WASHINGTON (AFP) – US astronomers said Wednesday they have discovered an Earth-sized planet that they think might be habitable, orbiting a nearby star, and believe there could be many more planets like it in space.
The planet, found by astronomers at the University of California, Santa Cruz, and the Carnegie Institution of Washington, is orbiting in the middle of the “habitable zone” of the red dwarf star Gliese 581, which means it could have water on its surface.
Liquid water and an atmosphere are necessary for a planet to possibly sustain life, even it it might not be a great place to live, the scientists said.
There are reports from Torino about HARPS observations of Gliese 581(g)
Vogt et al reported on additional possible planets in the multi-planet low mass Gliese 581(g) system.
In particular they showed a ~ 3 sigma detection of a possible 3+ earth mass planet in a circular orbit with an orbital period consistent with a temperate surface.
The paper used a combination of historic Keck data, published HARPS data up through 2008 and new high cadence Keck data.
There was some concern when the paper came out that the False Alarm Probability was underestimated (see Cumming et al for discussion of False Alarm Probability estimates and general considerations ).
Shucks! All those nice water bearing planets and now fuddy-duddies have go on about false-probably alarms and sigma detections.
Of course, that’s where real science happens.