The Habitable Exoplanets Catalog is a database of the planets outside our solar system which are considered the most suitable for life according to certain steps and metrics. So far 16 have been identified as possible candidates. This Guardian article is a good introduction. You can also just dive into the catalogue, which ranks planets on two main scales, similarity to Earth and surface habitability (note that all images are computer renderings). The catalog is a project of the Planetary Habitability Laboratory at University of Puerto Rico in Arecibo (home to the world's largest radiotelescope).
posted by Kattullus on Dec 5, 2011 - 42 comments

Two Moons Passing in the Night. Mars rover Spirit took these sequential photos of Martian moons Phobos and Deimos passing overhead in the night sky. Those rovers are still going strong!
posted by brownpau on Sep 10, 2005 - 17 comments

Swan song for a great explorer. Tomorow, the Galileo explorer will make a flyby of Jovian moon Amalthea ending pehaps the geatest unmanned mission in NASA history. Galileo telemetry may not survive the flyby having already receieved much more radiation than it was designed for. Even if it does survive, this will be its final orbit scheduled to crash into Jupiter in September of next year. In spite of antenna difficulties, the spacecraft returned many beautiful images of Jupiter's moons, along with coverage of the Shoemaker-Levy collision and the first atmospheric probe to decend into Jupiter's weather.
posted by KirkJobSluder on Nov 3, 2002 - 9 comments

Interesting hypothesis that Europa's seas are swimming with bacteria. Preliminary results show that all three species, the ordinary gut bacteria Escherichia coli, and extremophiles Deinococcus radiodurans and Sulfolobus shibatae, are just as good at explaining Europa's IR spectrum as the [magnesium sulphate] salts.
posted by skallas on Dec 13, 2001 - 10 comments

Once in a blue moon. Not only will the full moon on Halloween be the first in 40(i think) and the last for another 19 years, it is also a 'blue moon' which means that the moon is full twice in the same month. Notwithstanding any MeFi visitors from Detroit, are you feeling strange yet?
posted by donkeysuck on Oct 30, 2001 - 25 comments