International boffins, poring over the results from mighty telescopes both spacegoing and ground-bound, say they have identified at least 16 potentially habitable Earth-like planets orbiting other stars: and at least 30 potentially habitable moons along the lines of the scientifictional Endor and Pandora, orbiting planets in other solar systems.
The news comes in a press statement issued by the Planetary Habitability Laboratory of the University of Puerto Rico, outlining the new Habitable Exoplanets Catalogue compiled by its scientists. The catalogue rates each exoplanet on its chances of being able to harbour life along Earthly lines, which requires various things such as temperatures where liquid water can exist, a protective magnetic field to keep off the space radiation etc.
"One important outcome of these rankings is the ability to compare exoplanets from best to worst candidates for life", says Abel Méndez, Director of the Laboratory and principal compiler of the catalogue.
"New observations with ground and orbital observatories will discover thousands of exoplanets in the coming years. We expect that the analyses contained in our catalog will help to identify, organize, and compare the life potential of these discoveries."
According to Méndez and his colleagues analysis of data from sources including NASA's Kepler space telescope, among thousands of known exoplanet candidates and hundreds of confirmed planets, only a few are strong candidates to be habitable:
Only two confirmed exoplanets so far match the criteria for habitability in the catalog, Gliese 581d and HD 85512b, both still marginally Earth-like. However, the catalog identifies over 15 exoplanets and 30 exomoons as potential habitable candidates. Future observations with new instruments, such as the proposed NASA Terrestrial Planet Finder (TPF), will be necessary to confirm the suitability for life of any of these candidates.
Gliese 581d and HD 85512b are both well-known as promising places for life already, and we here on the Reg interstellar-affairs desk have also reported on strong prospects for exomoons before this. According to the new Catalogue, due to go online shortly here, there are also 30 exomoons and 8 "warm terrans" - earth-size planets in their star's liquid water zone - plus a further 8 "warm superterrans" - bigger planets in the liquid water zone - now known.
More detail is expected in a NASA briefing later in the day: we'll keep you posted. ®