2 'Nearby' Exoplanets Confirmed to Be Rocky — and May Be Habitable

Two Earth-size planets orbiting a nearby star are now confirmed to be rocky, strengthening the case that they might be habitable, a new study finds. The atmospheres of these worlds may range from vanishingly thin, like that of Mars, to hellishly dense, like Venus' air — and, possibly, comfortably in between, like Earth's, the researchers said. In May, astronomers reported the discovery of three Earth-size planets orbiting a dim, cold, red star named TRAPPIST-1.