Astronomers find 3 smallest planets outside solar system

A team of astronomers led by scientists at the California Institute of Technology has discovered the three smallest confirmed planets ever detected outside our solar system. The three planets, which all orbit a single star, are smaller than Earth and appear to be rocky. Their existence suggests that the galaxy could be teeming with similarly rocky planets—and that there's a good chance that many are in the so-called habitable zone, where liquid water and possibly life could exist. Read more