Friday, June 17, 2005

New Planet Discovered Orbiting Gliese 876

Update: (06/17/05 11:30 AM CDT) added to bottom of this post.

This is cool:

Arlington, Va.– Taking a major step forward in the search for Earth-like planets beyond our own solar system, a team of astronomers has announced the discovery of the smallest extrasolar planet yet detected. About seven-and-a-half times as massive as Earth, with about twice the radius, it may be the first rocky planet ever found orbiting a normal star not much different from our Sun. [...]
I am somewhat puzzled, though:

[...] The newly-discovered “super-Earth” orbits the star Gliese 876, located just 15 light years away in the direction of the constellation Aquarius. This star also possesses two larger, Jupiter-size planets. The new planet whips around the star in a mere two days, and is so close to the star's surface that its temperature probably tops 400 to 750 degrees Fahrenheit (200 to 400 degrees Celsius)—oven-like temperatures far too hot for life as we know it.
"This planet answers an ancient question," said team leader Geoffrey Marcy, professor of astronomy at the University of California, Berkeley. "Over 2,000 years ago, the Greek philosophers Aristotle and Epicurus argued about whether there were other Earth-like planets. Now, for the first time, we have evidence for a rocky planet around a normal star." [...]

Two planets in our own solar system are more closely related to Earth; Mars and Venus. I don't think a star as large as this new one, orbiting as close to it's star as it does, can be properly characterized as 'Earth-like' Also, Gliese 876 is an M-Dwarf type of star, unlike our own G2 sun. More star information than you probably want to know here..

Still, nit-picking aside, this is cool. Our abilities to reach out in scientific terms keep growing.

Update: It seem that there is reevaluation happening about the ability of planets of this type to harbor life. Over at the Speculist some discussion is happening:
[...] But now the SETI folks are reevaluating the possibility of habitable planets around small stars. [...]
Tidal lock, planetary systems, and defining of habitable zones... it's all there. Go read it.

Tagged as , , , , , , , , , ,