The remnant of supernova 1987a lights up.
This supernova is the only naked eye supernova since the invention of the telescope, and has been tracked by Hubble for two decades.
An evening pause: a beautiful simulation of galaxy collision. Hat tip: Sky and Telescope.
A new supernova has erupted in the nearby galaxy M51, 23 million light years away.
The James Webb Space Telescope: The disaster that destroyed NASA’s astrophysics program.
Planetary scientists push for Enceladus mission to search for alien life.
Budget deficits signal a decline in spending for astronomy telescopes, both on the ground and in space, for the next decade.
A photo atlas of galactic “train wrecks.”
More on the new Kepler results: Lots of multiple planet systems.
New results from Kepler.
A paper published today on the Los Alamos astro-ph preprint website has taken a close look at identifying the best nearby asteroids ideal for mounting a manned mission. The conclusion: our survey of such asteroids is very incomplete (only 65 known), and due to their location in Earthlike orbits they are very difficult to study.
Ultra-low delta-v NEOs are not readily found. Their closely Earth-like orbits mean that most of the time they are in the daytime sky, as seen from the Earth, and so are effectively undetectable. As they approach within <1AU of the Earth they start to lie near quadrature, and so come into the dawn or dusk sky on Earth. The strong scattered sunlight background makes optical surveys toward the dawn or dusk much less sensitive and, in practice, surveys do not look in these directions, preferring to observe where the sky is dark, within 45 degrees, and at most 60 degrees, of the anti-Sun, opposition, direction. As a consequence the lowest delta-v NEOs are undercounted by current surveys, and the factor by which they are undercounted is not yet known.
The paper proposes building a dedicated unmanned infrared mission and placing it in a Venus-like orbit where it would be better placed to see these difficult but important objects.
New data provides further confirmation of the existence of dark energy.
Astronomers, Kepler, and SETI@home team up to find exoplanets.
Is the extrasolar planet Gliese 581d habitable? Maybe.
Private citizen has just donated $25 million for the construction of the Giant Magellan Telescope.
This is how it used to be done all the time: All the early giant telescopes built in the United States before World War II were financed by individuals or private foundations, with no or little government investment.
In mid-April the Crab Nebula erupted for six days, repeatedly emitting the most powerful flares ever recorded from the supernova remnant.
Scientists think the flares occur as the intense magnetic field near the pulsar undergoes sudden restructuring. Such changes can accelerate particles like electrons to velocities near the speed of light. As these high-speed electrons interact with the magnetic field, they emit gamma rays.
To account for the observed emission, scientists say the electrons must have energies 100 times greater than can be achieved in any particle accelerator on Earth. This makes them the highest-energy electrons known to be associated with any galactic source. Based on the rise and fall of gamma rays during the April outbursts, scientists estimate that the size of the emitting region must be comparable in size to the solar system.
Dawn captures its first image of the asteroid Vesta as it closes in on a rendezvous set for July 16.
Pop! Analysis of the images that Stardust took of Comet Tempel 1 strongly suggest that when Deep Impact hit the comet’s surface it broke open several underground cavities that then burst like balloons.
Every year, as part of its educational and research mission, the Space Telescope and Science Institute in Baltimore, Maryland holds a science symposium that focuses one of the big questions of astronomy, inviting over a hundred scientists to come and give their individual perspectives on the state of the field.
This year’s symposium ended yesterday, and the subject was the mysteries of dark matter. Though I wasn’t able to attend the symposium itself, they held a workshop for journalists yesterday, which I did attend. (You can watch the webcast here.)
So, what is dark matter?
First of all, it isn’t dark energy. Dark energy is that mysterious unknown phenomenon that is causing — on vast scales of many billions of light years — the expansion of the universe to accelerate rather than decelerate. It has nothing to do with the question of dark matter.
Second, no one knows. All that scientists do know is that objects in the outer regions of galaxies as well as the galaxies themselves don’t move at the speeds and directions expected if their known mass and gravity were the only forces influencing them. In order to successfully plot their orbits and motions, astronomers have to add a gigantic halo of extra mass, which they have dubbed “dark matter” because it is unseen, undetected, and completely invisible.
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Scientists have found evidence that a subsurface ocean of water and ammonia exists within Saturn’s moon Titan.
Dark matter: light or heavy?
Later today I will be attending press conference at a symposium on dark matter that is being held this week at the Space Telescope Science Institute in Baltimore. I will post more on this subject then.
Why is the Meathook galaxy lopsided?
More information on the asteroid “flyby” of Earth this coming November 8.
“On November 8, asteroid 2005 YU55 will fly past Earth and at its closest approach point will be about 325,000 kilometers [201,700 miles] away,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. “This asteroid is about 400 meters [1,300 feet] wide – the largest space rock we have identified that will come this close until 2028.”
Space telescopes Hubble and Swift have proven that the debris that suddenly surrounded asteroid Scheila last year was caused by a collision.
