The extra-solar planetary search added a new success recently, Gliese 581 C. Gliese 581 is a red dwarf star located approximately 20 light years away, with two other planets already located in this solar system. It was first reported today by a European team headed by Stephane Udry of the Université de Genève. The compelling aspect to this is that Gl581C has an average surface temperature estimated between 0 and 40 Celsius — this means that the planet could have liquid water on its surface.

This is compelling because it is the first planet found to be within the so-called “habitable zone” of a star. As has been suggested, this makes the planet the first candidate for a search for extraterrestrial life, as it is the first terrestrial planet found within the habitable zone of a star. This is also the most Earth-like planet as yet discovered.

The discovery was reported in a pre-print of the article “The HARPS search for southern extra-solar planets” while SPACE.com reported on the discovery in the general media.