Astronomers Say Super-Earths Are Actually Mini-Neptunes

Among the 860 exoplanets documented so far, a good portion of them are so-called super-Earths — planets that feature a mass greater than Earth's, but lower than our solar system's smaller gas giants, namely Uranus and Neptune (both of which are about 15 Earth masses). And as the name implies, some of these… » 2/05/13 8:00am 2/05/13 8:00am