Scientists Plan to look for Alien Life on Europa

Are we truly alone in the universe? Or is Earth just one of many inhabited worlds? These are some of the most fascinating questions facing humanity, and soon, thanks to a 2016 federal budget allocation for a mission to Jupiter's moon Europa, NASA may be able to help answer them.But first scientists must figure out how to actually detect life on the world, whose frozen outer shell conceals an immense ocean of salt water that many think is our best chance for finding other life in our solar system. That challenge motivated a workshop held Wednesday in California at NASA's Ames Research Center, where planetary scientists and those who study the potential for alien life, called astrobiologists, gathered to discuss strategies for finding life on Europa.

"Europa is clearly such a prime target for astrobiology that having a workshop like this to try and figure out all the ways in which we could possibly sample its ocean  critically important," said Kevin Hand, an astrobiologist at California's Jet Propulsion Laboratory, who was at the meeting.Roughly the size of Earth's moon, Europa is structurally like a liquor-filled chocolate, with a liquid ocean that could be 62 miles (100 kilometers) deep standing in for the cherry brandy. Scientists have long thought that that sea is one of the best potential alien incubators in our solar system. But it wasn't until recently that sending a spacecraft to study it became more than a theoretical possibility.

Now, in a move that has astrobiology researchers buzzing in excitement, the 2016 federal budget request includes funds for the first phase of a Europa mission. NASA administrators are optimistic that such a mission will happen—even though it might not launch until the 2020s. "We are going to do a Europa mission, and I'm very excited about that," said John Grunsfeld, a former astronaut who is now NASA's associate administrator for the science mission directorate. "I think it's unlikely that Congress is going tell us, 'No, NASA shouldn't be doing a Europa mission.' Very unlikely."

The current mission concept, called the Europa Clipper, would cost an estimated $2.1 billion and could launch as early as 2022. As planned, the mission will send a spacecraft to orbit Jupiter and brush by Europa about four dozen times over three and a half years, snapping photos and taking a good, close look at the moon.

One of the wilder ideas is to blow a hole in Europa's crust and catch the stuff that flies out (scientists refer to this as a "precision impactor"). But there are more sedate versions of alien life–hunting that might be just as informative. One includes gently depositing a probe on the moon's surface, then having it look in the ice for the signatures of life, called biomarkers. And then there's the ideal scenario: melting through the crust and looking for life in Europa's oceans using a submersible. That level of ambition is out of reach for this trip.

Then there's the more fundamental problem of what to actually look for in a sample: Organisms? Cells? Proteins? Europan organisms could use different chemistry than we expect from Earthly creatures, and life's signature might be written in invisible ink or in a language Earthlings can't read. In other words, scientists speculate, even if we flew through a plume and grabbed handfuls of Europan microbes, it's possible we might not even know it.