Alien Planet May Be in Habitable Zone After All

The orbits of planets in the Gliese 581 system are compared to those of our own solar system. The Gliese 581 star has about 30 percent the mass of our sun, and the outermost planet is closer to its star than we are to the sun. Gliese 581d might be able to sustain liquid water on its surface.

 

 

The alien planet Gliese 581g has been getting a lot of attention recently as a possibly habitable world, but a case is building for its next-door neighbor as a good candidate for extraterrestrial life, too.

Gliese 581d, another planet discovered around the star Gliese 581, may well lie in the "habitable zone" of the star — that just-right distance range that can allow liquid water to exist — new atmospheric-modeling research suggests. The finding follows closely on the heels of a similar study, published earlier this year, that reached the same provisional conclusion.

"The fact that two models find conditions for liquid water could exist, that strongly implies that it is possible," said the new study's lead author, Philip von Paris of the Institute for Planetary Research at the German Aerospace Center in Berlin. "It doesn't seem impossible to have life there." Space.com