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

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