Hubble Telescope Reveals Cloudy Weather on Alien Super-Earth

It's a new look at an alien world. Scientists have used the Hubble telescope to peer at the clouds of exoplanet GJ 1214b, reveal a little bit more about this super-Earth and its weather patterns.

The planet is classified as a super-Earth since its mass is intermediate between those of Earth and Neptune. It was first discovered in 2009 by the MEarth Project, which monitors two thousand red dwarf stars for transiting planets. It's located just 40 light-years from Earth, in the direction of the constellation Ophiuchus. It transits in front of its parent star every 38 hours, which gives scientists plenty of opportunities to study its atmosphere as starlight filters through it.

Super-Earths like GJ 1214b are actually one of the most common types of planets in the Milky Way galaxy. Yet because none of these planets exist in our own solar system, the physical nature of these planets is largely unknown.

That's why scientists decided to take a closer look using the Hubble telescope. They precisely measured the spectrum of the planet in near-infrared light. In all, the researchers used 96 hours of telescope time over 11 months, making this the single largest Hubble program ever devoted to studying a single exoplanet. This allowed them to detect definitive evidence of high clouds blanketing the planet. The composition of these clouds are currently unknown, yet models predict that they could be made out of potassium chloride or zinc sulfide. Yet while these clouds are interesting, they also hide any information about the composition and behavior of the lower atmosphere and the surface.

"We really pushed the limits of what is possible with Hubble to make this measurement," said Laura Kreidberg, one of the researchers, in a news release. "This advance lays in the foundation of characterizing other Earths with similar techniques."

The findings could help pave the way for locating potentially habitable, Earth-like planets beyond our solar system in the future.

The findings are published in the journal Nature.