that is most likely common to archaea," Seufferheld said. "It is the only one that is universal."
The study lends support to a hypothesis that LUCA may have been more complex even than the simplest organisms alive today, said James Whitfield, a professor of entomology at Illinois and a co-author on the study..."
Animal Transplants Coming 'Soon'
|3:37:01 AM, Sunday, October 23, 2011|
"Are pigs about to migrate from the dinner table to the operating table?
Using animals as a source of organs for transplantation into humans was once one of medicine's next big things - a solution to transplant waiting lists.
However, there have been problems with rejection - and recently stem cells have been grabbing the spotlight.
But some researchers are now saying that transplants from animals "could soon become a reality", but not necessarily as originally expected.
There is still a pressing need for organs. In the UK there are 8,000 people on the waiting list - three die every day.
Several technologies are trying to meet the demand. In August, a patient from London was the first in the UK to have his heart replaced with a mechanical one while stem cells have been used for simple structures such as the windpipe.
However, using stem cells to build more complicated organs such as a heart is a long way off and mechanical body parts are used in the short term before an actual transplant.
Using animals as a source - known as "xenotransplantation" - is another potential solution.
Pigs have been used as a source of heart valves, which control the flow of blood around the heart. Here the pig cells are chemically stripped away and when the remaining structure is transplanted, human cells grow around it.
Stripping away the living material would not work for most transplants - nobody would want the heart that did not beat.
However, that living material has a big problem, namely rejection. The human immune system attacks the pig tissue, which it recognises as foreign.
Dr David Cooper from the University of Pittsburgh Medical Centre is one of a group of researchers arguing in the Lancet that the problems with organ rejection are being overcome.
Some pigs - GTKO pigs - have been genetically modified. They no longer produce a pig protein, galactosyltransferase, which the immune system would have attacked.
The authors say that this kind of rejection is "not the main cause of graft failure", however, "other issues have become more prominent"..."
Hawaii Astronomer Captures Image of Forming Planet
|8:27:36 PM, Thursday, October 20, 2011|
“Astronomers have captured the first direct image of a planet being born.
Adam Kraus, of the University of Hawaii's Institute for Astronomy, said the planet is being formed out of dust and gas circling a 2-milion-year-old star about 450 light years from Earth.
The planet itself, based on scientific models of how planets form, is estimated to have started taking shape about 50,000 to 100,000 years ago.
Called LkCa 15 b, it's the youngest planet ever observed. The previous record holder was about five times older.
Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea to find the planet.
"We're catching this object at the perfect time. We see this young star, it has a disc around it that planets are probably forming out of and we see something right in the middle of a gap in the disc," Kraus said in a telephone interview.
Kraus presented the discovery Wednesday at NASA's Goddard Space Flight Center in Maryland. Kraus and Ireland's research paper on the discovery is due to appear in The Astrophysical Journal.
Observing planets while they're forming can help scientists answer questions like whether planets form early in the life of a star or later, and whether they form relatively close to stars or farther away.
Planets can change orbits after forming, so it's difficult to answer such questions by studying older planets.
"These very basic questions of when and where are best answered when you can actually see the planet forming, as the process is happening right now," Kraus said.
Other planets may also be forming around the same star. Kraus said he'll continue to observe the star and hopefully will see other planets if there are in fact more.
Scientists hadn't been able to see such young planets before because the bright light of the stars they're orbiting outshines them.
Kraus and Ireland used two techniques to overcome this obstacle.
One method, which is also used by other astronomers, was to change the shape of their mirror to remove light distortions created by the Earth's atmosphere.
The other, unique method they used was to put masks over most of the telescope mirror. The combination of these two techniques allowed the astronomers to obtain high-resolution images that let them see the faint planet next to the bright star.
The astronomers found the planet while surveying 150 young dusty stars. This led to a more concentrated study of a dozen stars.
The star LkCa 15 — the planet is named after its star — was the team's second target. They immediately knew they were seeing something new, so they gathered more data on the star a year later.”
Qaddafi Is Killed as Libyan Forces Take Surt
|3:41:01 PM, Thursday, October 20, 2011|
"TRIPOLI, Libya — Col. Muammar el-Qaddafi, the former Libyan strongman who fled into hiding after an armed uprising toppled his regime two months ago, met a violent death Thursday in the hands of rebel fighters who stormed his final stronghold in his Mediterranean hometown Surt.
Al Jazeera television showed gruesome footage of what appeared to be Colonel Qaddafi, alive but bloody, being dragged around by armed men in Surt. The television also broadcast a separate clip of his half-naked body, with lifeless open eyes and an apparent gunshot wound to the side of the head, as jubilant fighters fired automatic weapons in the air.
Conflicting accounts quickly emerged about whether Colonel Qaddafi was executed by his captors, died from gunshot wounds sustained in a firefight, was mortally wounded in a NATO bomb blast or bled to death in an ambulance. But the images broadcast by Al Jazeera punctuated an emphatic and violent ending to his four decades as a ruthless and bombastic autocrat who had basked in his reputation as the self-styled king of kings of Africa.
“We have been waiting for this moment for a long time. Muammar Qaddafi has been killed,” Mahmoud Jibril, the prime minister of the Transitional National Council, the interim government, told a news conference in Tripoli. Mahmoud Shammam, the council’s chief spokesman, called it “the day of real liberation. We were serious about giving him a fair trial. It seems God has some other wish."
Libyan television also reported that one of Colonel Qaddafi’s feared fugitive sons, Muatassim, was killed in Surt, showing what it said was his lifeless bloodied body on a hospital gurney. There were also unconfirmed accounts that another feared son, Seif al-Islam, had been captured and possibly wounded.
In Washington, President Obama said in a televised statement that the death of Colonel Qaddafi signaled the start of a new chapter for Libya. “We can definitely say that the Qaddafi regime has come to an end,” he said. “The dark shadow of tyranny has been lifted and with this enormous promise the Libyan people now have a great responsibility to build an inclusive and tolerant and democratic Libya that stands as the ultimate rebuke to Qaddafi’s dictatorship.”
Libyans rejoiced as news of his death spread. Car horns blared and residents poured into the streets in giddy disbelief in Tripoli and in the eastern city of Benghazi, where the rebellion against Colonel Qaddafi began in February and escalated into the most violent of the Arab Spring uprisings.
“I can’t believe it’s over,” said Tahir Busrewil, a 26 year-old tourist industry worker in Tripoli who was imprisoned and tortured earlier this year, and had spent the past few weeks working with a militia to detain pro-Qaddafi loyalists. “Oh the relief! I never felt that happy about somebody being dead.” Walid Fakany, an anti-Qaddafi fighter from the Western mountain town of Rujban, who joined in the celebrations in Tripoli, said: “We can breathe, we can finally rest. Then we can move forward.”
Fighters from Misurata, the port city that suffered enormously at the hands of Colonel Qaddafi’s forces during the uprising, were in possession of Colonel Qaddafi’s body and took it to their hometown, where it was kept in a private house but moved a few hours later to an undisclosed location because hundreds of people had converged to see it, Misurata residents said.
Holly Picket, a freelance photojournalist working in Surt, reported in a twitter feed that she had seen Colonel Qaddafi’s body in an ambulance headed for Misurata, along with 10 fighters inside with him. It was unclear from her posting whether he was dead. “From the side door, I could see a bare chest with bullet wound and a bloody hand. He was wearing gold-colored pants,” she tweeted.
Within an hour of the news of Colonel Qaddafi’s death, the Arab twittersphere lit up with gleeful comments, many of them hinting at a similar fate awaiting other Arab dictators — most notably President Ali Abdullah Saleh of Yemen and President Bashar al-Assad of Syria. One of them read: “Ben Ali escaped, Mubarak is in jail, Qaddafi was killed. Which fate do you prefer, Ali Abdullah Saleh? You can consult with Bashar.” Another was more direct: “Bashar al-Assad, how do you feel today?” ..."
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