For the first time ever, NASA has detected water vapor above the surface of Europa, a moon of Jupiter.
Scientists said that the amount of water vapor that could be detected was relatively small but it is tough to estimate it accurately without better instruments.
According to NASA:
Confirming that water vapor is present above Europa helps scientists better understand the inner workings of the moon. For example, it helps support an idea, of which scientists are confident, that there’s a liquid water ocean, possibly twice as big as Earth’s, sloshing beneath this moon’s miles-thick ice shell.NASA
The findings were reported in Nature Astronomy and were made by the Goddard Space Flight Center using the W. M. Keck Observatory in Hawaii.
Plumes were detected erupting from Europa in 2013 by the Hubble space telescope.
Why is Europa interesting?
Of Jupiter’s largest four moons, known as the Galilean moons, Europa is the smallest. However, it is still very large. Europa has enough water ice in its surface to support life if it were ever in liquid form. The entire planet is heated by the friction from tidal forces of Jupiter’s pull on it.
Because of this source of heat, it is possible that Europa could have a liquid ocean underneath its surface. So far, this is unconfirmed but the basic idea would be similar to this:
If Europa has a subsurface ocean with a source of heat, this would be enough to support certain types of life like we have on Earth. In the bottom of the oceans, far from any source of light, there are archaic forms of light which survive off heat from volcanic vents. A very similar process could be at work on Europa.
Also, because Europa is tidally locked with Jupiter, one side is always facing Jupiter making for what must be an astonishing view.