Extrasolar meteors hint at distant planet formation

Candian astronomers say that detecting microscopic meteors from other solar systems could provide clues about the formation of planets like Earth. Dust streams from our sun’s stellar neighbours consist of tiny grains of pulverized rock ejected from a disk of dust and debris that commonly surrounds young stars, says Joseph Weingartner, a post-doctoral fellow at the University of Toronto’s Canadian Institute for Theoretical Astrophysics. According to Professor Norman Murray, associate director of CITA and co-author of the study, “if we can detect these grains and trace them back to the star system that they came from, we’d have very good evidence of planet formation going on in that system.” Weingartner presented the study Jan. 6 at the American Astronomical Society meeting in Seattle, Wash.

Distant Ring of Stars Found Around the Milky Way

A previously unseen band of stars beyond the edge of the Milky Way galaxy has been discovered by a team of scientists from Rensselaer Polytechnic Institute, Fermi National Accelerator Laboratory, and the Sloan Digital Sky Survey (SDSS). The discovery could help to explain how the galaxy was assembled 10 billion years ago.

Milky Way monster stars in cosmic reality show

The longest X-ray look yet at the supermassive black hole at the Milky Way’s center has given astronomers unprecedented access to its life and times. The new data from NASA’s Chandra X-ray Observatory revealed that our galaxy’s central black hole is a frequent bad actor, prone to numerous outbursts and occasional large explosions.

Planet-Hunting Machine is Getting Even Better

The world’s best planet-hunting machine, the Keck High Resolution Echelle Spectrometer, will be getting even better this year with an advanced imaging array that will improve efforts to detect extra-solar planets, examine distant quasars, measure extragalactic stars and do other research requiring very precise wavelength measurements of thousands of color channels with one exposure. HIRES, a visible-wavelength spectrometer responsible for 20 percent of the science on the Keck I telescope, will be getting an advanced new detector that will increase photon detection rates at ultraviolet wavelengths by a factor of 8 (at 3200 ?), expand single-exposure wavelength coverage, provide finer sampling of spectral features, and allow faster readout rates to provide higher-quality science in less time.

Scientists catch their first elusive ‘dark’ gamma-ray burst

Scientists racing the clock have snapped a photo of a gamma-ray burst event one minute after the explosion, capturing for the first time a particularly fast-fading type of “dark” burst, which comprises about half of all gamma-ray bursts. A gamma-ray burst announces the birth of a new black hole; it is the most powerful type of explosion known, second only to the Big Bang in total energy release. This latest finding may double the number of gamma-ray bursts available for study and rattle a few theories as well, said scientists from the Massachusetts Institute of Technology, based on an X-ray image taken by the MIT-built High Energy Transient Explorer (HETE) satellite, the first satellite dedicated to spotting gamma-ray bursts.

Pair says ‘dark energy’ dominates the universe

A Dartmouth researcher is building a case for a “dark energy”-dominated universe. Dark energy, the mysterious energy with unusual anti-gravitational properties, has been the subject of great debate among cosmologists. Brian Chaboyer, Assistant Professor of Physics and Astronomy at Dartmouth, with his collaborator Lawrence Krauss, Professor of Physics and Astronomy at Case Western Reserve University, have reported their finding in the January 3, 2003, issue of Science. Combining their calculations of the ages of the oldest stars with measurements of the expansion rate and geometry of the universe lead them to conclude that dark energy dominates the energy density of the universe.

Evolution of Galaxy-Spanning Magnetic Fields Explained

Researchers have uncovered how giant magnetic fields up to a billion, billion miles across, such as the one that envelopes our galaxy, are able to take shape despite a mystery that suggested they should collapse almost before they?d begun to form. Astrophysicists have long believed that as these large magnetic fields grow, opposing small-scale fields should grow more quickly, thwarting the evolution of any giant magnetic field. The team discovered instead that the simple motion of gas can fight against those small-scale fields long enough for the large fields to form.

GPS technology to help the blind

A new navigation tool to help blind people find their way around city streets is soon to be tested under a European Space Agency project. The hand-held device incorporates ESA’s new satellite navigation technologies into the personal navigator for blind people. At present, satellite navigation based on GPS and without the use of inertial systems, is not accurate enough to guide pedestrians, especially around cities. When few GPS satellites are in view because of tall buildings, positioning accuracy can be little better than 30 to 40 m. ESA’s EGNOS system, however, improves the accuracy of GPS positions to a few metres, making it sensitive enough to locate obstacles in the street.

Surprises from Past Could Spell Longer Droughts, Rising Sea Levels

Abrupt climate changes could lead to decade-long droughts and massive sea-level rise, according to a University of Arizona geoscientist who studies the climate of the distant past. Factors that influence the climate system, such as natural changes in the Earth’s orbit or rising carbon dioxide emissions from cars and power plants, can result in dramatic climate shifts, says Jonathan Overpeck, a professor of geosciences and director of the UA Institute for the Study of Planet Earth. Scientists studying natural climate records, such as the variations in tree rings and gas bubbles trapped in the polar ice caps, find ample evidence of these types of rapid changes in the past — sometimes occurring in a decade or less.

Methane Clouds Discovered at the South Pole of Titan

Teams of astronomers at the California Institute of Technology and the University of California at Berkeley have discovered methane clouds near the south pole of Titan. Titan is Saturn’s largest moon, larger than the planet Mercury, and is the only moon in our solar system with a thick atmosphere. Like Earth’s atmosphere, the atmosphere on Titan is mostly nitrogen. Unlike Earth, Titan is inhospitable to life due to the lack of atmospheric oxygen and its extremely cold surface temperatures (-183 C; -297 F). Along with nitrogen, Titan’s atmosphere contains a significant amount of methane. Earlier spectroscopic observations had hinted at the existence of clouds on Titan, but gave no clue as to their location.

Microorganisms isolated in space

Indian and British researchers say they have successfully isolated microorganisms living in the upper atmosphere, as high as 40 km up. Whether the organisms originate on Earth or are “seeding” the planet from passing comets is the subject of some debate. “Contamination is always a possibility in such studies but the ‘internal logic’ of the findings points strongly to the organisms being isolated in space, at a height of 41km,” said one of the lead researchers. “Of course the results would have been more readily accepted and lauded by critics had we isolated novel organisms, or ones with NASA written on them! “

NASA observatory reveals pileup on cosmic speedway

Lobes of unexpectedly hot gas speeding away from a black hole in our galaxy have been discovered with NASA ‘s Chandra X-ray Observatory. The high temperature and the distance of the lobes from the black hole indicate that violent collisions are occurring between clumps of gas expelled from the vicinity of the black hole. A key finding was evidence indicating rapidly moving hot iron atoms. “Just like a super-highway, it’s a dangerous world out there,” said Simone Migliari on the University of Amsterdam, lead author on a paper from a September 6, 2002 issue of Science magazine. “Blobs of gas are getting rear-ended at speeds in excess of a hundred million miles per hours!”