Scientists were able to conclude that COROT-7b has a similar density and silicate rock makeup to that of Earth. However, the planet and its host star are separated by only 1.6 million miles, which is 23 times less than the distance between our Sun and Mercury. With an orbit much like our Moon's around Earth, one side of COROT-7b always faces towards its Sun, and this side is thought to have a temperature of 4220°F.
As rocks vaporize at that heat it is believed that COROT-7b's precipitation is pebbly. When a "front moves in" pebbles condense out of the air and run into lakes of molten lava on the surface below. Scientists used a computer system that ran different variants yet yielded consistent results - rock showers.
Much like the Earth's atmosphere causes water cloud to form resulting in water droplets, COROT-7b's atmosphere is believed to form rock clouds that then rain little pebbles and other forms of rock.
A hard rain's gonna fall on exoplanet COROT-7b
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