I know this is a bit old, but it's still cool: Astronomers bagged the lowest mass planet yet; it has just under twice the mass of Earth! It's very close to its star and too hot for life as we know it, but that lower limit keeps creeping down. And with Kepler now patrolling a patch of the sky, how long will it be before Terra Nova is found?
New lowest mass planet found
May 1, 2009