NOVA

- [Instructor] JWST is also looking for the chemical building blocks of life much closer to home, in our cosmic backyard.

- One big question I want this telescope to answer is if there is life in our own solar system.

If we found it in our own solar system, it would really hit home that it's not so rare that life can happen.

- There are three places in our solar system beyond the Earth and beyond Mars, which are good candidates to go look for life, and those are Europa around Jupiter, and the moons of Saturn, Enceladus and Titan.

- Titan is a really exciting moon because it has an atmosphere, and rivers, and streams, and lakes, and oceans.

But instead of being made of water like they are on Earth, they're made of methane, like liquid methane.

So it has a water cycle like we have on Earth, but it's a methane cycle.

And that's really exciting for scientists because if we find life on Titan, it's not gonna be life like it is on Earth.

It's gonna be a totally different life.

So that's a really exciting thing to be looking for.

But also, how do you look for life that you don't understand?

So it's also a massive challenge.

- So the question comes up.

Can life evolve from chemistry in a liquid medium that's not water, that doesn't have the polar properties of water?

And the answer is we don't know.

- [Instructor] Researchers are also on the hunt for the ingredients for life as we know it on Enceladus, a moon of Saturn, and Europa, a moon of Jupiter.

- Those are what are called ocean worlds, which means that they have liquid water in their interiors.

- [Geronimo] Imagine that there's a big body of water below the surface protected from the environment.

- Where there could be this subsurface ocean, where there could be hydrothermal vents, just like the ones that we have on Earth, which have life like plants and animals.

- Full of organics, maybe some energy, internal energy, heat energy, and you have the soup of life.

We don't know what could be happening there, but it's definitely a place that has all the right conditions for us to explore.

- Some biochemists have suggested that it's in environments like this where life might have got going billions of years ago on the Earth.

- And that would be amazing to find.

Even if we just found bacteria, that would be amazing.

(pensive music) - [Instructor] Back in 2015, the Cassini mission studied Saturn, its rings, and moons, and captured this image of plumes bursting out of the ice at Enceladus's southern pole.

- We saw dozens of fine jets shooting off the south pole of Enceladus.

When these pictures hit the web, the web exploded.

- And so we see with Enceladus, there are places where the ocean actually escapes from the surface, and it just flows out of these cracks and bursts out in outer space.

- So this is, in effect, our best opportunity to study an extraterrestrial habitable zone.

- [Instructor] The same may be true for Jupiter's Moon Europa.

Covered with cracks and ridges that could be caused by the heat of an ocean beneath its icy surface.

- So we'll be looking for water signatures, so H2O, the same water that we have on Earth.

And we'll also be looking for things like methane, which can be a chemical tracer that gives us an inclination that there might be something alive.

Bacteria on Earth produces methane.

We probably won't directly image life because you can't really image bacteria from a telescope, but you can look at what the bacteria creates.

- [Instructor] When it comes to the search for the chemical building blocks of life in our own solar system, JWST's observations of Enceladus and Europa are finally in.

- I was wondering about this, by the way.

- [Instructor] And researchers have begun to analyze their data, pixel by pixel, creating these chemical maps of two mysterious worlds.

(pensive music) When it comes to the plumes of Enceladus, they see something downright bizarre.

- We saw this huge plume, which stands at 40 times the size of the moon.

- [Instructor] To put this in perspective, this red pixel is about the size of Enceladus.

- The moon is within a pixel.

The pixel is actually bigger than the moon.

- [Instructor] The blue pixels around it, water pouring out of the plumes.

- [Geronimo] This is gonna be right.

This is to be compared to the moon.

- [Instructor] And this massive plume may be chock-full of clues to the chemical building blocks of life in its underground ocean.

- We can look for carbon dioxide, carbon monoxide.

For every single pixel that we had, we actually had a full spectrum behind it.

- [Instructor] Europa also delivers a surprise.

It turns out that its surface is far more complex than the team expected.

- So this is on the surface.

- This is on the surface.

We're seeing all this surface composition speaking to us.

I mean, and we have a spectra for every single of these pixels, so we can actually see what is made of.

So I think this data's gonna be super cool.

We're seeing things on the surface I'd never seen before.

We can see the ice is changing, and new ices signatures that we were not expecting.

You just have to go and mine it and search for it.

If you don't search for it, you don't know.

So our exploration has been just slowly, going molecule by molecule, but there are hundreds of other molecules or ices that may be hidden below behind every pixel.

- [Instructor] Geronimo Villanueva and his team will spend the next few months pouring over those pixels, hunting for the chemical building blocks of life on Europa and Enceladus.