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Cambridge University Science Magazine
How was such a colossal cloud created? The planet, named GJ 436b, closely orbits a red dwarf star at a distance of less than 3 million miles causing 1 year to be a mere 2.64 Earth days. X-rays emitted from the red dwarf burn off approximately 1,000 metric tonnes of hydrogen from the planets atmosphere every second. The hydrogen gas accumulates as the red dwarf does not generate enough heat to dissipate it.  GJ 436b is believed to have lost up to 10% of its atmosphere and is likely to have lost its atmosphere at a greater rate when the star was at an earlier phase in its life cycle.

While GJ 436b is not at risk of loosing its entire atmosphere the discovery of The Behemoth may shed some light on to the formation of large rocky planets known as hot Super Earths. These versions of Earth found orbiting in close range to larger stars may be the remains of much bigger gaseous planets after their atmospheres have been completely burnt away.

The research was led by Dr David Ehrenreich based at the Observatoire de l'Université de Genève and was published in Nature on 25th June 2015. Image courtesy of NASA.

DOI: 10.1038/nature14501

Written by Holly Ironfield.