Feb 22: Astronomers have discovered a set of seven Earth-sized planets orbiting a nearby star, three of them lying within its habitable zone with temperatures likely to be just right to harbour oceans of water and thus candidates to host life. The planets orbit a small ultracool dwarf star named TRAPPIST-1 about 40 light years from the solar system and are set to provide astronomers their first-ever opportunity to search for signs of life on exoplanets.