NASA scientists have discovered the smallest planet yet found going around a star similar to our Sun. It is only one third the size of Earth, slightly larger than our Moon. Located 210 light years away in the constellation Lyra, this system has two more planets.

The moon-size planet called Kepler-37b, and its two companion planets were found by scientists with NASA's Kepler mission, which is designed to find Earth-sized planets in or near the "habitable zone," the region in a planetary system where liquid water might exist on the surface of an orbiting planet. However, while the star in Kepler-37 may be similar to our sun, the system appears quite unlike the solar system in which we live.