NASA scientists today announced the discovery of two Earth-sized planets.
The planets were discovered by the Kepler space telescope team.
The two planets are believed to be too close to their sun and thus too hot to be habitable with temperatures ranging from 800 to 1,400 degrees.
Scientists speculate that one of the planets called Kepler 20F might have had liquid water at one time in its history and
could have been habitable.
The Kepler science team says this is the first time humanity has been able to detect planets of Earth size in the universe.