U.S. researchers say they've used the Hubble Telescope to reveal the weather on an alien world, and the forecast is for clouds, clouds and more clouds. A team led by scientists in the Department of Astronomy and Astrophysics at the University of Chicago report they have definitively characterized the atmosphere of a super-Earth class planet orbiting another star for the first time. Classified as a super-Earth type planet because its mass is between those of Earth and Neptune, the studied planet, known as GJ1214b, has shown clear evidence of clouds in its atmosphere in images from Hubble. The observations used 96 hours of telescope time spread over 11 months, the largest Hubble program ever devoted to studying a single exoplanet, a University of Chicago release said Friday. "We really pushed the limits of what is possible with Hubble to make this measurement," graduate student and study first author Laura Kreidberg said. "This advance lays the foundation for characterizing other Earths with similar techniques." Because of its proximity to our solar system -- just 40 light-years from Earth -- GJ 1214b is the most easily observed super-Earth. The clouds in its atmosphere could be made out of potassium chloride or zinc sulfide at the scorching temperatures of 450 degrees Fahrenheit found on GJ 1214b, the researchers said. "You would expect very different kinds of clouds to form than you would expect, say, on Earth," Kreidberg said.