NASA’s super-Earth characterization could help find life on other planets
By ANIThursday, December 2, 2010
LONDON - Using a ground-based telescope, a team of astronomers, including two NASA Sagan Fellows, has made the first characterizations of a super-Earth’s atmosphere.
A super-Earth is a planet up to three times the size of Earth and weighing up to 10 times as much.
The findings are a significant milestone toward eventually being able to probe the atmospheres of Earth-like planets for signs of life.
The team determined the planet, GJ 1214b, is either blanketed with a thin layer of water steam or surrounded by a thick layer of high clouds.
“This is the first super-Earth known to have an atmosphere,” said Jacob Bean, a NASA Sagan Fellow and astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
“But even with these new measurements, we can’t say yet what that atmosphere is made of. This world is being very shy and veiling its true nature from us.”
GJ 1214b is 2.7 times the size of Earth and 6.5 times as massive. It has a low density for its size, leading astronomers to conclude the planet is some kind of solid body with an atmosphere.
Bean and his team observed infrared light as the planet crossed in front of its star. During such transits, the star’s light filters through the atmosphere. Gases absorb the starlight at particular wavelengths, leaving behind chemical fingerprints detectable from Earth.
In the case of the super-Earth, no chemical fingerprints were detected; however, this doesn’t mean there are no chemicals present. Instead, this information ruled out some possibilities for GJ 1214b’s atmosphere, and narrowed the scope to either an atmosphere of water steam or high clouds.
Astronomers believe it’s more likely that the atmosphere is too thin around the planet to let enough light filter through and reveal chemical fingerprints.
“This is an important step forward, narrowing our understanding of the atmosphere of this planet. Bizarre worlds like this make exoplanet science one of the most compelling areas in astrophysics today,” said NASA Exoplanet Exploration Program Scientist Douglas Hudgins. (ANI)
