Scorching hot exoplanet 'snows' sunscreen

Artist’s illustration showing the scorching-hot exoplanet Kepler-13Ab, which orbits very close to its host star, Kepler-13A.

Astronomers have observed an extrasolar planet with some of the weirdest weather conditions ever seen.

Six times more massive than Jupiter and situated at a distance of 1,730 light years from the Earth, Kepler-13Ab, with often sees dayside surface temperatures of up to 5,000 degrees Fahrenheit, is one of the hottest extrasolar planets ever discovered,

 Kepler-13Ab is "tidally locked," always showing the same face to its star. So, it has a dayside and a nightside.)

Situated extremely close to its parent star and with an orbital period of 1.8 Earth days, this distant world is tidally locked so that one side of the planet is always facing its star.

Now astronomers believe that strong winds may also carry titanium dioxide - one of the active ingredients in sunscreen - around to the planet's cooler side where it condenses in to clouds.

The peculiar 'snow' then falls in to the lower atmosphere where it stays due to the planet's gravity.

"These observations of Kepler-13Ab are telling us how condensates and clouds form in the atmospheres of very hot Jupiters, and how gravity will affect the composition of an atmosphere," said study lead author Thomas Beatty from Pennsylvania State University.

"When looking at these planets, you need to know not only how hot they are, but also what their gravity is like."

"In many ways, the atmospheric studies we're doing now on these gaseous, 'hot Jupiter' kinds of planets are test beds for how we're going to do atmospheric studies of terrestrial, Earth-like planets," he said in the same statement. "Understanding more about the atmospheres of these planets and how they work will help us when we study smaller planets that are harder to see and have more-complicated features in their atmospheres." 

As its name suggests, Kepler-13Ab was discovered by NASA's planet-hunting Kepler space telescope, back in 2011. The planet is part of a triple-star system that includes the hot Jupiter's host star, Kepler-13A, and two companion stars (Kepler-13B and Kepler-13C).