Patchy clouds in the west and clear skies in the east. That is the current weather forecast, not for anywhere on Earth, but for a much more distant world in another solar system. For the first time, astronomers have been able to map cloud patterns on such a far-away exoplanet, it was announced on September 30, 2013.
The findings come from data provided by the Kepler and Spitzer space telescopes. An amazing accomplishment, considering how incredibly far away this planet, Kepler-7b, is. Kepler-7b is a gas giant world, about 1.5 times larger than Jupiter. It orbits very close to its star, with estimated temperatures of between 815 ˚C – 982 ˚C (1,500 ˚F – 1,800 ˚F).
According to Brice-Olivier Demory of Massachusetts Institute of Technology in Cambridge, “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. We wouldn’t expect to see oceans or continents on this type of world, but we detected a clear, reflective signature that we interpreted as clouds.”
The initial observations of Kepler-7b by Kepler indicated a bright spot in its western hemisphere, but what caused it was unknown. Follow-up observations by Spitzer revealed it to be light reflecting off cloud tops.
While this planet does have cloud patterns reminiscent of those on Earth, they don’t seem to be as active. As Thomas Barclay, a Kepler scientist at NASA’s Ames Research Center explained, “Kepler-7b reflects much more light than most giant planets we’ve found, which we attribute to clouds in the upper atmosphere. Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time – it has a remarkably stable climate.”
As technology progresses, it will be interesting to see what types of clouds and weather patterns are found on many of the other thousands of exoplanets now being discovered.