NASA Confirms Its First Planet in Habitable Zone of Sun-like Star
Kepler has certainly made a lot of discoveries. It should be fairly clear to us now that planetary systems are pretty common and, by extension, sentience must (by sheer odds) be out there too.<p>But I have to wonder how many assumptions go into this so-called "habitable zone". Doesn't it greatly depend on the atmospheric composition? With a different atmosphere, couldn't Venus be habitable (actually it might be in our Sun's habitable zone)? If Mars were larger, couldn't it support the kind of atmosphere that would allow liquid water.<p>Particularly if such planets were geologically active.<p>Even if all this stacks up, at 600 light years away, like pretty much any other star system, this planet is across a gulf I'm not sure we'll ever cross, which is a somewhat depressing thought.