What Saturn's most mysterious moon could teach us about the origins of life

NASA's Dragonfly -- a robotic rotorcraft-lander that's designed to hop across the surface of an extraterrestrial body -- is set to voyage deep into the solar system to explore Titan, Saturn's largest moon, in 2026. Planetary scientist Elizabeth "Zibi" Turtle shares how studying this mysterious moon that's thought to resemble the early Earth could bring us closer to understanding the habitability of other planets -- and the origin of life itself.

Picture a world
with a variety of landforms.

It has a dense atmosphere

within which winds
sweep across its surface

and rain falls.

It has mountains and plains,

rivers, lakes and seas,

sand dunes and some impact craters.

Sounds like Earth, right?

This is Titan.

In August 1981,

Voyager 2 captured this image
of Saturn's largest moon.

The Voyager missions have traveled
farther than ever before,

making the solar system and beyond

part of our geography.

But this image, this hazy moon

was a stark reminder
of just how much mystery remained.

We learned an exponential amount
as the Voyagers flew by it,

and yet we had no idea
what lay beneath this atmospheric blanket.

Was there an icy surface with landforms
like those of the other moons

that had been observed
at Saturn and Jupiter?

Or perhaps simply a vast
global ocean of liquid methane?

Shrouded by the obscuring haze,

Titan's surface was
a huge, outstanding mystery

that Cassini-Huygens,
an orbiter lander pair launched in 1997,

was designed to solve.

After arrival in 2004,

the early images Cassini sent back
of Titan's surface

only heightened the allure.

It took months for us to understand
what we were seeing on the surface,

to determine, for example,

that the dark stripes,

which were initially so unrecognizable
that we referred to them as cat scratches,

were actually dunes made of organic sand.

Over the course of the 13 years
Cassini spent studying Saturn

and its rings and moons,

we had the privilege

of going from knowing almost nothing
about the surface of Titan

to understanding its geology,

the role the atmosphere plays
in shaping its surface,

and even hints of what lies
deep beneath that surface.

Indeed, Titan is one
of several ocean worlds,

moons in the cold outer solar system

beyond the orbits of Mars
and the asteroid belt

with immense liquid water oceans
beneath their surfaces.

Titan's interior ocean may have
more than 10 times as much liquid water

as all of the Earth's rivers, lakes,
seas and oceans combined.

And at Titan, there are also
exotic lakes and seas

of liquid methane and ethane
on the surface.

Ocean worlds are some
of the most fascinating places

in the solar system,

and we have only
just begun to explore them.

This is Dragonfly.

At the Johns Hopkins
Applied Physics Laboratory,

we're building this mission
for NASA's new Frontiers program.

Scheduled to launch in 2026
and reach Titan in 2034,

Dragonfly is a rotorcraft lander,

similar in size to the Mars rovers
or about the size of a small car.

Titan's dense atmosphere,
combined with its low gravity,

make it a great place to fly,

and that's exactly
what Dragonfly is designed to do.

Technically an octocopter,

Dragonfly is a mobile laboratory
that can fly from place to place

taking all of its scientific
instruments with it.

Dragonfly will investigate Titan
in a truly unique way,

studying details
of its weather and geology,

and even picking up
samples from the surface

to learn what they're made of.

All told, Dragonfly will spend
about three years exploring Titan,

measuring its detailed chemistry,

observing the atmosphere
and how it interacts with the surface,

and even listening for earthquakes,

or technically titanquakes,
in Titan's crust.

The Dragonfly team,

hundreds of people across
North America and around the world,

is hard at work
on the design for this mission,

developing the rotorcraft,
its autonomous navigation system

and its instrumentation,

all of which will need to work together
to make science measurements

on the surface of Titan.

Dragonfly is the next step
in our exploration

of this fascinating natural laboratory.

In flying by, Voyager hinted
at the possibilities.

In orbiting Saturn for over a decade

and descending through Titan's atmosphere,

Cassini and Huygens pulled
Titan's veil back a bit further.

Dragonfly will live
in the Titan environment,

where, so far, our only close-up view

is this image the Huygens probe
took in January 2005.

In many ways, Titan is the closest
known analogue we have to the early Earth,

the Earth before life developed here.

From Cassini-Huygens' measurements,

we know that the ingredients for life,

at least life as we know it,

have existed on Titan,

and Dragonfly will be fully immersed
within this alien environment,

looking for compounds similar to those

that might have supported
the development of life here on Earth

and teaching us about
the habitability of other worlds.

Habitability is a fascinating concept.

What's necessary to make
an environment suitable to host life,

whether life as we know it here on Earth,

or perhaps exotic life that has developed
under very different conditions?

The possibility of life elsewhere

has inspired human imagination
and exploration throughout history.

On a grand scale,

it's why the ocean worlds
in the outer solar system

have become such
important targets for study.

It's the "what if"
that drives human exploration.

We don't know how chemistry
took the step to biology here on Earth,

but similar chemical processes
may have happened on Titan,

where organic molecules
have had the opportunity

to mix with liquid water at the surface.

Has organic synthesis progressed
under these conditions?

And if so, how far?

We don't know ... yet.

What we will learn from Dragonfly,
this fundamentally human endeavor,

is tantalizing.

It's a search for building blocks,
foundations, chemical steps

like those that ultimately
led to life on Earth.

We're not sure exactly
what we will find when we get to Titan,

but that's exactly why we're going.

In 1994, Carl Sagan wrote,

"On Titan, the molecules
that have been raining down

like manna from heaven
for the last four billion years

might still be there,

largely unaltered, deep-frozen,
awaiting the chemists from Earth."

We are those chemists.

Dragonfly is a search
for greater understanding,

not just of Titan and the mysteries
of our solar system,

but of our own origins.

Thank you.