According to the researchers, including those from the University of Geneva in Switzerland, the giant exoplanet WASP-76b is at a distance that would take even light 640 years to reach the Earth, and has a day side where temperatures climb above 2400 degrees Celsius — high enough to vaporise metals.
The study noted that strong winds carry iron vapour to the cooler night side where it may be condensing into iron droplets.
“One could say that this planet gets rainy in the evening, except it rains iron,” said study co-author David Ehrenreich, a professor at the University of Geneva in Switzerland. The researchers said this phenomenon happens because the ‘iron rain’ planet only ever shows one face— its day side— to its parent star, while its cooler night side remains in perpetual darkness.
They explained that like the Earth's Moon, WASP-76b is ‘tidally locked’, meaning it takes as long to rotate around its axis as it does to go around the star.