NASA's Hubble Telescope has picked out five exoplanets that appear to have signs of water in their atmospheres.

According to a NASA press release, two teams of scientists analyzed the signatures of water in the first study to compare the water signatures by profile and intensity. Previous studies have only reported the existence of water signatures.

"We're very confident that we see a water signature for multiple planets," said study lead author Avi Mandell, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "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."

The five planets were named WASP-17b, HD209458b, WASP-12b, WASP-19b and XO-1b and they each orbit a nearby star. The science teams published their findings in the Astrophysical Journal.

The stars had varying intensities of water. WASP-17b and HD209458b had the strongest signatures with dense and swollen atmospheres, while the other three had signs of water, but not to the same degree.

L. Drake Deming, of the University of Maryland, led the original study off which Mandell's is based. For the studies, the researchers made observations with infrared wavelengths that would reveal water signatures if they were to appear.

When comparing data, including profiles, intensities and consistency, both teams were confident they saw signals of water in the exoplanets' atmospheres.

"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 a co-author of Deming's paper, Heather Knutson, of the California Institute of Technology. "This suggests that cloudy or hazy atmospheres may in fact be rather common for hot Jupiters."

The latest discovery is another example of Hubble's incredible eye for detail and sheer power. Deming noted making these observations is no small feat, so a large task would require an exceptional telescope.

"To actually detect the atmosphere of an exoplanet is extraordinarily difficult," said Deming. "But we were able to pull out a very clear signal, and it is water."