Next month, a NASA representative will  begin a five-and-a-half-year journey to the second best place in  our solar system to find life.

Why the second? Well, the first is Earth.

And we’re already pretty sure  there really is life here. This robotic representative  goes by the name Europa Clipper, which reveals its target: Jupiter’s moon, Europa. And while it won’t be landing there, its  equipment will help astronomers search for aliens swimming in an ocean that’s  larger than all of ours put together. [♪ INTRO] Science fiction writers have  been talking about Europa as a place to find  extraterrestrial life for decades.

Take Arthur C. Clarke’s book 2010, his sequel to  the legendary 2001: A Space Odyssey… Or the 2013 found-footage movie Europa Report, where if the moon’s deadly  environmental conditions don’t kill you, the giant tentacled sea creatures  that live there surely will. But that’s fiction.

Not reality. So what do we know about the real Europa? Well, it’s the smallest of  Jupiter’s four main moons, and it’s roughly the size of our moon.

But because it’s orbiting Jupiter, that  puts Europa over five times further from the Sun than we are. So its surface is way colder than you  ever see in places infamous for their chilly temperatures here, like Antarctica or Siberia. I’m talking negative 140 degrees  Celsius during the middle of the day!

But beneath Europa’s surface, things  get warmer thanks to tidal heating. Basically, big ol’ Jupiter keeps tugging on Europa as it spins and swings around  in its elliptical orbit. That causes all of Europa’s rock  and ice to stretch and squeeze, creating friction and therefore heat.

But is it enough heat to melt any of that ice? Well, over the decades, humans  have sent a bunch of missions to visit the Jovian system,  like two Voyager probes in 1979, Galileo in the 1990s, and Juno,  which is orbiting Jupiter right now. And from these missions, scientists  have gathered pretty solid evidence that Europa has a very not-solid subsurface ocean.

It’s sitting beneath a massive shell of ice  that’s probably 15 to 25 kilometers thick. But the evidence also suggests that  the ocean itself is even thicker, stretching another 60 to 150  kilometers into the moon’s insides. And that means Europa could have twice  as much water as all of Earth’s oceans, even though it’s way smaller than our planet!

But to build and sustain any  potential Europan sea critters, you don’t just need a decent  supply of liquid water. You also need chemical ingredients in that  water like nitrogen, phosphorus, magnesium… basically, the kinds of things  you get in a multivitamin. And lucky enough, Europa’s  ocean seems to have them!

It also might have hydrothermal vents  on the seafloor, which over on Earth are a place many scientists think some  of the first life may have evolved! Sidebar: there is one other  moon in our solar system that ticks a lot of the same  boxes: Saturn’s moon Enceladus. It’s a good bit smaller than  Europa, as is its subsurface ocean, but it has these cool geysers  where the water plumes can shoot up through cracks in the ice shell all the way  into space, making it easier to analyze.

In fact, the Cassini spacecraft got  to fly through one of those plumes to metaphorically taste that moon’s water. Scientists still aren’t positive  whether or not Europa has plumes. But either way, its huge warm  ocean full of the right elements makes it the hottest  astrobiological target, right now.

And scientists have spent decades  trying to get a space probe to Europa where the moon is the primary  target, and not a side quest. A dedicated Europa mission has been  floating around since the late 90s, but Europa Clipper only started  construction a few years ago, back in 2019. At one point, the mission proposal even included a separate lander that would,  well, land on the surface.

But clearly, someone rewatched  the movie adaptation of 2010 and remembered HAL 9000’s  warning that humanity should “attempt no landing there”,  and the lander got scrubbed. Or, you know, maybe there were budget cuts. So when Europa Clipper arrives in 2030,  it will have to fulfill its three goals from a distance: to measure how thick  the ice shell is, to check that the ocean the right chemicals for life, and to look  for signs of geologic activity, like plumes.

Basically, the science team wants a  comprehensive view of Europa’s “ecosystem”, so they can determine what, if  any, kinds of life could be there. To make that happen, the spacecraft  will stay in orbit of Jupiter, but loop around Europa about 50  times over the course of three years, using nine different scientific instruments  to probe what’s happening both on and inside this little ice ball. To keep its equipment warm and  toasty that far from the Sun, it’ll be wrapped in one of those shiny  blankets you get after running a marathon.

And to protect its computerized brains  from Jupiter’s intense radiation, it’s got a proverbial safe  made of an aluminum-zinc alloy whose walls are about one centimeter thick. With solar panels that stretch  as wide as a basketball court, and a total mass equivalent to a large  elephant, Europa Clipper is the biggest thing NASA has ever made to visit  another world in our solar system. NASA is expecting to launch  this big guy in October.

After the launch window opens on the  10th, they’ll have 21 days before Earth, Mars, and Jupiter move out of  alignment for the flight plan that they’ve picked. But don’t worry too much. If NASA misses this window,  they can try again next year.

If all goes according to plan,  Europa Clipper will swing by Mars this coming February to get a little speed boost. That will send it back towards Earth  for a second, final speed boost that’ll get it to Jupiter by April, 2030. Juno might not be there to greet it…that  mission is only scheduled to run until 2025… but Europa Clipper won’t be alone for long.

The European Space Agency’s Juice probe  is also on its way to Jupiter right now. But it’s taking a longer flight path,  so it won’t get there until 2031. Together, they’ll help us uncover the  secrets hiding beneath Europa’s icy shell.

And if neither finds aliens,   they can at least inspire the next  generation of science fiction stories. Now, whether you plan on throwing  a launch viewing party or not, we here at SciShow have got  a way for you to celebrate. We have a limited number of Europa Clipper  pins that are ready to ship right now, so you can have one in your hands…or on  whatever object you want to pin it to… in time for the October launch.

You can order yours now by heading  over to Complexly.store/SciShow. [♪ OUTRO]