|Puffy Planet Puzzle! |
Mystery Voles! 67 Dinosaurs Found!
Olmec Writing, General Relativity,
Lunar Meteor, Voices in Your Head?
|Puffy Planet Puzzles Professors!|
Washington DC September 14, 2006 - Using a network of small automated telescopes known as HAT, Smithsonian astronomers have discovered a planet unlike any other known world. This new planet, designated HAT-P-1, orbits one member of a pair of distant stars 450 light-years away in the constellation Lacerta.
"We could be looking at an entirely new class of planets," said Gaspar Bakos, a Hubble fellow at the Harvard-Smithsonian Center for Astrophysics (CfA). Bakos designed and built the HAT network and is lead author of a paper submitted to the Astrophysical Journal describing the discovery. That paper is available online at http://arxiv.org/abs/astro-ph/0609369
With a radius about 1.38 times Jupiter's, HAT-P-1 is the largest known planet. In spite of its huge size, its mass is only half that of Jupiter.
"This planet is about one-quarter the density of water," Bakos said. "In other words, it's lighter than a giant ball of cork! Just like Saturn, it would float in a bathtub if you could find a tub big enough to hold it, but it would float almost three times higher."
HAT-P-1 revolves around its host star every 4.5 days in an orbit one-twentieth of the distance from Earth to the Sun. Once each orbit, it passes in front of its parent star, causing the star to appear fainter by about 1.5 percent for more than two hours, after which the star returns to its previous brightness.
HAT-P-1's parent star is one member of a double-star system called ADS 16402 and is visible in binoculars. The two stars are separated by about 1500 times the Earth-Sun distance. The stars are similar to the Sun but slightly younger - about 3.6 billion years old compared to the Sun's age of 4.5 billion years.
Although stranger than any other extrasolar planet found so far, HAT-P-1 is not alone in its low-density status. The first planet ever found to transit its star, HD 209458b, also is puffed up about 20 percent larger than predicted by theory. HAT-P-1 is 24 percent larger than expected.
"Out of eleven known transiting planets, now not one but two are substantially bigger and lower in density than theory predicts," said co-author Robert Noyes (CfA). "We can't dismiss HD209458b as a fluke. This new discovery suggests something could be missing in our theories of how planets form."
Theorists had already considered a number of possibilities to explain the large size of HD 209458b, but so far without success. The only way to puff up these giant planets beyond the size calculated from planetary structure equations would be to supply additional heat to their interiors. Simple heating of the surface due to the host star's proximity would not work. (If it could, all close-in transiting giant planets should be expanded, not just two of them.)
One way to inject energy into the planet's center is by tipping it on its side, similar to Uranus in the solar system. A planet in that state orbiting close to its star would be subjected to tidal heating of the interior. But according to Smithsonian astronomer Matthew Holman (who was not a member of the discovery team), "the circumstances required to tip over a planet are so unusual that this would seem unlikely to explain both known examples of inflated worlds."
According to co-author Dimitar Sasselov (CfA), "Another explanation for HD 209458b's large size was tidal heating due to an eccentric orbit, but recent observations have pretty much ruled that out."
The scientists will continue observing HAT-P-1 to see if such an explanation could hold in this case, but "until we can find an explanation for both of these swollen planets, they remain a great mystery," Sasselov said.
The HAT network consists of six telescopes, four at the Smithsonian Astrophysical Observatory's Whipple Observatory in Arizona and two at its Submillimeter Array facility in Hawaii. These telescopes conduct robotic observations every clear night, each covering an area of the sky 300 times the size of the full moon with every exposure.
HAT searches for planets by watching for stars that dim slightly when an orbiting planet crosses directly in front of the star as viewed from Earth - a sort of mini-eclipse. Transits offer astronomers a unique opportunity to measure a planet's physical size from the amount of the dimming. Combined with the mass, which is determined by measuring the amount of the star's wobble as the planet orbits it, researchers then calculated a planet's density. Measurements of the wobble of HAT-P-1's parent star were led by co-author Debra Fischer of San Francisco State University.
Major funding for HATnet was provided by NASA. More information about HAT is available online at http://www.cfa.harvard.edu/~gbakos/HAT
Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.
Harvard-Smithsonian Center for Astrophysics - http://www.cfa.harvard.edu
September 14, 2006 - Purdue University research has shown that the vole, a mouselike rodent, is not only the fastest evolving mammal, but also harbors a number of puzzling genetic traits that challenge current scientific understanding.
"Nobody has posters of voles on their wall," said J. Andrew DeWoody, associate professor of genetics in the Department of Forestry and Natural Resources, whose study appears this month in the journal Genetica. "But when it comes down to it, voles deserve more attention."
Small rodents often confused for mice, except with shorter tails and beady eyes, voles live throughout the Northern Hemisphere and are often considered agricultural pests because they eat vegetation. Nevertheless, voles are an "evolutionary enigma" with many bizarre traits, DeWoody said. Understanding the basis for these traits could lead to better understanding of the same phenomena in human genetics and genetic disorders, and could have implications for gene therapy, he said.
The study focuses on 60 species within the vole genus Microtus, which has evolved in the last 500,000 to 2 million years. This means voles are evolving 60-100 times faster than the average vertebrate in terms of creating different species.
Within the genus (the level of taxonomic classification above species), the number of chromosomes in voles ranges from 17-64. DeWoody said that this is an unusual finding, since species within a single genus often have the same chromosome number.
"I have seen absolutely no evidence of mating between different species," Triant said. "We don't know how they do this, but scent and behavior probably play a role."
|67 Dinosaurs Found!|
BOZEMAN September 13, 2006 - One recent week in the Gobi Desert produced 67 dinosaur skeletons for a team of paleontologists from Montana and Mongolia who want to flesh out the developmental biology of dinosaurs.
Montana State University paleontologist Jack Horner said Wednesday that the same area yielded 30 skeletons last year, so researchers at MSU and Mongolia's Science and Technology University now have about 100 Psittacosaurus skeletons. The skeletons ranged in length from one to five feet and stood about two feet tall.
"That's what I was there for -- getting as many of those as we could possibly get," Horner said as he waited for the rest of the MSU team to return to Bozeman.
He was specifically looking for Psittacosaurus fossils because it was a very common dinosaur and would give him lots of specimens, Horner said. It would also keep away poachers and commercial fossil hunters who work in the area, but prefer rare fossils. Horner wants a large number of fossils so he can compare variations between skeletons and changes during growth.
The Psittacosaurus dinosaur, also known as a "parrot lizard," was a plant-eater that lived about 120 million years ago in the Early Cretaceous Period, Horner said. It was an ancestor of horned dinosaurs like the triceratops.
"The reason I went after Psittacosaurus was because I figured I could get more of those dinosaurs in the shortest period of time than any other dinosaur," Horner added.
Horner and his group left near the end of August for Mongolia. Joined there by Bolortsetseg Minjin and her team of Mongolian students, the paleontologists drove two days out of Ulan Bator. There, in a few square miles of badlands, they worked from sun-up to sundown and collected dozens of fossils.
This summer's fossils have all been excavated and are now at the Mongolian university, Horner said. Jamie Cornish, marketing director at MSU's Museum of the Rockies, said the bones belong to Mongolia, but Horner may obtain casts of them. Horner added that he will be able to study some of the fossils in Montana, but they will be returned to Mongolia.
"We can bring specimens here for a little while, but the Museum of the Rockies is not the place for bones from other countries," Horner said. "We have enough stuff."
|US Prisons Unprepared for Flu Pandemic!|
|Saint Louis University News Release |
ST. LOUIS September 15, 2006 – As the fear of an impending avian flu pandemic is compelling hospitals, businesses and cities to develop preparedness plans, one of the most potentially dangerous breeding grounds of disease is woefully ill-prepared for a crisis, according to a new study being presented today by researchers at Saint Louis University.
"There’s a real failure to recognize how important the health status of inmates is to the public health of all of us," says Rachel Schwartz, Ph.D., a researcher at the Institute for Biosecurity at Saint Louis University School of Public Health. "Nearly 85 percent of those in jails and prisons will be released within a year. So even if we as a society don't think protecting them from disease is a priority, prisoners released into the general population pose a real threat to society."
The research is being presented today at the Correctional Medicine Institute’s 2006 Conference in Baltimore. There are more than two million prisoners in the United States, making up what Schwartz calls "a highly vulnerable population."
"There’s a much higher level of disease among prisoners – people with HIV, drug-resistant tuberculosis, hepatitis C and other diseases," she says. She adds that 80 percent of inmates come to prison with some sort of illness.
"And once they’re incarcerated, they’re more likely to get other diseases. It makes correctional facilities into ticking time bombs. Many people crowded together, often suffering from diseases that weaken their immune systems, form a potential breeding ground and reservoir for diseases."
Schwartz and fellow researchers studied research and protocols from the Centers for Disease Control, the World Health Organization and other governments to identify what plans were in place for prisons should an infectious disease break out. Many of the correctional facilities that Schwartz and colleagues studied have acknowledged they don’t have an adequate plan to deal with a pandemic or similar health crisis. Schwartz says there’s reluctance among government leaders to provide prisoners with medical care, such as flu vaccines.
"The thinking is that there won’t be enough for the general public, and that they should get the shots first," she says. "We tend to think of all inmates as being violent offenders, but the average length of incarceration is only 48 hours. Many are not convicted criminals, but rather people merely accused of crimes and awaiting trial. "We know that illness among prisoners will eventually spread and cause illness in society, so we must address this now."
The solution, says Schwartz, is to spend more energy and money on preparedness. She and fellow researchers developed a plan to educate the judicial and prison systems on ways to prevent the spread of disease, from meticulous hand-washing to appropriate use of quarantine and isolation in prison and jail settings.
The pandemic plans are designed to provide useful information for many kinds of crisis situations, Schwartz says.
"Ideally, they will help authorities prepare and respond to anything from a bird flu breakout to a biological attack. The information is also critical for existing illnesses within prisons, like HIV, not just emerging infections."
Saint Louis University - http://www.slu.edu
|Olmec Writing Dated to 900 BC|
PROVIDENCE RI September 14, 2006 - New research published this week in Science details the discovery of a stone (serpentine) block in Veracruz, Mexico, containing a previously unknown system of writing, thought to be the earliest in the New World.
An international team of archaeologists, including Brown University's Stephen D. Houston, de-termined that the slab – named the "Cascajal block" – dates to the early first millennium BC and has features that indicate it comes from the Olmec civilization of Mesoamerica. They say the block and its ancient script "link the Olmec civilization to literacy, document an unsuspected writing system, and reveal a new complexity to this civilization."
"It's a tantalizing discovery. I think it could be the beginning of a new era of focus on Olmec civilization," said Houston, an expert on ancient writing systems and corresponding author of the article. "It's telling us that these records probably exist and that many remain to be found. If we can decode their content, these earliest voices of Mesoamerican civilization will speak to us today."
|General Relativity Passes Pulsar Test!|
15 September 2006 - Astronomers have used a pair of pulsars orbiting each other, found with CSIRO’s Parkes telescope in 2003, to show that Einstein’s theory of general relativity is correct to within 0.05% – the most stringent limit to date.
They also hope to be able to use the two pulsars to determine the exact nature of the matter that pulsars and other neutron stars are made of. Their results are to be published in the journal Science, and made available online in Science Express Science Express on 14 September 2006.
An international research team led by Professor Michael Kramer of the University of Manchester's Jodrell Bank Observatory, UK, has been observing the double-pulsar system since 2003 with three of the world’s largest radio telescopes: CSIRO’s Parkes radio telescope in NSW, Australia; the Lovell Telescope near Manchester, UK; and the Robert C. Byrd Green Bank Telescope in West Virginia, USA.
The double-pulsar system, whose pulsars are called PSR J0737-3039A and B, is the only known system of radio pulsars orbiting each other. It lies 2000 light-years away in the direction of the constellation Puppis.
The system consists of two massive, highly compact neutron stars, each weighing more than our own Sun but only about 20 km across, orbiting each other every 2.4 hours at speeds of a million kilometres per hour.
Separated by a distance of just a million kilometres, both neutron stars emit lighthouse-like beams of radio waves that are seen as radio ’pulses‘ every time the beams sweep past Earth.
By precisely measuring the variations in pulse arrival times, the researchers found the movement of the stars to exactly follow Einstein's predictions.
"This is the most stringent test ever made of GR in the presence of very strong gravitational fields—only black holes show stronger gravitational effects, but they are obviously much more difficult to observe," Professor Kramer says.
Co-author Ingrid Stairs, an assistant professor at the University of British Columbia in Vancouver, Canada, says it is possible to measure the pulsars’ distances from their common centre of mass.
"The heavier pulsar is closer to the centre of mass, or pivot point, than the lighter one and this allows us to calculate the ratio of the two masses," she says.
This mass ratio is independent of the theory of gravity, and so tightens the constraints on general relativity and any alternative gravitational theories.
Other relativistic effects predicted by Einstein can be observed: the fabric of space-time around pulsar B is curved, and the other pulsar’s "clock" runs slower when it is deeper in the gravitational field of its massive companion. Each of these effects provides an independent test of general relativity.
The distance between the pulsars is shrinking by 7 mm a day. Einstein's theory predicts that the double pulsar system should be emitting gravitational waves – ripples in space-time that spread out across the Universe at the speed of light.
"These waves have yet to be directly detected," says team member Prof. Dick Manchester of CSIRO’s Australia Telescope National Facility ATNF).
"But, as a result, the double pulsar system should lose energy causing the two neutron stars to spiral in towards each other by precisely the amount that we have observed – thus our observations give an indirect proof of the existence of gravitational waves."
|New Lunar Meteorite Found in Antarctica|
September 14, 2006 - Although last year's inclement weather resulted in fewer Antarctic meteorite recoveries than usual, scientists have recently discovered that one of the specimens is a rare breed -- a type of lunar meteorite seen only once before.
The new specimen was found by a field party from the U.S. Antarctic Search for Meteorites program (ANSMET) headquartered at Case Western Reserve University. The meteorite was discovered on Dec. 11, 2005, on an icefield in the Miller Range of the Transantarctic Mountains, roughly 750 km from the South Pole.
This 142.2 g black rock, slightly larger than a golfball and officially designated MIL 05035, was one of 238 meteorites collected by ANSMET during the 2005-2006 austral summer. Heavy snows limited search efforts during much of the remainder of the six-week field season, making this meteorite, discovered just 600 m from camp, a particularly welcome find.
Scientists involved in classification of Antarctic finds at NASA's Johnson Space Center and the Smithsonian Institution's National Museum of Natural History said the mineralogy and texture of the meteorite are unusual. The new specimen is a very coarse-grained gabbro, similar in bulk composition to the basaltic lavas that fill the lunar maria, but its very large crystals suggest slow cooling deep within the Moon's crust.
In addition, the plagioclase feldspar has been completely converted to glass, or maskelynite, by extreme shock (presumably impact events). The new specimen most closely resembles another Antarctic meteorite, Asuka 881757, one of the oldest known lunar basalt samples.
Like the other lunar meteorites, MIL 05035 is a piece of the Moon that can be studied in detail in the laboratory, providing new specimens from a part of the lunar surface not sampled by the US Apollo program. Many researchers believe that Apollo visited some of the most unusual and geochemically anomalous regions of the Moon, and lunar meteorites, knocked off the surface of the Moon by random impacts, give us samples that are more representative of the Moon as a whole.
The highly-shocked nature of MIL 05035 suggests an old age and may provide new constraints on the early intense bombardment of the Earth-Moon system, improving our understanding of the history of the Earth's nearest neighbor and aiding NASA's efforts toward a return to the Moon.
Following the existing protocols of the U.S. Antarctic meteorite program, scientists from around the world will be invited to request samples of the new specimen for their own detailed research. Details concerning initial characterization of the specimen and sample availability are available through the Antarctic Meteorite Newsletter, available on the Web at http://curator.jsc.nasa.gov/curator/antmet/amn/amn.htm and mailed to researchers worldwide.
Discovery of this meteorite occurred during the fourth full field season of a cooperative effort by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA) to enhance recovery of rare meteorite types in Antarctica, in the hopes new Martian samples would be found.
Case Western Reserve University - http://www.case.edu
|Voices in Your Head?|
September 13, 2006 - Psychologists have launched a study to find out why some people who hear voices in their head consider it a positive experience while others find it distressing.
The University of Manchester investigation – announced on World Hearing Voices Day (Thursday, 14th September) – comes after Dutch researchers found that many healthy members of the population there regularly hear voices.
Although hearing voices has traditionally been viewed as 'abnormal' and a symptom of mental illness, the Dutch findings suggest it is more widespread than previously thought, estimating that about 4% of the population could be affected.
Researcher Aylish Campbell said: "We know that many members of the general population hear voices but have never felt the need to access mental health services; some experts even claim that more people hear voices and don't seek psychiatric help than those who do.
"In fact, many of those affected describe their voices as being a positive influence in their lives, comforting or inspiring them as they go about their daily business. We're now keen to investigate why some people respond in this way while others are distressed and seek outside help."
Although the voices heard by psychiatric patients and members of the general population seem to be of the same volume and frequency, the former group tend to interpret the voices as more distressing and negative.
The team believes that external factors such as a person's life experiences and beliefs may be the key to these differences: for example, the presence of childhood trauma or negative beliefs about themselves could have an affect.
"If a person is struggling to overcome a trauma or views themselves as worthless or vulnerable, or other people as aggressive, they may be more likely to interpret their voices as harmful, hostile or powerful," said Aylish.
"Conversely, a person who has had more positive life experiences and formed more healthy beliefs about themselves and other people might develop a more positive view of their voices.