Astronomers have created the first map of the clouds on a planet outside our Solar System. The planet is Kepler-7b, a large gaseous world like Jupiter that lives approximately 1,000 light-years away.
Researchers used data from Nasa's Spitzer and Kepler space telescopes to study the exoplanet, which orbits close to its parent star. Their results suggest the hot giant is marked by high clouds in the west and clear skies in the east.
Findings have been accepted for publication in the journal Astrophysical Journal Letters. Co-author Brice-Olivier Demory of Massachusetts Institute of Technology says, "By observing this planet with Spitzer and Kepler for more than three years, we were able to produce a very low-resolution 'map' of this giant, gaseous planet". He also explains that they wouldn't expect to see oceans or continents on this type of world, but they have detected a clear, reflective signature that is interpreted as clouds.
The Kepler telescope's visible-light observations of this distant world's moon-like phases led to a rough map of the planet that showed a bright spot on its western hemisphere. But these data were not enough on their own to decipher whether the bright spot was coming from clouds or heat. The team used Spitzer to gather further clues about the planet's atmosphere. They determined that light from the planet's star was bouncing off cloud tops located on the west side of Kepler-7b.
Kepler-7b reflects much more light than most giant planets we've found, which we attribute to clouds in the upper atmosphere," said Thomas Barclay from Nasa's Ames Research Center in Moffett Field, California, US, who works on the Kepler telescope team.
"Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time - it has a remarkably stable climate."
Although the Kepler mission has now ended because of problems with the spacecraft's reaction wheels, astronomers are still studying the data it gathered. The mission has so far discovered more than 150 bonafide exo-planets and thousands of other candidate worlds, so there are still new explorations to come shortly.