The Milky Way appears to be peppered with so-called Super-Earths — distant exoplanets that are between two to 10 Earth masses. Many of them have even been detected within habitable zones. But a new study shows it doesn't matter. They're all just dead worlds.
Super-Earths — many of which are Mini-Neptunes — can be terrestrial planets like Earth, or gaseous blobs like Uranus and Neptune. Astronomers have catalogued nearly 400 of these exoplanets (many of which were identified in a recent Kepler study).