Scientists have identified 45 rocky planets beyond the solar system that orbit within habitable zones where liquid water could exist.
The findings come from a team led by Professor Lisa Kaltenegger of the Carl Sagan Institute.
Researchers analysed data on more than 6,000 planets outside the solar system and found 45 that are both rocky and located in the habitable zone of their stars.
The team used information from the defunct Gaia mission of the European Space Agency and NASA’s Exoplanet Archive. They calculated how much energy each planet receives from its parent star, a key factor in determining whether liquid water could exist on the surface.
Scientists said Earth lies within the habitable zone of the sun, while Venus and Mars sit near the inner and outer edges of that zone. Applying the same limits to other star systems produced 45 possible planets in the broader habitable zone, including 24 in a narrower, more conservative range.
Among the most promising are the planets of the TRAPPIST-1 system, which orbits a red dwarf star about 40 light-years from Earth. Study co-author Gillis Lowry has focused on TRAPPIST-1 e and TOI-715 b, a super-Earth in the conservative habitable zone.
Other notable candidates include Proxima Centauri b and LHS 1140 b.
The planets are now being studied by next-generation observatories, including the James Webb Space Telescope, the Extremely Large Telescope and the Habitable Worlds Observatory. Scientists cautioned that being in a habitable zone does not prove life exists, but said it is the starting point in the search.