Kepler spots five new alien planets in the 'habitable zone'

NASA has announced that their planet-hunting spacecraft, Kepler, has discovered 1,235 potential new planets around alien stars. Of these, five of them are about the right size, and in about the right place, to potentially support life.

The Kepler spacecraft was launched specifically to search for planets around other stars, and so far, it seems to be doing a bang-up job. While it can't see other planets directly, it watches their stars for little dips in brightness that occur when the planets pass between the star and Kepler. From this data, Kepler can tell about how big the the planet is, where it orbits, how hot it is, and even what it's made of.

Discovering inhospitable gas giants around other stars is old news nowadays, but five of these new planets are in the habitable zone, meaning that they're located a comfortable distance from their star, they're not too hot and not too cold, and liquid water could be stable on their surfaces. Also, they're about the same size as Earth, implying a friendly sort of gravity. Of course, we have no idea (yet) what the surfaces of these planets are actually like, but so far, all signs point to class M.

Kepler has also found a pretty wild multi-planet system, consisting of six planets, five of which somehow manage to orbit their star (a yellow dwarf) closer than Mercury orbits the sun. Astronomers didn't know that such a system was physically possible until they found one. It's not likely that any of these planets support life, but it's the first indication that solar systems like ours may not be entirely unique.

So what's the next step? Well, Kepler is going to keep looking for planets, and as soon as we can figure out a way of telling whether the promising ones have breathable atmospheres and friendly aliens who just want to help you have a good time, we can send an interstellar scoutship out there to make first contact.

Via NASA, 2
