GLiese 581 c
I became very aware how weak my knowledge of astronomy is when the story came out last week about a "superplanet" orbiting the "red dwarf" star GLiese 581. Approximately five times as large as Earth in mass, the planet GLiese 581 c is particularly significant from a human perspective because it is the only known planet outside of Earth which falls within the "habitable zone" of surface temperatures low enough so that water may occur in liquid form.
The discovery of GLiese 581c was made by a team of Swiss, French and Portuguese astronomers using a telescope in La Silla, Chile1, 2, 3. The planet's existence is known at this point from its apparent effects upon the motion of GLiese 581. It will not be given its own name as a planet until it is directly imaged. The above is an artist's reconstruction, looking toward the star GLiese 581 past a possible moon.
In addition to the story on NPR3, I was initially educated about GLiese 581c by Sabine of Germany. Sabine's post is based upon several stories from Europe and has some excellent graphics. Blogger Chris Rowan is less impressed with the GLiese 581 c story, remarking that this is actually one of at least three planets orbiting GLiese 581 and liquid water has not actually been discovered yet.
1Sanderson, Katherine, 2007, The most Earth-like planet yet: Extrasolar planet grabs attention of astronomers and alien-hunters. Nature (online), 25 April.
2Klapper, Bradley S., 2007, Swiss Scientist: Search for Life Next. Washington Post, 26 April.
3Boyce, Nell, 2007, Earth-Like Planet discovered in Libra. National Public Radio, 25 April.