715

NASA announced Feb. 26, the discovery of 715 exoplanets (planets outside the Solar System) using data from the Kepler telescope.

The 715 exoplanets were discovered in 305 planetary systems. Four of the planets, each twice the size of the Earth, are in a "habitable zone" where surface temperatures would allow for liquid water. 

The addition of 715 exoplanets brings the known total to around 1,700. The first exoplanet was discovered in 1996.