Maps reveal clouds on distant exoplanet

Astronomers chart the atmosphere of Kepler-7b

CLOUD MAP Astronomers have made the first cloud map of an exoplanet. This artist’s conception of Kepler-7b (left), which has a radius 1.5 times that of Jupiter (right), shows what those clouds might look like.

JPL-Caltech/NASA and MIT

By Ashley Yeager

October 1, 2013 at 3:41 pm

On the gaseous exoplanet Kepler-7b, the forecast calls for clear skies in the east and high clouds in the west.

Although crude, the weather maps may be the first to identify clouds on a planet outside the solar system. In the future, a similar technique could help astronomers study clouds on Earth-like exoplanets.

While tracking light reflecting from the planet, astronomer Brice-Olivier Demory of MIT and colleagues found a particularly bright spot in Kepler-7b’s western hemisphere. The planet, located at least 1,000 light-years from Earth in the constellation Lyra, is too cool for heat from the planet’s surface to explain the vivid patch.

After ruling out other possibilities, the team concluded that starlight bouncing off clouds in Kepler-7b’s atmosphere could cause the bright spot. They report their findings September 30 in a paper posted on arxiv.org and accepted for publication in Astrophysical Journal Letters.

Combining infrared data from the Spitzer Space Telescope with visible-light data collected by the Kepler space telescope allowed the team to study Kepler-7b’s atmosphere.