Two planets in unusual star system are very likely habitable, scientists say

Exoplanets orbiting Trappist-1 have thrilled astronomers since their discovery last year thanks to their Earth-like potential to harbor water

Scientists have identified two planets circling round a dim dwarf star as especially likely candidates to have habitable conditions, with probable water and a source of heat, attributes thought necessary for life beyond Earth.

Since their discovery last year, the seven planets and their star, called Trappist-1, have thrilled astronomers hunting for a world resembling Earth. Never before had scientists found so many Earth-sized planets around a single star, or in a zone where the extreme temperatures of space would not obliterate the chances of life.