All right, there's ice on Mars,
which means there's lots of potential for evidence of past life on Mars.
So, there's plenty of data for NASA to keep testing.
But we shouldn't just look in one spot.
That's true. The solar system is a vast and wondrous place.
If Mars has potential, perhaps other spots do too.
Great work, everyone. All this talk of ice sure is making me thirsty.
So where should we look next?
Thanks, big brother.
Well, we all know life needs water.
So if we wanna find life, we should explore a place that has lots of water. So if we wanna find life, we should explore a place that has lots of water.
A place with lots of water sure sounds nice right about now.
And I have just the place: Europa.
It's pronounced "Europe."
No, sir. Europa is one of Jupiter's 79 moons.
And according to these images, it looks very promising.
It's covered in ice.
We already explored a planet with ice, and we didn't find any aliens.
Yes. But as we learned on Mars,
wherever there's ice, there could also be liquid water.
If we search Europa, who knows what we'll find.
Did you say Europa?
Wonderful choice.
NASA is very interested in Europa as a potential place to find life
because our probes suggest there might be an ocean there!
Could we use the probes to help us explore Europa?
Well, we'd need someone who's very skilled at operating robots.
Ladies and gentlemen, this is your captain speaking.
We'll be arriving at Europa shortly. So sit back and enjoy the flight.
Okay then. Happy hunting.
How's our search going? Any updates?
The good news is we found ice.
Lots and lots and lots of ice.
The bad news is no ocean.
I don't know why you're surprised.
The further away a planet is from the sun, the colder it is.
And the colder it is, the less likely you are to find liquid water. Just ice.
Let's keep searching.
CARA said they have evidence of an ocean. It's got to be here somewhere.
Well, we finished looking over the whole moon. Should we do another sweep?
Like I said, we are never going to find anything on this snowball. Just ice.
Wait. I think I found something.
Hey. I see it too.
Marcie, can you enhance the image?
On it, sir.
A geyser!
That's liquid water.
Do you know what this means? Do you know what this means?
The ocean we've been looking for isn't on the surface. It's underneath the ice.
Wow. An ocean inside a moon?
Just where I thought it would be. But Europa's so far from the sun.
Why isn't the water frozen?
I can answer that!
The gravitational pull from Jupiter's orbit is so strong,
it creates waves like ocean tides.
The energy from those waves keep Europa's water warm and liquid under its icy shell.
We're not sure yet,
but we also think that tidal energy might also produce hydrothermal vents! but we also think that tidal energy might also produce hydrothermal vents!
Hydrothermal events? That sounds fancy.
No, Sally, vents.
They're like geysers but on the ocean floor.
They release jets of warm water
that might be filled with organic molecules from the rocks below.
The exact minerals that form the building blocks of life.
So, Europa has water, energy and organic material.
And it's possible it might have another important component for life: time.
Having water, energy and organics is a good start,
but it takes a long time for life to grow and evolve.
We think Europa's ocean has existed for billions of years.
So, anything could be in there,
from single-celled organisms to giant sea creatures.
Perhaps it won't be much longer until we have the technology to find out.
Think of the possibilities. Like space sharks. Think of the possibilities. Like space sharks.
I'm not sure I'm ready to think about space sharks.
I'll go get a mop.
An ocean in a moon.
And another amazing clue in our search for life.
Why can't I have a normal dog?