In Pictures: NASA - Kepler's most excellent space ...
An artist's conception of the tiny planet Kepler-37b, which is slightly larger than Earth's moon and orbits its host star every 13 days, in this image released by NASA, February 2013. It likely has a surface temperature of in excess of 400C (700F). Astronomers don't think the tiny planet has an atmosphere or could support life as we know it, but the moon-size world is almost certainly rocky in composition, NASA says.
In Pictures: NASA - Kepler's most excellent space discoveries