If, as we have often speculated in these pages, there is a brown dwarf closer to us than the Centauri stars, it may well be the WISE mission that finds it. The Wide-field Infrared Survey Explorer is a 40 cm telescope cooled below 17 K (-430 Fahrenheit) that will image the entire sky in four infrared wavelengths. If we're looking for nearby brown dwarfs, an all-sky survey like this is the way to go, because such stars should be distributed uniformly in the space around us. According to information Amanda Mainzer (JPL) presented yesterday at the American Astronomical Society meeting in Long Beach (CA), brown dwarfs are now thought to make up two-thirds of the stars in our stellar neighborhood, most of them as yet undetected. One of them might well be closer than the 4.3 light years that separate us from Alpha Centauri. And WISE should be up to the challenge of finding it, being able to detect cool brown dwarfs (down to 200 K) at Centauri distance and objects down to Jupiter-mass if...

The American Astronomical Society meeting now in session in Long Beach (CA) is already making news. Led by Michael Jura (UCLA), a team of scientists has used Spitzer Space Telescope data to study six white dwarf stars that are surrounded with the remains of asteroids. The assumption here is that these materials are a likely indication of planetary formation in these systems, for they're the same materials that go into making up the Earth and other rocky worlds in our own Solar System. "If you ground up our asteroids and rocky planets, you would get the same type of dust we are seeing in these star systems," says Jura, who presented the results at the meeting this morning. "This tells us that the stars have asteroids like ours -- and therefore could also have rocky planets." When a star like our Sun reaches the end of its life and becomes a red giant, it consumes any inner planets and perturbs the orbits of the surviving planets and asteroids. A white dwarf is the end result of this...