Researchers have detected what looks like the presence of water in five exoplanets outside of the Milky Way.
One planet, dubbed HD209458b, had an "unusually puffed-up atmosphere" and also displayed the strongest sign of water, a NASA news release reported.
"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 in Greenbelt, Md., and lead author of an Astrophysical Journal paper, published today, describing the findings for 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."
The researchers used Hubble's Wide Field Camera 3 to look at the planets' atmospheres in a range of infrared wavelengths that would reveal if water was present. The scientists looked at the light absorption profiles of the various atmospheres, and are fairly confident they saw water.
"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," study leader L. Drake Deming of the University of Maryland, said.
The signal was there, but was weaker than the researchers would have expected. They believed this is because the planets are surrounded by dust or haze, which would distort the water molecules and change its appearance.
The planets are all hot Jupiters, which orbit very close to their host stars.
"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," Heather Knutson of the California Institute of Technology, a co-author on Deming's paper, said. "This suggests that cloudy or hazy atmospheres may in fact be rather common for hot Jupiters."
WATCH:
