Tech

This frigid world is our best hope of finding alien life

Kelly Dickerson

2016-01-07T23:52:00Z

Sending a spacecraft to a distant, frozen moon might sound like a waste of time.

But once you know that moon hides a vast subsurface ocean — what astronomers think is the most likely place we'll find life beyond Earth — you might wonder why it's taken us so long to get there.

That moon is called Europa, and NASA got the green light last summer to plan a mission to explore it.

And now, with NASA's 2016 budget got an unexpected $1.3 billion raise, it looks like a mission to Europa is closer to being a certainty. About $175 million of the 2016 budget is earmarked for Europa, with $25 million of that going toward developing a lander to touch down on its surface.

It will be at least a few years before a spacecraft and lander launches — they'll have to hitch a ride on a colossal rocket NASA hasn't built yet. Still, the space community is psyched.

Here's what makes Europa such an important place to explore, according to a video from NASA:

Europa, one of Jupiter's four largest moons, has been in NASA's sights for decades. It's entirely covered in a thick, icy shell.

Europa is unusual because it's not pockmarked with craters like most moons, including Earth's moon.

Instead, its surface is scarred with deep ridges and cracks that look like shattered glass.

This is probably because Europa doesn't follow a perfectly circular path around Jupiter. So when the moon draws close to Jupiter, it stretches into an oblong shape. And when it gets far away, it shrinks back into more of a sphere.

Scientists think Europa's surface distorts by 30 meters every 85 hours — the time it takes to orbit Jupiter. All that stretching probably gives Europa its cracked shell.

But scientists are most interested in what lies beneath the moon's surface: The stretching also heats up the moon's core, creating a global ocean below the frozen crust.

Europa's airless surface never rises above minus-260 degrees Fahrenheit, but the frosty shell helps insulate the ocean from space and keep the ocean liquid. And where there's liquid water, there might be life.

Source: Space.com

There's some pretty compelling evidence that this ocean exists. Parts of the surface are covered in what look like ice drifts. Ice chunks moving around the Arctic Ocean create a similar pattern on Earth.

There are also hummocks on Europa's surface that scientists think might be caused the freezing and melting of lakes within the frozen crust:

Europa's magnetic field is more evidence that a vast ocean exists. Scientists think the magnetic field is generated by tidal forces below the surface.

So it seems highly likely Europa is hiding a water world. And scientists are wondering if it's anything like our oceans on Earth.

We already know Jupiter's other moons spray nutrients all over Europa's surface. So if any sink down into the subsurface waters, then Europa's ocean may have the materials necessary to support life.

europa surface jupiter illustration nasa — Artist's concept of Europa's frozen surface. NASA/JPL-Caltech

Source: NASA360

Scientists think we might find the same kind of critters that we see around the deep-sea hydrothermal vents in Earth's oceans.

Source: Business Insider

That's why NASA is eager to send a probe to Europa.

It won't be an easy mission. Europa sits in the middle of Jupiter's giant belts of powerful radiation, so any spacecraft we send there has to be heavily shielded.

Source: EarthSky

Early plans suggest the mission might launch sometime in the 2020s, arrive at Europa a few years later, and then perform multiple flybys. We haven't seen any details on the lander yet.

You can watch the whole video from NASA here:

NASA Space