Scientists Have Found Water On Jupiter's Moon, Raising Chances Of Finding Alien Life

The search for extraterrestrial life is something that has consumed man ever since we first spotted other planets in our vicinity.

We've not found any life, but we're now better at understanding where it might be. And it might be on Jupiter's moon.

Images courtesy: NASA

Back in 2016, NASA's Hubble Space Telescope spotted what looked like plumes of some sort of gas erupting from the surface of Jupiter's moon Europa. At the time, they posited that it could be plumes of water vapour, which could hold promise for signs of life. Now, the space agency has been able to confirm that the plumes are indeed water vapour.

"While scientists have not yet detected liquid water directly, we've found the next best thing: water in vapor form," study lead author Lucas Paganini, a planetary scientist at NASA's Goddard Space Flight Center, said.

Paganini and his colleagues used the WM Keck Observatory in Hawaii to study the 3,100km-wide Europa. They observed the moon for 17 nights, from February 2016 through to May 2017. On one of those nights, April 26 in 2016, they spotted the characteristic emission of infrared light, indicating that the plume was indeed water vapour.

And it wasn't a little poof of a spray either. The team estimated the plume held about 2,095 metric tons of water, almost enough to fill an Olympic-size swimming pool. Europa is thought to largely consist of a huge salty ocean buried beneath an icy shell, and that amount of water in plume is more than would occur from water molecules being stripped from the surface by cosmic radiation. Additionally, that stripping would be visible more often than they saw, which lends credibility to the theory of a buried ocean on Europa.

That theory is why astrobiologists have long considered it one of the best bets for us to find alien life in our solar system. "Essential chemical elements (like carbon, hydrogen, oxygen, and more) and sources of energy, two of three requirements for life, are found all over the solar system," said Paganani. "But the third - liquid water - is somewhat hard to find beyond Earth. Now that there is almost concrete proof of water on Europa however, its chances of hosting alien life just skyrocketed.

In fact, astrobiologists are incredibly excited about plumes like these because it's a way for them to get "free samples". Essentially, if we can get a robotic probe to Europa's orbit, it can collect any possible DNA matter that's thrown up into space along with the water in the plume. That makes hunting for life on the moon that much easier.

In fact, NASA is working on a mission to do just that. The Europa Clipper is scheduled to launch mid-2020 and, though it will orbit Jupiter, it will attempt to study Europa up close through dozens of flybys. The mission will be analysing the moon's surface and subterranean ocean, as well as looking for a good spot to land an alien-hunting probe in the future. And if Clipper manages to fly through one of those plumes, we could get data about life on Europa even sooner than that.