As astronomers develop better tools, they are able to find extrasolar planets of ever-smaller sizes and masses from giants like Jupiter down to exo-Neptunes and even, most recently, super-Earths. Soon they'll be finding many planets as small as our own. The ultimate goal is to examine these for signs of life.
Exoplanet researchers Sara Seager and Dimitar Sasselov, featured in the January 2009 Sky & Telescope, came by to talk about this exciting work with S&T editors Robert Naeye and Alan MacRobert.
Download the interview as a 23-MB MP3 file (25 minutes).