Gliese 581 C: Earth-like Planet
Posted on April 27, 2007
A new planet called Gliese 581 C has been discovered by astronomers 20.5 light-years away from Earth. It is the most Earth-like planet to date according to the ESO. The planet has the potential to be habitable and it could harbor water and life according to Space.com.
Gliese 581 C is the smallest extrasolar planet, or "exoplanet," discovered to date. It is located about 15 times closer to its star than Earth is to the Sun; one year on the planet is equal to 13 Earth days. Because red dwarfs, also known as M dwarfs, are about 50 times dimmer than the Sun and much cooler, their planets can orbit much closer to them while still remaining within their habitable zones, the spherical region around a star within which a planet's temperature can sustain liquid water on its surface.
Because it lies within its star's habitable zone and is relatively close to Earth, Gliese 581 C could be a very important target for future space missions dedicated to the search for extraterrestrial life, said study team member Xavier Delfosse of Grenoble University in France.
"On the treasure map of the universe, one would be tempted to mark this planet with an X," Delfosse said.
Two other planets are known to inhabit the red dwarf system. One is a 15 Earth-mass "hot-Jupiter" gas planet discovered by the same team two years ago, which orbits even closer to its star than does Gliese 581 C. Another is an 8 Earth-mass planet discovered at the same time as Gliese 581 C, but which lies outside its star's habitable zone.
David Charbonneau, an astronomer at the Harvard-Smithsonian Center for Astrophysics (CfA), told Space.com that the fascinating find means, "there probably are many more such planets out there." Gliese 581 C also has an entry on Wikipedia.