The atmosphere around a super-Earth exoplanet has been studied for the first time by an international team of astronomers utilising ESOs Very Large Telescope. The planet, which is cognized as GJ 1214b, was examined as it passed before of its parent star and some of the starlight passed through the planets atmosphere. We now recognize that the atmosphere is either mostly water in the form of steam or is dominated by thick clouds or hazes.
In advance of the new observations, astronomers had proposed three possible atmospheres for GJ 1214b. The first was the intriguing theory that the planet was shrouded by water, which, given the close proximity to the star, would be in the form of steam. The second hypothesis was that this is a rocky world with an atmosphere consisting mostly of hydrogen, but with high clouds or hazes obscuring the view. The third option was that this exoplanet was like a mini-Neptune, with a small rocky core and a deep hydrogen-rich atmosphere.
super-Earth exoplanet GJ 1214b
