sentences:  On 5 December 2011, the Kepler space telescope discovered its first planet within the habitable zone or "Goldilocks region" of its Sun-like star.Kepler-22b is 2.4 times the radius of the earth and occupies an orbit 15% closer to its star than the Earth to the Sun.This is compensated for however, as the star, with a spectral type G5V is slightly dimmer than the Sun (G2V), and thus the surface temperatures would still allow liquid water on its surface.