[MUSIC PLAYING]
KEVIN HAND: Oceans exist beneath the ice shelves of moons
of the outer solar system.
If we've learned anything about how life on earth works,
its out where you find the liquid water,
you generally find life.
And so if Europa's inhabited, if Enceladus' inhabited
by microbes or some other creatures,
how do we actually go about detecting those life forms?
We can't wake up in the morning and go to Europa,
so instead we wake up in the morning and go to the lab.
My name is Kevin Hand.
I'm a scientist at NASA's Jet Propulsion Laboratory
in Pasadena, California.
In a way, what we're trying to do is sort of reverse engineer
what's happening on Europa's surface
and potentially figure out what kinds of chemical signatures
might be indicative of biology within Europa's ocean.
So Europa's got this liquid water ocean,
but it's covered by an ice shell that's
a few to maybe as much as 20 kilometers in thickness.
No sunlight is actually going to get down to that ocean.
Does that mean it's kind of game over for life?
No.
The bottom of our own ocean has ecosystems
powered by hydrothermal vents where the microbial communities
do just fine without any sun.
If we were able to drill through the ice on Europa
and drop a camera into its ocean and something
swam up to the camera, then touch down, you found life.
But it's going to be a while until we
do that, and so at least for the near-term exploration
of these worlds, we're going to be limited to measurements that
are made through spacecraft flying
by and through robotic vehicles that land on the surface
and then grab some material off the surface.
So what would we look for?
Much of what we do in our lab is recreate the surface of Europa
at many different scales.
At the tiniest scale, we've got these chambers
that we refer to as our Europa in a can.
These are vacuum chambers that allow us to pump down
to Europa temperatures, which is about
minus 280 degrees Fahrenheit.
We can bring it down to the space
vacuum of Europa's surface, and we can then irradiate it
with energetic electrons or ions, which
is what happens to ice on the surface of Europa.
We've put salts into the chamber,
because we think that Europa's ocean is salty.
We put it in and it's a nice, pure white.
We irradiate it under Europa upper conditions, take it out,
and it's a brownish yellowish color.
And some of that color sort of matches the discoloration
on Europa's surface.
We've also put difference carbon compounds in there,
and sometimes we can create a little waxy goo.
And that's interesting, because maybe these organic compounds
are not getting destroyed by the radiation,
but instead they might be synthesized
into larger compounds.
And then we've also put microbes in there
and irradiated microbes and looked
for the remnants of what would serve
as a sign of microbial life.
We've got these stockpot chambers
that are kind of a quick Macguyver-y version
to recreate Europa's surface.
And then some of our experiments feed forward
into the design of robotic landers and sampling systems.
Our team has built a vehicle that we call the Buoyant Rover
for Under Ice Exploration.
And basically what it does is it floats
on the underside of the ice and look
at the ice-water interface.
Those capabilities will hopefully someday
be used to explore these foreign distant oceans on worlds
like Europa and Enceladus.
You've got this incredibly cold ice on Europa's surface.
At that temperature, is it possible to even sample that
ice, or is it so hard that you just cannot drill into it.
And we've done experiments to get at exactly that question
and turns out, with the right tools,
we can put a saw blade down in and through that ice.
And then most recently, our team has created
what we call the Ark of Europa.
This is a very large vacuum chamber and cooling system.
And then there is roughly 30-centimeter thick block
of ice within there that is then subject to lights going back
and forth, kind of like the rise and fall of the sun on Europa's
surface.
And that may create spikes and dips within the ice surface.
This is where our Ark of Europa will help,
because we'll be able to recreate the surface
structure of Europa.
There's still another nearly 15 years or so
to go before we maybe land on the surface
and then sample the surface to look for signs of life,
but I predict that within our lifetimes,
we will potentially revolutionize our understanding
of life in the universe and our place in it,
and that's because we do have a pretty
robust plan for exploring our solar system and beyond.