Here's something to consider re the recent Pluto news: The Hubble maps of the tiny world that were released yesterday show a resolution of roughly 300 miles per pixel. When New Horizons flies by Pluto/Charon in 2015, it will send images with a resolution of 300 feet per pixel. And we've been reminded once again that every time we look deeper into something hitherto unexplored, we're likely to be surprised. The surprise in this case was the significant reddening of the dwarf planet and the time frame in which it occurred, a mere two years. I thought the liveliest part of the teleconference on Pluto yesterday was Marc Buie's response to what had appeared in his datasets. Buie (Southwest Research Institute) was looking at imagery collected by the Hubble Space Telescope from 2002 to 2003 and comparing it with the results of earlier ground-based observations, as well as with Hubble pictures taken in 1994. The dramatic reddening seems to have occurred between 2000 and 2002, even as the...

Collisions between asteroids should be highly energetic affairs, with an average impact speed of close to 5 kilometers per second. We may be looking at the debris of a head-on collision between two asteroids in imagery provided by the Hubble Space Telescope. The object in question, originally thought to have been a comet, is P/2010 A2, discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) sky survey on January 6 of this year. The follow-up Hubble imagery dates from late January, and shows an unusual filamentary pattern near the nucleus. Image: HST picture of the comet-like object called P/2010 A2. The object appears so unusual in ground-based telescopic images that discretionary time on Hubble was used to take a close-up look. This picture, from the January 29 observation, shows a bizarre X-pattern of filamentary structures near the point-like nucleus of the object and trailing streamers of dust. The inset picture shows a complex structure that suggests the object is not a...

Adding punch to the National Research Council's recent report on detecting near-Earth objects is the first asteroid detection by WISE, the Wide-Field Infrared Survey Explorer. We've focused in these pages primarily on WISE's ability to spot nearby brown dwarfs, but the mission is going to map the entire sky in infrared light and its discoveries should range from the inner system to distant galaxies. As an asteroid hunter, WISE is demonstrating it will be second to none, quickly spotting the object now designated 2010 AB78, a finding soon confirmed at visible light wavelengths at the University of Hawaii's 2.2-meter instrument at Mauna Kea. At 158 million kilometers from Earth, the asteroid, some 1 kilometer in diameter, poses no impact threat for the foreseeable future, but all asteroid and comet detections from WISE move nonetheless to the Minor Planet Center in Cambridge (MA) and follow-up observations then establish firm orbital data for newly discovered objects. The thinking is...

What goes on under the clouds of Neptune and Uranus? A new paper reinforces the possibility that there are oceans of liquid diamond in such places, diamond seas with solid diamond icebergs. It's a notion with a pedigree. I'm looking, for example, at a paper by David Stevenson (Caltech) from the Journal de Physique from November of 1984, where I find this: There is clear evidence that many hydrocarbons decompose (or collapse) upon shock compression, probably into graphite and hydrogen. It is very important to establish the range of temperature and C:H ratios for which this decomposition can occur. It is equally important to establish whether an actual phase separation occurs (implying possible formation of a diamond or liquid metallic (?) carbon layer in Uranus and Neptune) or whether a collapsed but intimately mixed C-H structure results. Stevenson's work built on that of Marvin Ross, who suggested the possibility of diamonds in this environment in 1981. Researchers at the University...