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Stories and comments across the archive that link to aas.org.
Stories · 7
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Venus May Have Been the First Habitable Planet In Our Solar System, Study Suggests (theguardian.com)
An anonymous reader quotes a report from The Guardian: Venus is often referred to as Earth's evil twin, but conditions on the planet were not always so hellish, according to research that suggests it may have been the first place in the solar system to have become habitable. The study, due to be presented this week at the at the American Astronomical Society Meeting in Pasadena, concludes that at a time when primitive bacteria were emerging on Earth, Venus may have had a balmy climate and vast oceans up to 2,000 meters (6,562 feet) deep. Michael Way, who led the work at the Nasa Goddard Institute for Space Studies in New York City, said: "If you lived three billion years ago at a low latitude and low elevation the surface temperatures would not have been that different from that of a place in the tropics on Earth," he said. Crucially, if the calculations are correct the oceans may have remained until 715m years ago -- a long enough period of climate stability for microbial life to have plausibly sprung up. "The oceans of ancient Venus would have had more constant temperatures, and if life begins in the oceans -- something which we are not certain of on Earth -- then this would be a good starting place," said Way. With an average surface temperature of 462C (864F), Venus is the hottest planet in the solar system today, thanks to its proximity to the sun and its impenetrable carbon dioxide atmosphere, 90 times denser than Earth's. At some point in the planet's history this led to a runaway greenhouse effect. Way and colleagues simulated the Venusian climate at various time points between 2.9 billion and 715 million years ago, employing similar models to those used to predict future climate change on Earth. The scientists fed some basic assumptions into the model, including the presence of water, the intensity of the sunlight and how fast Venus was rotating. In this virtual version, 2.9 billion years ago Venus had an average surface temperature of 11C (52F) and this only increased to an average of 15C (59F) by 715m years ago, as the sun became more powerful. Details of the study are also published in the journal Geophysical Research Letters. -
Faculty To Grad Students: Go Work 80-Hour Weeks!
New submitter Ian Paul Freeley writes "Controversy has erupted after a departmental email from faculty to astrophysics graduate students was leaked. Key tips for success in grad school include: 'However, if you informally canvass the faculty (those people for whose jobs you came here to train), most will tell you that they worked 80-100 hours/week in graduate school. No one told us to work those hours, but we enjoyed what we were doing enough to want to do so...If you find yourself thinking about astronomy and wanting to work on your research most of your waking hours, then academic research may in fact be the best career choice for you.' Reactions from astronomy blogs has ranged from disappointment to concern for the mental health of the students. It also seems that such a culture, coupled with the poor job prospects for academics, is continuing to drive talent away from the field. This has been recognized as a problem for over 15 years in the astronomy community, but little seems to have changed. Any tips for those of us looking to instigate culture change and promote healthy work-life balance?" -
Thunderstorms Proven To Create Antimatter
radioweather writes "Scientists using NASA's Fermi Gamma-ray Space Telescope have detected beams of antimatter from thunderstorms in the form of positrons hurled into space. Scientists think the antimatter particles were formed in a terrestrial gamma-ray flash, a brief burst produced inside thunderstorms and shown to be associated with lightning. 'These signals are the first direct evidence that thunderstorms make antimatter particle beams,' said Michael Briggs, a member of Fermi's Gamma-ray Burst Monitor team. He presented the findings at a news briefing at the American Astronomical Society meeting in Seattle." -
Dark Matter Revealed By Sagittarius Dwarf Galaxy
c0mpliant writes "A huge halo of dark matter that surrounds our galaxy has been revealed to astronomers at the University of California. The team, headed by Dr. David Law, examined the orbit of stars dragged out of the Sagittarius Dwarf Galaxy as it passed by the Milky Way. The team noticed that the pattern suggested the composition of dark matter around the Milky Way is not uniform, instead making what they refer to as a 'squashed beach ball' shape. This marks the first definitive measure of dark matter in our universe The announcement was made at the 215th American Astronomical Society Meeting, the largest astronomy meeting in history." -
Mars Flier Prototype
SEWilco writes "BBC News reports that a full-scale prototype of a Mars flier will be built. The ARES glider will unfold in midair for a mission which may cover 850 km (528 miles). I wonder if its huge wings would allow it to be tossed back in the air by a storm in that thin air, although probably not by "winds of a few m/sec"." -
Cluster Cracks Jupiter's Moons
YourHero writes: "Using the 256-cpu/500MHz Velocity I Cluster (64 Dell PowerEdge boxes installed Aug 1999) Cornell researchers have explained some of the wild moon orbits around Jupiter by running a 1-billion-year simulation. Abstract , abstract (presented at AAS/Division for Planetary Sciences), and news coverage [spaceflight now]. I saw no information on run time, but Aug 1999-present represents an upper limit somewhat short of 1 billion years." -
Cluster Cracks Jupiter's Moons
YourHero writes: "Using the 256-cpu/500MHz Velocity I Cluster (64 Dell PowerEdge boxes installed Aug 1999) Cornell researchers have explained some of the wild moon orbits around Jupiter by running a 1-billion-year simulation. Abstract , abstract (presented at AAS/Division for Planetary Sciences), and news coverage [spaceflight now]. I saw no information on run time, but Aug 1999-present represents an upper limit somewhat short of 1 billion years."