Newfound Planet Has Earth-Like Orbit

Raver32 writes with a link to the Space.com site, and an article discussing an extra-solar planet that looks a lot like ours from a distance. At least, its orbit does. The planet is located about 300 light years away, in the constellation Perseus. It circles its giant red star every 360 days and was discovered by 'looking for wobble', the shift in a star's movement that hints at orbiting planets. "The discovery could help astronomers understand what will happen to our sun's brood of planets when it exhausts its store of hydrogen fuel and its outer envelope begins to swell. When that happens in an estimated 5 billion years, our sun will be so big that it will engulf the inner planets and most likely Earth. But long before that happens, life on our planet will have perished and its seas will have boiled away."

Comments

Life will be there after the oceans boil away

[InterGuru]

A Princeton-led research group has discovered an isolated community of bacteria nearly two miles underground that derives all of its energy from the decay of radioactive rocks rather than from sunlight.

Subterrainian Microbes

This type of bacterium, approximately four micrometers in length, has survived for millions of years on chemical food sources that derive from the radioactive decay of minerals in the surrounding rock, making it one of the few creatures known that does not depend on sunlight for nourishment.

These will survive any surface conditions, until the heat penetrates two miles deep.

Not going to engulf Earth

[teslar]

When that happens in an estimated 5 billion years, our sun will be so big that it will engulf the inner planets and most likely Earth.

Actually, this is incorrect. It will engulf the orbits. The planets themselves will just escape to wider orbits. Except Mercury, Mercury's pretty much buggered.

More Red Giant trivia at Wikipedia.

... No.

[Cairnarvon]

Just because it orbits in 360 days doesn't mean it has an Earth-like orbit.

Earthlike? Not likely...

[_mythdraug_]

Earthlike in that it takes approximately the same number of days? Yes.

Earthlike in any other way? Not likely.

The Bad Astronomer had a nice examination of this article earlier today.

Re:Earthlike? Not likely...

[The Bad Astronomer]

Well, thanks for the link love. I don't mean to downplay the discovery; it's very cool, and we're one-by-one building an actual catalog of extrasolar planets, which means we can do taxonomy on them. How cool is that? I just want people to understand that there ain't nothing Earthlike about the planet, so that we don't get people running around overblowing this news.

Re:Change in Orbit

[pauljlucas]

Actually, I have read that the earth may be pushed out to a farther orbit, so we wouldn't get 'swallowed' by an expanding sun.

Right, because the sun will blow off mass into space. A less-massive sun will have weaker gravity so everything in orbit will move farther out.

But it probably won't matter much because the sun as a red giant will be far hotter and far more luminous so the orbital distance increase won't be enough to compensate.