A hard rain's gonna fall on exoplanet COROT-7b

This artist's impression shows sunrise over CoRoT-7b(Credit: ESO/L)

Raining rocks? The concept may not be as preposterous as it sounds according to scientists at Washington University in St Louis who have theorized that a recently-discovered exoplanet, COROT-7b, may have an atmosphere that does exactly that.

We have previously covered extrasolar planets, or exoplanets as they are more widely known, several times here at Gizmag and to date 374 of them have been discovered. Most of these have been detected through radial imaging or other indirect methods rather than actual imaging. COROT-7b was discovered last February by the COROT space telescope, and in August this year a second planet named COROT-7c was discovered to be orbiting the dwarf star COROT-7.

Using data from both planets, 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. But 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.

With the confirmation of nearly 400 exoplanets in just over 20 years, it will be interesting to see what phenomena the universe reveals to us next.

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