New Research Shows Promise for Studying Jupiter’s Moon Europa in More Detail

For twenty years, Jupiter’s moon Europa has been seen as one of the most intriguing places in the solar system. Scientists believe its icy surface hides a vast liquid ocean and say there’s a chance microbial life could thrive in that ocean. However, the same ice shell that would protect any life below it is what prevents efforts to figure out what’s going on.

But now, scientists may have found a way to circumvent that challenge. In a paper published yesterday by the journal Nature Astronomy, a team presents evidence that a spacecraft has already flown through a jet of liquid rising from Europa’s surface. It’s hard not to dream that such a plume would carry any life up to where human instruments could study it more easily.

Luckily, NASA already has plans to visit the moon, with a mission set to launch in the 2020s. Even before the new results were made available, a congressman used them to make the case for giving the mission extra funding.

This new finding is actually based on old data, collected by the Galileo spacecraft, which examined Jupiter and its moons in the 1990s and early 2000s. Scientists went back to that data after a few images taken by the Hubble Space Telescope and published over the past five years appeared to suggest something was spewing off Europa’s surface.

First author Xianzhe Jia, a planetary scientist at the University of Michigan, was listening to a conference presentation that talked about all those papers in tandem. That’s when he started to wonder whether Galileo might have accidentally flown over any of these areas and, if so, whether it had reported anything interesting.

Jia and his team found that during Galileo’s closest skim over the moon’s surface, in December 1997 and less than 250 miles up, the spacecraft had actually discovered something odd. The magnetic field and charged particles around the moon were in upheaval in a way that suggested a plume of neutral particles spilling out into space—just the sort of signal Jia had been hoping for. Now, the hope is that Galileo’s planned successor, Europa Clipper, forewarned and forearmed, will be able to confirm the plumes are there and learn more about them.

It is still unclear for scientists what precisely could cause plumes on Europa. But one possibility is that they’re created by the huge tug of Jupiter’s gravity.

Lynnae Quick, a geologist at the Smithsonian National Air and Space Museum who was involved in the Clipper mission but not in this paper, told Newsweek that this could cause some fractures on Europa to open and close during its orbit so you may have material that’s jetted into space.

Since Europa is quite big, its own gravity wouldn’t let the material spew too far, which would explain why Galileo detected anything unusual only during its closest approach.

If the plumes are confirmed, that will make Europa the second moon in our solar system to sport such features. In 2005, scientists announced that at the south pole of Saturn’s moon Enceladus, giant plumes of salty water rush out into space. That finding rested in part on similar data about the magnetic field data, but since the Cassini spacecraft was still around when Enceladus’s plumes were found, scientists could examine them in much greater detail.

The next step for the team is to figure out exactly what that plume is composed of, where it’s coming from and if it actually suggests Europa has life.

References: https://bit.ly/2GdaCVx

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