Images of an exoplanet show signs of a water-rich atmosphere, Japanese scientists say. Discovered in 2009, the planet, Gliese 1214b, is located in the Ophiuchus constellation, some 40 light years from Earth.
About 2.7 times larger than Earth, Gliese 1214b is considered a super-Earth: an exoplanet larger than Earth but smaller than some of our solar system's giants, such as Uranus and Neptune.
Scientists are still trying to determine if the atmospheres of super-Earths have more in common with Earth -- and are therefore comprised mostly of water -- or with our planetary neighbors, which would mean it is a hydrogen atmosphere.
The Japanese scientists studied images captured by the Subaru Telescope's two cameras. They were looking for signs of Rayleigh scattering: the patterns that form when light is scattered by particles that are smaller than the wavelength of light they're traveling through. If the images showed Rayleigh scattering, that would have indicated a hydrogen atmosphere.
Because these images did not show Rayleigh scattering, the scientists say they are fairly certain that Gliese 1214b has a water-rich atmosphere. The researchers plan to continue studying satellite images to test the validity of their conclusion.
If the atmosphere is indeed water-rich, it will help explain how super-Earths form, and why there are no super-Earths within our solar system.