Chilean telescope discovers three planets

"The planet closest to the star is probably rocky and the farthest is the first exoplanet of that mass that is in the habitable zone of its star, meaning, where water could be found in liquid form," the observatory said in a news release. An exoplanet is a planet that orbits a star other than the sun.

"It's the first discovery of a planetary system made up of various planets of a Neptune-type mass," said Christophe Lovis, astronomer with Switzerland's Observatory of Geneva, said in the news release.