Ross 128b was found orbiting a red dwarf 11 light years away from our own planet and is moving closer to us.
Scientists say its surface temperature may be ‘the closest known comfortable abode for possible life’.
Astronomers working with the European Southern Observatory’s High Accuracy Radial velocity Planet Searcher (HARPS) at the La Silla Observatory in Chile found that the red dwarf star Ross 128 is orbited by a low-mass ‘exoplanet’ every 9.9 days.
The Earth-sized world is expected to be temperate, with a surface temperature that may also be close to that of the Earth. Ross 128 is the ‘quietest’ nearby star to host such a temperate exoplanet.
Study co-author, Dr Nicola Astudillo-Defru, of the University of Geneva in Switzerland, said: ‘This discovery is based on more than a decade of HARPS intensive monitoring together with state-of-the-art data reduction and analysis techniques.
‘Only HARPS has demonstrated such a precision and it remains the best planet hunter of its kind, 15 years after it began operations.’