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Hey, George Clooney. LOST in SPACE... and thirsty? Visit these 5 ALIEN worlds*

Hubble spots traces of water in the atmospheres of hazy hot Jupiters

Seven worlds in the Habitable Exoplanets Catalog

Boffins using NASA's Hubble Space Telescope have spotted faint signs of water on five distant planets orbiting stars beyond our Solar System.

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The presence of atmospheric water on a few exoplanets has been seen before, but the new study had been able to measure how much water there is on the multiple worlds.

Two of the planets, WASP-17b and HD209458b, had the strongest signs of H2O, while the other three worlds - WASP-12b, WASP-19b and XO-1b - are all consistent with water.

"We're very confident that we see a water signature for multiple planets," said Avi Mandell, a planetary scientist at NASA's Goddard Space Flight Center and lead author on the study of WASP-12b, WASP-17b and WASP-19b.

"This work really opens the door for comparing how much water is present in atmospheres on different kinds of exoplanets, for example hotter versus cooler ones."

Mandell's team and a second group of scientists studying the other two worlds used Hubble's Wide Field Camera 3 to look at details of the absorption of light in the planets' atmospheres. The teams compared the shape and intensity of the absorption profiles in a range of infrared wavelengths to spot water signatures.

"To actually detect the atmosphere of an exoplanet is extraordinarily difficult. But we were able to pull out a very clear signal, and it is water," said L Drake Deming of the University of Maryland, whose team reported results for HD209458b and XO-1b.

However, sadly the water signals were all less pronounced than expected, which the scientists believe may be because all of the alien worlds are covered in a layer of dust. This haze reduces the intensity of the signals from the atmosphere – in the manner that fog reduces visibility – and also alters the profiles of water and other important molecules.

None of the planets are candidates for immediate colonisation either, as all five are hot Jupiters - massive worlds orbiting close to their suns.

"These studies, combined with other Hubble observations, are showing us that there are a surprisingly large number of systems for which the signal of water is either attenuated or completely absent," said Heather Knutson of CalTech, a co-author on Deming's paper. "This suggests that cloudy or hazy atmospheres may in fact be rather common for hot Jupiters."

Both papers were published in the Astrophysical Journal. ®

* Yes, we know in the movie he was at the Hubble Space telescope and nowhere near the exoplanets in question... and there's no certainty there's water on them, et cetera... Don't be a buzzkill

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