Earth is perfectly suited for organic life. It stands to reason then that similar worlds orbiting distant stars might also be rich with life. But proving it will be a challenge. One of the better ways to discover extraterrestrial life will be to study the atmospheres of inhabited exoplanets, but Earth is fairly small for a planet and has a thin atmosphere compared to larger worlds. It will be much easier to study the atmospheres of gas planets, but could such worlds harbor life? A new paper in Universe argues it could.