Planets are generally divided into two main types: large, low-density gas giants, and smaller, rocky terrestrials. As of February 2009, there are 342 known extrasolar planets, ranging from the size of gas giants to that of terrestrial planets
Planets are generally divided into two main types: large, low-density gas giants, and smaller, rocky terrestrials. As of February 2009, there are 342 known extrasolar planets, ranging from the size of gas giants to that of terrestrial planets