NASA probe discovers bigger, older cousin to Earth

NASA's Kepler mission has confirmed the first near-Earth-size planet in the "habitable zone" around a Sun-like star.

This discovery and the introduction of 11 other new small habitable zone candidate planets mark another milestone in the journey to finding another "Earth", the US space agency said in a statement.

The newly discovered Kepler-452b is the smallest planet to date discovered orbiting in the habitable zone -- the area around a star where liquid water could pool on the surface of an orbiting planet -- of a G2-type star, like our Sun.