Secrets of the Universe (2022–…): Season 1, Episode 6 - Finding Life on Mars - full transcript
Secrets of the Universe -
Finding Life on Mars
In the last 50 years of exploring Mars,
we've gone from thinking maybe there were canals and aliens
that had created this whole ecosystem,
transporting water from the polar caps
toward gigantic farms,
to getting there and seeing these pictures
of just cratered landscapes,
a surface that's baked in radiation,
barely an atmosphere to speak of,
not a place that could sustain life as we know it.
We look at the planet Mars and its this rusty red ball
and it doesn't look like it's a great place
for life to live at all.
You know, stagnant.
When I was a kid, Mars looked
incredibly dead and it was boring.
The end, close the book don't ever go back.
I think when the general public thinks of Mars,
they imagine this dead red rock
where we haven't found any evidence of life.
So why do we keep exploring?
Why do we keep sending these missions there?
It seems Mars has failed to live up
to our dreams of finding life beyond Earth.
But is that about to change?
With NASA's perseverance Rover mission,
we may finally find out if Mars
once hosted organisms on its surface.
Perseverance, it is an entirely
unfamiliar kind of mission.
We've never done anything like this before.
This feels like a revolution right now
in our understanding of Mars.
Whether Mars had life is the question.
If it did start there, maybe life is really easy.
If it didn't start there maybe is really hard.
Touchdown confirmed.
Perseverance safely on the surface of Mars,
ready to begin seeking the signs of past life.
Touchdown confirm we're gonna wait for the images.
The second we landed,
then we actually started getting to work
as the images started coming down.
Perseverance is continuing to transmit.
Yes!
Are we alone in the universe?
And that's what we're trying to figure out.
That's what exploration's all about.
In 2012, Perseverance's predecessor,
Curiosity Rover, begins its mission
to establish if Mars ever had an environment
that could support life as we know it,
the essential first step towards seeking life itself.
When Curiosity is driving around,
it's driving over rocks that are billions of years old.
Now Curiosity is not designed
to actually look for signs of life,
but it most certainly can identify an environment
that has everything that's necessary for life to be there.
I'm interested in knowing if there are organic molecules
in the rocks that we encounter.
Curiosity is the first Rover
with a miniature laboratory on board
capable of detecting organic molecules.
Organic material is critical for life as we know it.
So if we don't find any on Mars, that's a huge deal.
Mars is just
so inhospitable.
The surface is being bombarded by ionizing radiation,
which is not good for life or organic molecules.
Not good.
It tends to break them down.
Every sample was a bit of a risk scientifically
'cause we didn't know what we were gonna come across.
I mean there were samples where we
really didn't learn much of anything.
If we had the conditions for life to survive,
we would expect to find organic material.
We still hadn't seen any with Curiosity
and this was a big mystery.
Was there never any organic material on ours?
Our best hope was to just keep looking.
We came across a bunch of cobbles
and stones that were all rounded.
The best way of doing that is in a river.
We realized there had been water flowing
on the surface of Mars in the past.
Then we knew we were on the right track.
We were heading to where we thought the lake was.
We saw these features and they sort of indicated
that there was shallow water.
Shallow water is a great place for life to do its thing,
get immediately trapped into the sediments.
So I was particularly interested in that sample.
And when we drilled into the first rock,
the sediment was dark gray.
It hadn't been rusted like everything else
that you see on the surface of Mars.
And there was a window into the past.
There was organic matter in that rock
and that it had survived eons
of ionizing radiation at the surface of Mars.
The discovery of organics
is a huge step forward in establishing
the habitability of Mars.
But falls short of proving life ever existed there.
Finding organics is not proof of life on Mars at all.
It's a nice hint, but we don't know
whether these organic molecules actually rained down
on the surface of Mars in the form of meteorites over time.
Okay, great.
We finally have found organics on Mars,
but it doesn't tell us anything about
where those molecules came from
and what they're doing there and what they mean to us.
Because of missions like Curiosity,
we know that Mars was absolutely habitable.
So the next question is was it ever inhabited?
Back on Earth,
a radical new mission is being prepared.
The goal of the Perseverance Rover
is to look for signs of ancient life on Mars.
We finally put together the pieces
of what Mars used to to be like
and we know what evidence we need to definitively say
whether there was or wasn't life on Mars.
So Perseverance's goal is to take us to that next step.
The purpose of Perseverance Rover mission
is to find some ancient traces of life from us.
And, for that purpose, the instruments need
to be different from the Curiosity Rover.
And we need to have more techniques to meet this requirement
and that's a price to pay to be on board.
But how do you begin to unravel
the clues that point to life?
On the end of Perseverance's robotic arm
is an instrument called SHERLOC,
designed to take Curiosity's investigations
into organic molecules to the next level.
Curiosity has a mass spectrometer
and that's one way of detecting for organic molecules.
What we do is something a little different.
We are looking for spectral signatures.
We shine a laser on a surface,
and then we look at the back scattered light coming back
and how that light changes tells us what's in the surface.
They detect and classify organic molecules
on a very fine scale.
The astrobiologists are going crazy for this instrument
because the wavelength at which the spectrometer operates
is optimized for organics.
On the opposite side
of the robotic arm from SHERLOC,
is an instrument called PIXL,
a radical reimagining of a geologist's most basic tool.
I sometimes refer to it as a chemical hand lens.
You know, the hand lens being the eye piece
a geologist uses to look at the rock.
Imagine being able to look through that and see,
not just what the rock looks like,
but also what it's made of.
PIXL uses spectroscopy to create
a chemical map of the surface,
to reveal how life might have affected the rock.
In a way it looks like a camera image,
but it is really the fingerprints of the rock.
And in turn those fingerprints tell you
the history of the rock.
How it was formed, what environment it was in.
The PIXL instrument was something that arrived
from doing field geology out in Western Australia one year.
Trying to look for evidence of life
in the oldest rocks on Earth.
I found that trying to figure out on Earth
whether something that was in a rock
that was possibly biological was actually biological
was really helped by this instrument
called an x-ray microscope.
It's like a huge...
A pretty decent sized beach ball.
It's connected to the mains power.
And, of course, if anything goes wrong with it,
then you get a crew come out to fix it.
The most challenging aspect of building PIXL
is the not being able to break.
You have to be able to get off the surface of Earth,
to Mars, land on the surface of Mars
and then survive on Mars for the entire prime mission
and hopefully well beyond.
All of that had to be done
in addition to getting it down from 80 centimeters cubed
to about 20 centimeters cubed.
There were certainly moments where it was like,
my God, how complicated is this becoming?
Tailoring these precision instruments
for a future on Mars is a daunting engineering challenge.
Even for those who have been there before.
To develop an instrument for Mars is pretty easy.
You just have to worry about every single thing
down to the bolts and where the bolts go
and where the bolts don't go.
Most instruments that are SHERLOC-like
do not like vibration.
And we're attached to a drill that vibrates.
The temperature swings on Mars every day
is a hundred degrees Celsius.
Electronics really don't like to be hot, then cold,
then hot, then cold, then hot, then cold every single day.
And the brutality of the Martian atmosphere
is matched by the trauma of the space flight
that will get them there.
We do testing informally known as shake and bake, right?
Because you wanna shake it
and you wanna heat it.
Everything that goes into space
has to be really thoroughly tested.
You could almost say violently tested.
We vibrate it at different frequencies
and make sure no screws come loose,
nothing falls apart.
When I saw the shaking, I was like, my God,
what about the optical alignment?
It's a bit heartbreaking to see your instruments
suffering like that.
The jewel in the crown
of Perseverance's instruments is the eye catching SuperCam.
SuperCam is often described as the head of the Rover.
And it is, it's sort of this cyclops laser eye.
SuperCam's long range, rock busting laser
could make all the difference in the search for life.
We can shoot the laser at a rock
up to seven meters away from the Rover.
So we can actually analyze things
all around us without having to drive up to it.
The rock gets literally zapped
and the atoms come screaming off
at 10,000 degrees in a plasma
and then, with that cyclops eye,
we collect some of that light.
We can tell what are the chemical elements
that are present in that rock?
It blows my mind that a scientist in a lab one day
thought let's blow up rocks with lasers
and see what they're made out of
and now we're doing this on Mars.
Just below SuperCam
are two stereoscopic cameras,
the key to navigating Martian terrain,
with the driver using special 3D glasses.
So, as a Rover driver, I'll put on my 3D goggles
and getting the three dimensional data
allows you to really visualize the terrain
in order to determine if something's a hazard.
And on Perseverance, the cameras are fantastic,
very high resolution, so we'll be able to see a lot further.
The complex optics for SuperCam
and the entire head of Perseverance
are made in Toulouse by the French space agency CNES.
At the end of 2018, the launch is in sight.
But the future of NASA's cyclops eye
is about to be thrown into doubt.
We had a phone call every Tuesday with JPL.
We had a small modification to do on the instrument,
just be for delivery.
We were actually on the phone talking about
final touches that they were doing
on this beautiful masterpiece.
And it happened during this phone call,
my test team in Toulouse called me saying
we have a big problem.
The last stage of the modification to SuperCam
is to heat treat the glue used during final assembly.
To make sure that the bonding is done correctly,
we put the instrument into a small oven
and we bake it at 50 degrees Celsius.
That's what we did.
But we had an issue with the hardware, the thermal chamber.
The thermal couple in that furnace broke,
went to its maximum temperature.
It was a disaster.
Basically, we destroyed
all the optical parts of the mast unit.
Two months before they'd agreed to GPL.
I was still on the phone call with GPL.
We started to realize that the people
on the phone in France were very distracted,
said, this thing is destroyed.
And we had just a few months to go.
If something breaks on your flight model,
that could actually end your mission.
Part of the problem is the launch window for Mars
opens up every 26 months.
If we miss this launch opportunity,
we gotta wait 26 more months.
Probably Mars 2020
will launch without us.
But that's where we are, now what can we do?
SuperCam is a write off.
The team's only hope of hitting the launch deadline
is to somehow repurpose existing hardware.
And they have one chance to pull this back.
In parallel to building the SuperCam flight unit,
we were also building a laboratory unit almost identical
so we could do experiments on Earth during the mission.
We had to take that laboratory unit
and try to make it flight worthy.
But we had to constrain everything in six months
instead of one year taken to build the first model.
It is really a last ditch effort.
It was like, we've gotten this far
and then we're not gonna make it.
We had to work days and nights the weekend and everything.
But in six months we had a new SuperCam mast unit.
Honestly, I'm so happy to see
the performance of the instruments,
it's really a perfect instrument.
As Perseverance
is packed and prepared for launch,
the mission is entering is most uncertain phase,
where history has lessons for those
choosing to visit other worlds.
Getting to Mars is no easy task.
You have two moving targets, Earth and Mars,
and then you're throwing in the third moving target
of the thing you're trying to get
from one planet to the next
at thousands of miles an hour.
Schiaparelli was a technology demonstration,
a tiny lander that was Europe's first attempt
to land on the surface of Mars.
Everything had been going right
up to the point of parachute deploy.
Supersonic parachute inflation, that's a very violent event.
Was swinging too fast underneath the parachute.
Couldn't figure out which way it was up.
Unfortunately for Schiaparelli,
was like stealing defeat from the jaws of victory.
Schiaparelli ended up smashing into the surface of Mars
and left a nice little splot in the dust
that we could see from orbit.
Schiaparelli hit the ground going much faster
than it was designed to do.
And we call that creating a new crater on Mars.
And we felt, you know, really horrible for them
'cause you know, there's years of work that went into that.
You know, it was a terrible feeling.
It was just like another crash on Mars and we could be next.
The team on Perseverance looked at Schiaparelli
as very much a reminder of just how hard this really is.
Ten, nine, eight,
seven, six, five,
four, three,
two, one.
The 58 meter tall Atlas Rocket
is only just powerful enough to deliver
the one metric ton Rover to Mars at its closest approach.
Even so, the journey will take seven months.
Yeah!
Woo.
In the meantime,
investigators turn their attention to the landing site
that they believe offers the best opportunity
for finding ancient life.
Jezero crater is tucked along the western edge
of one of the largest basins in the northern hemisphere.
If there was ever life on Mars,
then a place like Jezero is gonna be spot on.
Absolutely perfect to preserve evidence of life.
Jezero has long been on the list
of top possible landing sites
because it looks like there was a long lasting lake,
a body of water.
But the problem is that incredible topography
is also incredibly dangerous for spacecraft.
If you look at Jezero, there's just so many hazards,
there's a delta with really steep cliff walls.
Scientists want to go to places
that have a lot of topography, that have a lot of rocks.
But, as a guy who's trying to land Rover safely there,
when you look at all those things, you just see danger.
Perseverance has a new technology called
Terrain Relative Navigation that recognizes
hazards on the ground and takes avoiding action.
Terrain Relative Navigation
means that Perseverance can tell
whether there's a mound or there's a hill
or there's some other thing
that the Rover could possibly land on that would be bad
and it steers the Rover away from that.
And that's the only reason we could land in Jezero crater.
Without this navigation system,
you should expect that about 20% of the time,
you're not gonna make it.
Although the new technology
has been tested extensively on Earth,
this will be its first time operating in concert
with the entire landing system.
It's humbling right?
To realize that the first time you get a chance
to use your whole system is going to be
when it has to work at Mars.
On February 18th, 2021,
Perseverance is poised to enter the Martian atmosphere.
Now, 293 million miles from Earth,
the delay in communication
means the spacecraft must act autonomously
during the seven minutes it will take to land.
That's seven minutes from when you hit
the top of the atmosphere, going 12,000 miles an hour,
until we touch down,
there's literally nothing we can do.
We're just finding out what has already happened
about 11 and a half minutes ago.
We have spent more than six years
developing the instrument and you know that,
in seven minutes, everything can change.
Either you have the Rover on Mars
or you lose everything in seven minutes.
Perseverance is on her own.
But sends status updates back to Earth
in the form of a tonal code, similar to musical notes.
So it's kind of like it's singing
a little song to us on the way down
and each of those notes means something different.
You know, if you hit this note,
that means we deploy the parachute
or if you hit this other note,
it means something has really gone bad with something.
You wait for that telemetry
to come back and see what it tells you.
And if you're not getting the readings that you expect,
your heart just sinks into the pit of your stomach.
10 minutes before we get to the top of the atmosphere,
she tells us that something's gone wrong
with one of the electronics boxes, one of the computers.
All stations at this point,
let's limit our traffic on the net to critical issues only.
If Perseverance was right,
that something was wrong with that box,
we would lose the ability to fire thrusters
and the propulsion system not working
would be certain death.
Perseverance is actually being
pulled in by gravity and accelerating.
The mission would be over, no question.
There's a lot of silence in the room.
Everybody's monitoring that telemetry so carefully
knowing that we'd done everything we could.
And yet this
belief that it'll recover
and we continue to have a mission.
A vehicle slams into the atmosphere
going at about 5.4 kilometers per second.
On the outside of the vehicle,
we're getting white hot like the sun.
All we can do is take a look at what
Perseverance is telling us and worry.
Are your engines really gonna work
or are we about to fall to our death?
Luckily the spacecraft began to do things
that were consitent with the box working
because all of our thrusters seemed to be working fine.
So crisis averted for the moment.
But it definitely got our hearts beating.
The navigation has confirmed
that the parachute has deployed
and we are seeing significant deceleration.
We had cameras all over the place,
looking up at the parachute.
This was extraordinary.
This was a documentary.
Our current velocity
is 480 meters per second
at an altitude of about 12 kilometers
from the surface of Mars.
We're approaching at the mercy of the winds
and at the whims of the rockets.
If we happen to land on a too large a rock,
the mission is over.
Heat shields up.
Perseverance is now slowed to subsonic.
Our new system called Terrain Relative Navigation
allows Perseverance on her own to figure out
exactly where she is by taking pictures of the ground
and matching them up with an onboard map.
We light up rocket engines on that jet pack to slow us down
and steer us to the nearest safe spot that we can find.
Current velocity is at 75 meters per second,
at an altitude of about a kilometer.
But right after that, you can hear
one of my teammates call out tier end safety level problems.
Tier end safety bravo.
What that was telling us was that
Terrain Relative Navigation has done its job.
But the best place that it could land
was not the best case scenario.
It could no longer go to where we had originally targeted.
That causes us to freak out again.
Suddenly you're thinking, my chances
just dropped to one in 20
that we're gonna die at touchdown.
Perseverance flew about 600 meters to the southeast region.
If one thing goes wrong, its game over.
Skycrane maneuver has started.
20 meters above the ground,
we deploy the Rover and its wheels
below that power jump pack.
You have so much riding on this, like whether,
as a Rover driver, you are actually going to have a job
all depends on this landing.
It's nerve wracking the whole time,
all of those little black things
that were coming by the camera, I called those projectiles
that might have hit my instrument.
That's the fear.
We had our fingers crossed all the way through touchdown
that we had found a safe spot.
That skycrane let the Rover touch the ground
and then cut the cables and fly away.
Touchdown confirmed.
Perseverance safely on the surface of Mars.
People are jumping up and down elated.
So, to some people, landing looked perfect.
But I mostly just felt a massive sense of relief.
As soon as they gave us a coordinate,
we were able to load where the Rover is.
You're like, what is Jezero like?
You're curious about seeing the terrain.
You put on the 3D goggles
and it really transports you as if you are on Mars,
standing there from the perspective of the Rover's cameras.
It's very immersive.
Jezero was really spectacular
from the first image that came down.
I think I did that for hours.
Once we landed, the first thing I said
to my engineering team was, God, now it has to work.
So our stress like started increasing.
The investigators run calibration checks
on the instruments to see if they've survived the landing
and test the lasers on nearby rocks.
We went for a target
just a few feet in front of the Rover.
Made a nice target because we couldn't miss.
We were crossing our fingers,
praying that everything's gonna work.
When we saw the atomic emission spectra,
that was the moment of truth.
The spectra revealed
that the test rock is a basalt
common in ocean basins on Earth and across Mars.
The result confirms their hunch
that this was once an ancient lake.
But there's nothing to suggest life
ever existed here in the landing zone.
However, Perseverance is just a few kilometers
from the spectacular features
that brought it to Jezero crater.
So we landed right in front of a river delta
and what we're going to do is drive up this river delta and,
along the way, we're gonna take samples
and do scientific analysis on the rocks.
A delta forms when you have a river
that empties into some kind of standing body of water
and all of the material that was being transported
by that river stops moving
and sinks to the bottom and forms these layers.
Our experience from previous missions
is that this fine grain material is good
for finding clay minerals,
which might then contain organic molecules.
You can think about water being trapped in little ponds
and puddles around the place.
That's the kind of complexity that can eventually tell you
will lead to a discovery of life.
The delta has been dry
for probably three and a half billion years
but how would it have looked when water still flowed?
I imagine if I was sitting on the edge of Jezero crater,
just looking out over the lake,
when it was there four billion years ago,
you would have this very peaceful environment.
You might hear the sound of the river coming into the lake
on the side where the delta is.
It would probably just be this beautiful place.
I would love to think that maybe there were
some kind of fish or algae living in there.
I would love to see us discover a fossil
of some kind of plant, even if it's really unlikely.
You never know.
I wouldn't count it out.
We know that Mars was once a very different planet,
but there has been a lot of changes happened on Mars
since Jezero crater was formed
and since that huge fresh water lake was deposited.
Mars today is drier than the driest places on Earth.
In addition, the very extreme incoming radiation
would be an incredibly harsh environment,
even for the most hardy microbes on Earth.
But how did Mars become so hostile to life?
The answer will give clues
about where traces might still exist.
And investigators have focused on a critical period
when Mars had a molten planetary core like Earth does today.
Inside Earth, we have a molten core
and that spins around and generates
outside of the planet, the magnetic field,
and that magnetic field protects our planet
from the blast of ionizing solar wind coming off of our sun.
Protects us, protects the whole biosphere.
Now on Mars, it had that molten center
just like Earth does today.
But something happened on Mars
where that started to solidify around 3.9 billion years ago.
All of a sudden, the magnetic field stopped
and the solar wind blasted the atmosphere away.
It literally blows it away.
The moment the magnetic field was gone,
ionizing radiation had a huge impact on the surface.
And, forever more,
Mars was a completely unique, different place.
Perseverance Rover has a top speed
of just 0.1 miles per hour
and the journey to the delta is expected to take two years.
But before the search for life can begin,
Perseverance drives to a nearby flat expanse of regolith
where it will drop off a passenger.
Perseverance didn't go to Mars alone.
It took with it this tiny little drone called Ingenuity.
Underneath the belly, Ingenuity is sitting sideways,
the legs swing down, and then we drop to the surface
and from that moment on, there's no way
to come back to the Rover and reattach the umbilical.
Our mission had begun.
This 1.8 kilogram experimental helicopter
could prove invaluable as an aerial scout
in the search for life.
If it works.
There's a lot of challenges when it comes
to flying an aircraft on Mars.
One, the atmosphere is very thin.
It's one percent that of Earth's atmosphere,
there's almost nothing to generate lift with.
Back in 2014, the first prototypes
struggled to deal with the simulated Martian atmosphere
created in JPL's laboratory.
So how will it cope on Mars?
It's as if you operated it on Earth
at a hundred thousand feet, at 20 miles, high
and tried to fly.
Ingenuity was a total mystery to us.
Was it gonna work?
It doesn't carry any science payload.
The one and only purpose of Ingenuity
is to prove that we can fly on Mars.
And Martian weather is the wild card
that could make or break Ingenuity.
Mars can be a gusty place.
And so we were not sure how that turbulence
might affect this helicopter.
And perhaps the biggest threat to Ingenuity
is from Martian tornadoes.
We did see some pictures of Ingenuity
with a dust devil in the background.
Dust devils could probably do a number on that helicopter.
So today's the day of our first flight
on the surface of Mars.
We have sent the commands up the day before
and everyone's holding their breath.
Definitely very nerve wracking.
Equations tell you that you can get lift
if you make it light enough,
if you make the propellers big enough,
but can you control the flight?
That's another story.
Even taking off would've been a massive success.
The sheer power of the rotor system
to fight itself off the surface and produce lift.
It was awe inspiring.
The plan for the first flight is take off, hover,
come back down and land.
That's it.
Yeah!
Woo!
It came down on its feet, not on its side.
And so we were really applauding.
This is a big relief.
We did it, our mission is successful.
We have proven we can fly on Mars.
Ingenuity is now off scouting for the Rover.
One of my absolute favorite ideas
is to descend through a skylight hole,
into a lava tube cave on Mars.
That was never thought to be feasible
before this Ingenuity mission.
The fact that we flew this helicopter,
this drone helicopter on Mars
was really awesome for all of us.
NASA's faith in Ingenuity
has given them an eye in the Martian sky.
Now the search for signs of ancient life can begin.
But what exactly should Perseverance be looking out for?
Scientists have been trying to define what life is
for decades and they still are talking about it.
So there is no one clear definition.
The problem with looking for life is
there's a lot of problems with it.
The definition of life, it always uses the phrase alive
somewhere in the definition of it,
which is kind of circular and it doesn't make any sense.
Looking for life on Mars,
we have to make certain key assumptions.
It would be really hard to recognize a form of life
we've never imagined or encountered before.
So we start looking for something familiar.
But the problem is that, even here on Earth,
where we have plenty of life to study,
it's really hard to actually tell the difference
between chemistry, complex chemistry and life.
My idea of life is organisms
actually change the environment, they do things.
It's not like they deliberately think about doing this
but life chooses certain things that it wants.
So when we go look for life,
I look for indications of something very specific
that wouldn't be there if it weren't for life
needing that specific thing.
One thing that the investigators can agree on
is that the clues that point to possible
ancient life are called biosignatures.
Biosignatures are things that are left behind by life.
So the thing that was alive to have produced
whatever you're looking at isn't necessarily there anymore,
but you can tell it was there based on traces that it left.
We're trying to find potential biosignatures.
So we wanna look for places that, at one point,
had what we think life needs.
So we're looking for hydrothermal material,
minerals that could only be created
in the hydrothermal vents.
We're looking for carbonates, we're looking for things
that we know on Earth biology likes.
If we found something that looked like a hydrothermal vent,
we would stop and look at it for months I would hope.
Hydrothermal vents
that result from volcanic activity
are associated with life processes on Earth.
But Perseverance is also looking out
for bulbous rock structures called stromatolites,
a feature of Earth's most ancient landscapes.
So stromatolites are great because they're macroscopic
and I think they're like the tip of the iceberg
that alerts you to, hey, you know, look here.
They're really rock formations but they have within them,
organic carbon mixed with the rock layers
that were the sediments.
Life on the Earth tends to clump
and on Mars, we would expect the same thing.
Lakes lay down layers, they lay them down flat.
It's hard to imagine without biology how those things grow.
So life can alter the appearance of rocks.
A biosignature carved into the landscape.
But, on Earth, microbes can also affect
the abundance of certain minerals and rocks.
Could the same be true on Mars?
When you think about the things
that life needs to survive, you probably think of water,
maybe plants living off sunlight,
but there are actually microbes
that can live off of eating rocks.
If you ask a different scientist,
you'll get a different answer.
But my particular biosignature of interest
is a family of minerals that are high
in the element manganese.
Here on Earth, microbes absolutely love manganese
because it has a lot of really critical chemical properties
that they can use to actually do their metabolism.
Microorganisms have this amazing ability to adapt.
They are capable of getting energy in so many unique ways,
give them a rock and they'll figure out how to use it.
On Earth, high concentrations
of manganese oxide have been linked
to the presence of ancient microbial life
and a similar over abundance of this mineral
has already been found on Mars by earlier missions.
These minerals tend to form little bumps and crusts.
You'll just roll up to a new spot
and suddenly there is manganese.
And now Perseverance
is discovering signs of more deposits.
As we look through SuperCam data, we can see that
there is manganese in these rocks in Jezero crater.
It literally is the very first time we shot a rock,
you could see manganese in it.
You know, this is very intriguing.
It's not proof that life did this on Mars,
but we can start looking for other things
that can start building that case
that maybe life made these materials.
Perseverance's instruments are designed
to recognize the subtle imprint of microbial life
and the familiar chemistry of organic molecules.
But the devastating effects of ionizing radiation
add another level of complexity to the challenge
of locating biosignatures.
We joke about the fact that it's planet bleach.
Life as we know it needs water, an energy source
and organic carbon.
But Mars is a very bad environment
for a lot of organic molecules.
If there was life there, would that site
have preserved the evidence in a way
that we can find it today?
The challenges facing the robotic search
for life on Mars may appear overwhelming,
but Perseverance has come prepared
to tip the odds in its favor.
If we're going to find evidence of life on Mars,
we may get an incredibly lucky and do it on Mars,
but far, far more likely it's going to be in a laboratory
with proper equipment back on Earth.
And so Perseverance is an entirely
unfamiliar kind of mission.
Yes, we're driving around, we're looking at rocks,
we're doing science on rocks,
but it's being done to select samples,
take small drill cores from those samples,
put them in hermetically sealed containers
and leave them behind for a future mission
that is only now being planned.
An international mission to retrieve
and bring back to Earth, hopefully within the next decade.
The sample's about the size of your index finger.
And then you go and you unleash
all the power of laboratories on Earth
and try and look at even smaller scale.
This is really important because we can
actually take those samples
and look for signs of DNA in them.
And DNA is irrefutable proof of life.
We can tell you that it was not something
that came from Earth, it was something
completely native to the Red Planet.
Perseverance's instruments work together
to identify potential samples for return.
But trying to operate completely new hardware on Mars
is proving to be an ongoing challenge.
The stress never gets any less.
We're turning ourselves on today
and we're gonna do some spectroscopy on the surface.
I'm petrified that it's not gonna work.
I used to have an old car and every time I would go out
and turn the old car on, it's the same feeling.
Is this the time the car is not gonna start?
Mars is living up to its reputation
as an unforgiving host for even the night itself
is just another hazard to contend with.
What happens is, as soon as the sun goes down,
the temperature plummets,
the metal that the Rover's made of starts to contract
and the arm starts to move and drift down,
and that drift was actually not at all trivial.
PIXL needs 17 hours to create its detailed
microscopic maps of rock surfaces
and the sample must remain motionless
under the sensor for the whole period,
which created a headache for engineers
during the development of PIXL.
So we actually had to invent a new thing called a hexapod.
Like a six legged device,
legs that would sort of get longer and shorter to make sure
that you can stay the right distance from the rock
and actually stay over the right part of the right.
The ingenious engineering is put to the test
seven months into the mission
when the team must decide on
where to drill for a sample core.
The first stage is to grind the clean surface
so the rock can be tested.
It's really cool because you see a rock
that's completely different than the rock
you see on the outer surface.
It's pristine, it's not weathered, it's not dusty.
You can see individual crystals.
They're not tiny, they're actually really big.
It looks like it's a volcanic rock.
But there are some other smaller features
that are a little bit harder to resolve.
You have to go for a closer look.
When PIXL scans the surface,
four billion years of history is exposed.
PIXL can make us an incredible map
of the chemistry of this area.
We can see that these smaller features appear to be salts.
Crucially, the presence of salts
means the rock has spent time underwater.
But what nobody is expecting
is the presence of calcium phosphate.
What's so interesting about calcium phosphates
is that they form in some
very unusual environments on Earth
and, in general, they're very closely associated with life.
Phosphates have never before been discovered on Mars.
And so that makes them incredibly intriguing
to discover in Jezero crater.
The team decides to drill for a rock core
to return to Earth.
This sample could rewrite Mars history
and some believe that the salt could even contain
a microscopic hoard of lake water.
These types of salty materials in rocks
can preserve traces, little bubbles of water,
from when there was more water,
when these materials were being in placed in the rock.
And so these little bubbles of water
can preserve organic materials
so it's worth a look in these Martian samples.
The rock sample is stored,
ready to be dropped off.
The first of more than 30 tubes
destined for Earth laboratories.
The next step in solving a mystery
that began perhaps four billion years ago.
All of a sudden, Mars goes through
this incredibly dramatic change.
Something on a planetary scale
that we haven't experienced on Earth.
Did life survive, if it had been there?
Life does things with its environment.
We're looking for signs that organisms
are actually influencing what's around them
in a way that their natural environment
wouldn't do so on its own.
The whole biosphere has affected the planet,
have affected the mineral formation, every thing,
and that has got to be recorded in the rock
in some way, shape or form.
I think.
There should be something that we can decode from that.
It might take decades.
Mars is a entire planet you know?
A planet like Earth, full of diversity,
of all kinds of things we can't imagine.
So in a way, what I expect is the unexpected.
I'd like to know why Mars didn't have life
or why Mars did have life.
We're an exploration species and we want to know
where we fit in the universe.
Either answer is wonderful.
Are we alone?
Is there life out there or is life so special
that it's only here on Earth?
We might find evidence of that randomness
that defines the non-biological world.
If there is evidence of life having once existed on Mars,
then that tells us that life can exist on a planet
and then it can disappear.
That's pretty...
That's the reason why we're doing this.
You can't rely on your planet to always provide you a home.
Every time we look at Mars in a different way,
we discover something grand.
But do I think that the samples
have evidence of life in them?
Depends on what day you ask me.
Finding Life on Mars
In the last 50 years of exploring Mars,
we've gone from thinking maybe there were canals and aliens
that had created this whole ecosystem,
transporting water from the polar caps
toward gigantic farms,
to getting there and seeing these pictures
of just cratered landscapes,
a surface that's baked in radiation,
barely an atmosphere to speak of,
not a place that could sustain life as we know it.
We look at the planet Mars and its this rusty red ball
and it doesn't look like it's a great place
for life to live at all.
You know, stagnant.
When I was a kid, Mars looked
incredibly dead and it was boring.
The end, close the book don't ever go back.
I think when the general public thinks of Mars,
they imagine this dead red rock
where we haven't found any evidence of life.
So why do we keep exploring?
Why do we keep sending these missions there?
It seems Mars has failed to live up
to our dreams of finding life beyond Earth.
But is that about to change?
With NASA's perseverance Rover mission,
we may finally find out if Mars
once hosted organisms on its surface.
Perseverance, it is an entirely
unfamiliar kind of mission.
We've never done anything like this before.
This feels like a revolution right now
in our understanding of Mars.
Whether Mars had life is the question.
If it did start there, maybe life is really easy.
If it didn't start there maybe is really hard.
Touchdown confirmed.
Perseverance safely on the surface of Mars,
ready to begin seeking the signs of past life.
Touchdown confirm we're gonna wait for the images.
The second we landed,
then we actually started getting to work
as the images started coming down.
Perseverance is continuing to transmit.
Yes!
Are we alone in the universe?
And that's what we're trying to figure out.
That's what exploration's all about.
In 2012, Perseverance's predecessor,
Curiosity Rover, begins its mission
to establish if Mars ever had an environment
that could support life as we know it,
the essential first step towards seeking life itself.
When Curiosity is driving around,
it's driving over rocks that are billions of years old.
Now Curiosity is not designed
to actually look for signs of life,
but it most certainly can identify an environment
that has everything that's necessary for life to be there.
I'm interested in knowing if there are organic molecules
in the rocks that we encounter.
Curiosity is the first Rover
with a miniature laboratory on board
capable of detecting organic molecules.
Organic material is critical for life as we know it.
So if we don't find any on Mars, that's a huge deal.
Mars is just
so inhospitable.
The surface is being bombarded by ionizing radiation,
which is not good for life or organic molecules.
Not good.
It tends to break them down.
Every sample was a bit of a risk scientifically
'cause we didn't know what we were gonna come across.
I mean there were samples where we
really didn't learn much of anything.
If we had the conditions for life to survive,
we would expect to find organic material.
We still hadn't seen any with Curiosity
and this was a big mystery.
Was there never any organic material on ours?
Our best hope was to just keep looking.
We came across a bunch of cobbles
and stones that were all rounded.
The best way of doing that is in a river.
We realized there had been water flowing
on the surface of Mars in the past.
Then we knew we were on the right track.
We were heading to where we thought the lake was.
We saw these features and they sort of indicated
that there was shallow water.
Shallow water is a great place for life to do its thing,
get immediately trapped into the sediments.
So I was particularly interested in that sample.
And when we drilled into the first rock,
the sediment was dark gray.
It hadn't been rusted like everything else
that you see on the surface of Mars.
And there was a window into the past.
There was organic matter in that rock
and that it had survived eons
of ionizing radiation at the surface of Mars.
The discovery of organics
is a huge step forward in establishing
the habitability of Mars.
But falls short of proving life ever existed there.
Finding organics is not proof of life on Mars at all.
It's a nice hint, but we don't know
whether these organic molecules actually rained down
on the surface of Mars in the form of meteorites over time.
Okay, great.
We finally have found organics on Mars,
but it doesn't tell us anything about
where those molecules came from
and what they're doing there and what they mean to us.
Because of missions like Curiosity,
we know that Mars was absolutely habitable.
So the next question is was it ever inhabited?
Back on Earth,
a radical new mission is being prepared.
The goal of the Perseverance Rover
is to look for signs of ancient life on Mars.
We finally put together the pieces
of what Mars used to to be like
and we know what evidence we need to definitively say
whether there was or wasn't life on Mars.
So Perseverance's goal is to take us to that next step.
The purpose of Perseverance Rover mission
is to find some ancient traces of life from us.
And, for that purpose, the instruments need
to be different from the Curiosity Rover.
And we need to have more techniques to meet this requirement
and that's a price to pay to be on board.
But how do you begin to unravel
the clues that point to life?
On the end of Perseverance's robotic arm
is an instrument called SHERLOC,
designed to take Curiosity's investigations
into organic molecules to the next level.
Curiosity has a mass spectrometer
and that's one way of detecting for organic molecules.
What we do is something a little different.
We are looking for spectral signatures.
We shine a laser on a surface,
and then we look at the back scattered light coming back
and how that light changes tells us what's in the surface.
They detect and classify organic molecules
on a very fine scale.
The astrobiologists are going crazy for this instrument
because the wavelength at which the spectrometer operates
is optimized for organics.
On the opposite side
of the robotic arm from SHERLOC,
is an instrument called PIXL,
a radical reimagining of a geologist's most basic tool.
I sometimes refer to it as a chemical hand lens.
You know, the hand lens being the eye piece
a geologist uses to look at the rock.
Imagine being able to look through that and see,
not just what the rock looks like,
but also what it's made of.
PIXL uses spectroscopy to create
a chemical map of the surface,
to reveal how life might have affected the rock.
In a way it looks like a camera image,
but it is really the fingerprints of the rock.
And in turn those fingerprints tell you
the history of the rock.
How it was formed, what environment it was in.
The PIXL instrument was something that arrived
from doing field geology out in Western Australia one year.
Trying to look for evidence of life
in the oldest rocks on Earth.
I found that trying to figure out on Earth
whether something that was in a rock
that was possibly biological was actually biological
was really helped by this instrument
called an x-ray microscope.
It's like a huge...
A pretty decent sized beach ball.
It's connected to the mains power.
And, of course, if anything goes wrong with it,
then you get a crew come out to fix it.
The most challenging aspect of building PIXL
is the not being able to break.
You have to be able to get off the surface of Earth,
to Mars, land on the surface of Mars
and then survive on Mars for the entire prime mission
and hopefully well beyond.
All of that had to be done
in addition to getting it down from 80 centimeters cubed
to about 20 centimeters cubed.
There were certainly moments where it was like,
my God, how complicated is this becoming?
Tailoring these precision instruments
for a future on Mars is a daunting engineering challenge.
Even for those who have been there before.
To develop an instrument for Mars is pretty easy.
You just have to worry about every single thing
down to the bolts and where the bolts go
and where the bolts don't go.
Most instruments that are SHERLOC-like
do not like vibration.
And we're attached to a drill that vibrates.
The temperature swings on Mars every day
is a hundred degrees Celsius.
Electronics really don't like to be hot, then cold,
then hot, then cold, then hot, then cold every single day.
And the brutality of the Martian atmosphere
is matched by the trauma of the space flight
that will get them there.
We do testing informally known as shake and bake, right?
Because you wanna shake it
and you wanna heat it.
Everything that goes into space
has to be really thoroughly tested.
You could almost say violently tested.
We vibrate it at different frequencies
and make sure no screws come loose,
nothing falls apart.
When I saw the shaking, I was like, my God,
what about the optical alignment?
It's a bit heartbreaking to see your instruments
suffering like that.
The jewel in the crown
of Perseverance's instruments is the eye catching SuperCam.
SuperCam is often described as the head of the Rover.
And it is, it's sort of this cyclops laser eye.
SuperCam's long range, rock busting laser
could make all the difference in the search for life.
We can shoot the laser at a rock
up to seven meters away from the Rover.
So we can actually analyze things
all around us without having to drive up to it.
The rock gets literally zapped
and the atoms come screaming off
at 10,000 degrees in a plasma
and then, with that cyclops eye,
we collect some of that light.
We can tell what are the chemical elements
that are present in that rock?
It blows my mind that a scientist in a lab one day
thought let's blow up rocks with lasers
and see what they're made out of
and now we're doing this on Mars.
Just below SuperCam
are two stereoscopic cameras,
the key to navigating Martian terrain,
with the driver using special 3D glasses.
So, as a Rover driver, I'll put on my 3D goggles
and getting the three dimensional data
allows you to really visualize the terrain
in order to determine if something's a hazard.
And on Perseverance, the cameras are fantastic,
very high resolution, so we'll be able to see a lot further.
The complex optics for SuperCam
and the entire head of Perseverance
are made in Toulouse by the French space agency CNES.
At the end of 2018, the launch is in sight.
But the future of NASA's cyclops eye
is about to be thrown into doubt.
We had a phone call every Tuesday with JPL.
We had a small modification to do on the instrument,
just be for delivery.
We were actually on the phone talking about
final touches that they were doing
on this beautiful masterpiece.
And it happened during this phone call,
my test team in Toulouse called me saying
we have a big problem.
The last stage of the modification to SuperCam
is to heat treat the glue used during final assembly.
To make sure that the bonding is done correctly,
we put the instrument into a small oven
and we bake it at 50 degrees Celsius.
That's what we did.
But we had an issue with the hardware, the thermal chamber.
The thermal couple in that furnace broke,
went to its maximum temperature.
It was a disaster.
Basically, we destroyed
all the optical parts of the mast unit.
Two months before they'd agreed to GPL.
I was still on the phone call with GPL.
We started to realize that the people
on the phone in France were very distracted,
said, this thing is destroyed.
And we had just a few months to go.
If something breaks on your flight model,
that could actually end your mission.
Part of the problem is the launch window for Mars
opens up every 26 months.
If we miss this launch opportunity,
we gotta wait 26 more months.
Probably Mars 2020
will launch without us.
But that's where we are, now what can we do?
SuperCam is a write off.
The team's only hope of hitting the launch deadline
is to somehow repurpose existing hardware.
And they have one chance to pull this back.
In parallel to building the SuperCam flight unit,
we were also building a laboratory unit almost identical
so we could do experiments on Earth during the mission.
We had to take that laboratory unit
and try to make it flight worthy.
But we had to constrain everything in six months
instead of one year taken to build the first model.
It is really a last ditch effort.
It was like, we've gotten this far
and then we're not gonna make it.
We had to work days and nights the weekend and everything.
But in six months we had a new SuperCam mast unit.
Honestly, I'm so happy to see
the performance of the instruments,
it's really a perfect instrument.
As Perseverance
is packed and prepared for launch,
the mission is entering is most uncertain phase,
where history has lessons for those
choosing to visit other worlds.
Getting to Mars is no easy task.
You have two moving targets, Earth and Mars,
and then you're throwing in the third moving target
of the thing you're trying to get
from one planet to the next
at thousands of miles an hour.
Schiaparelli was a technology demonstration,
a tiny lander that was Europe's first attempt
to land on the surface of Mars.
Everything had been going right
up to the point of parachute deploy.
Supersonic parachute inflation, that's a very violent event.
Was swinging too fast underneath the parachute.
Couldn't figure out which way it was up.
Unfortunately for Schiaparelli,
was like stealing defeat from the jaws of victory.
Schiaparelli ended up smashing into the surface of Mars
and left a nice little splot in the dust
that we could see from orbit.
Schiaparelli hit the ground going much faster
than it was designed to do.
And we call that creating a new crater on Mars.
And we felt, you know, really horrible for them
'cause you know, there's years of work that went into that.
You know, it was a terrible feeling.
It was just like another crash on Mars and we could be next.
The team on Perseverance looked at Schiaparelli
as very much a reminder of just how hard this really is.
Ten, nine, eight,
seven, six, five,
four, three,
two, one.
The 58 meter tall Atlas Rocket
is only just powerful enough to deliver
the one metric ton Rover to Mars at its closest approach.
Even so, the journey will take seven months.
Yeah!
Woo.
In the meantime,
investigators turn their attention to the landing site
that they believe offers the best opportunity
for finding ancient life.
Jezero crater is tucked along the western edge
of one of the largest basins in the northern hemisphere.
If there was ever life on Mars,
then a place like Jezero is gonna be spot on.
Absolutely perfect to preserve evidence of life.
Jezero has long been on the list
of top possible landing sites
because it looks like there was a long lasting lake,
a body of water.
But the problem is that incredible topography
is also incredibly dangerous for spacecraft.
If you look at Jezero, there's just so many hazards,
there's a delta with really steep cliff walls.
Scientists want to go to places
that have a lot of topography, that have a lot of rocks.
But, as a guy who's trying to land Rover safely there,
when you look at all those things, you just see danger.
Perseverance has a new technology called
Terrain Relative Navigation that recognizes
hazards on the ground and takes avoiding action.
Terrain Relative Navigation
means that Perseverance can tell
whether there's a mound or there's a hill
or there's some other thing
that the Rover could possibly land on that would be bad
and it steers the Rover away from that.
And that's the only reason we could land in Jezero crater.
Without this navigation system,
you should expect that about 20% of the time,
you're not gonna make it.
Although the new technology
has been tested extensively on Earth,
this will be its first time operating in concert
with the entire landing system.
It's humbling right?
To realize that the first time you get a chance
to use your whole system is going to be
when it has to work at Mars.
On February 18th, 2021,
Perseverance is poised to enter the Martian atmosphere.
Now, 293 million miles from Earth,
the delay in communication
means the spacecraft must act autonomously
during the seven minutes it will take to land.
That's seven minutes from when you hit
the top of the atmosphere, going 12,000 miles an hour,
until we touch down,
there's literally nothing we can do.
We're just finding out what has already happened
about 11 and a half minutes ago.
We have spent more than six years
developing the instrument and you know that,
in seven minutes, everything can change.
Either you have the Rover on Mars
or you lose everything in seven minutes.
Perseverance is on her own.
But sends status updates back to Earth
in the form of a tonal code, similar to musical notes.
So it's kind of like it's singing
a little song to us on the way down
and each of those notes means something different.
You know, if you hit this note,
that means we deploy the parachute
or if you hit this other note,
it means something has really gone bad with something.
You wait for that telemetry
to come back and see what it tells you.
And if you're not getting the readings that you expect,
your heart just sinks into the pit of your stomach.
10 minutes before we get to the top of the atmosphere,
she tells us that something's gone wrong
with one of the electronics boxes, one of the computers.
All stations at this point,
let's limit our traffic on the net to critical issues only.
If Perseverance was right,
that something was wrong with that box,
we would lose the ability to fire thrusters
and the propulsion system not working
would be certain death.
Perseverance is actually being
pulled in by gravity and accelerating.
The mission would be over, no question.
There's a lot of silence in the room.
Everybody's monitoring that telemetry so carefully
knowing that we'd done everything we could.
And yet this
belief that it'll recover
and we continue to have a mission.
A vehicle slams into the atmosphere
going at about 5.4 kilometers per second.
On the outside of the vehicle,
we're getting white hot like the sun.
All we can do is take a look at what
Perseverance is telling us and worry.
Are your engines really gonna work
or are we about to fall to our death?
Luckily the spacecraft began to do things
that were consitent with the box working
because all of our thrusters seemed to be working fine.
So crisis averted for the moment.
But it definitely got our hearts beating.
The navigation has confirmed
that the parachute has deployed
and we are seeing significant deceleration.
We had cameras all over the place,
looking up at the parachute.
This was extraordinary.
This was a documentary.
Our current velocity
is 480 meters per second
at an altitude of about 12 kilometers
from the surface of Mars.
We're approaching at the mercy of the winds
and at the whims of the rockets.
If we happen to land on a too large a rock,
the mission is over.
Heat shields up.
Perseverance is now slowed to subsonic.
Our new system called Terrain Relative Navigation
allows Perseverance on her own to figure out
exactly where she is by taking pictures of the ground
and matching them up with an onboard map.
We light up rocket engines on that jet pack to slow us down
and steer us to the nearest safe spot that we can find.
Current velocity is at 75 meters per second,
at an altitude of about a kilometer.
But right after that, you can hear
one of my teammates call out tier end safety level problems.
Tier end safety bravo.
What that was telling us was that
Terrain Relative Navigation has done its job.
But the best place that it could land
was not the best case scenario.
It could no longer go to where we had originally targeted.
That causes us to freak out again.
Suddenly you're thinking, my chances
just dropped to one in 20
that we're gonna die at touchdown.
Perseverance flew about 600 meters to the southeast region.
If one thing goes wrong, its game over.
Skycrane maneuver has started.
20 meters above the ground,
we deploy the Rover and its wheels
below that power jump pack.
You have so much riding on this, like whether,
as a Rover driver, you are actually going to have a job
all depends on this landing.
It's nerve wracking the whole time,
all of those little black things
that were coming by the camera, I called those projectiles
that might have hit my instrument.
That's the fear.
We had our fingers crossed all the way through touchdown
that we had found a safe spot.
That skycrane let the Rover touch the ground
and then cut the cables and fly away.
Touchdown confirmed.
Perseverance safely on the surface of Mars.
People are jumping up and down elated.
So, to some people, landing looked perfect.
But I mostly just felt a massive sense of relief.
As soon as they gave us a coordinate,
we were able to load where the Rover is.
You're like, what is Jezero like?
You're curious about seeing the terrain.
You put on the 3D goggles
and it really transports you as if you are on Mars,
standing there from the perspective of the Rover's cameras.
It's very immersive.
Jezero was really spectacular
from the first image that came down.
I think I did that for hours.
Once we landed, the first thing I said
to my engineering team was, God, now it has to work.
So our stress like started increasing.
The investigators run calibration checks
on the instruments to see if they've survived the landing
and test the lasers on nearby rocks.
We went for a target
just a few feet in front of the Rover.
Made a nice target because we couldn't miss.
We were crossing our fingers,
praying that everything's gonna work.
When we saw the atomic emission spectra,
that was the moment of truth.
The spectra revealed
that the test rock is a basalt
common in ocean basins on Earth and across Mars.
The result confirms their hunch
that this was once an ancient lake.
But there's nothing to suggest life
ever existed here in the landing zone.
However, Perseverance is just a few kilometers
from the spectacular features
that brought it to Jezero crater.
So we landed right in front of a river delta
and what we're going to do is drive up this river delta and,
along the way, we're gonna take samples
and do scientific analysis on the rocks.
A delta forms when you have a river
that empties into some kind of standing body of water
and all of the material that was being transported
by that river stops moving
and sinks to the bottom and forms these layers.
Our experience from previous missions
is that this fine grain material is good
for finding clay minerals,
which might then contain organic molecules.
You can think about water being trapped in little ponds
and puddles around the place.
That's the kind of complexity that can eventually tell you
will lead to a discovery of life.
The delta has been dry
for probably three and a half billion years
but how would it have looked when water still flowed?
I imagine if I was sitting on the edge of Jezero crater,
just looking out over the lake,
when it was there four billion years ago,
you would have this very peaceful environment.
You might hear the sound of the river coming into the lake
on the side where the delta is.
It would probably just be this beautiful place.
I would love to think that maybe there were
some kind of fish or algae living in there.
I would love to see us discover a fossil
of some kind of plant, even if it's really unlikely.
You never know.
I wouldn't count it out.
We know that Mars was once a very different planet,
but there has been a lot of changes happened on Mars
since Jezero crater was formed
and since that huge fresh water lake was deposited.
Mars today is drier than the driest places on Earth.
In addition, the very extreme incoming radiation
would be an incredibly harsh environment,
even for the most hardy microbes on Earth.
But how did Mars become so hostile to life?
The answer will give clues
about where traces might still exist.
And investigators have focused on a critical period
when Mars had a molten planetary core like Earth does today.
Inside Earth, we have a molten core
and that spins around and generates
outside of the planet, the magnetic field,
and that magnetic field protects our planet
from the blast of ionizing solar wind coming off of our sun.
Protects us, protects the whole biosphere.
Now on Mars, it had that molten center
just like Earth does today.
But something happened on Mars
where that started to solidify around 3.9 billion years ago.
All of a sudden, the magnetic field stopped
and the solar wind blasted the atmosphere away.
It literally blows it away.
The moment the magnetic field was gone,
ionizing radiation had a huge impact on the surface.
And, forever more,
Mars was a completely unique, different place.
Perseverance Rover has a top speed
of just 0.1 miles per hour
and the journey to the delta is expected to take two years.
But before the search for life can begin,
Perseverance drives to a nearby flat expanse of regolith
where it will drop off a passenger.
Perseverance didn't go to Mars alone.
It took with it this tiny little drone called Ingenuity.
Underneath the belly, Ingenuity is sitting sideways,
the legs swing down, and then we drop to the surface
and from that moment on, there's no way
to come back to the Rover and reattach the umbilical.
Our mission had begun.
This 1.8 kilogram experimental helicopter
could prove invaluable as an aerial scout
in the search for life.
If it works.
There's a lot of challenges when it comes
to flying an aircraft on Mars.
One, the atmosphere is very thin.
It's one percent that of Earth's atmosphere,
there's almost nothing to generate lift with.
Back in 2014, the first prototypes
struggled to deal with the simulated Martian atmosphere
created in JPL's laboratory.
So how will it cope on Mars?
It's as if you operated it on Earth
at a hundred thousand feet, at 20 miles, high
and tried to fly.
Ingenuity was a total mystery to us.
Was it gonna work?
It doesn't carry any science payload.
The one and only purpose of Ingenuity
is to prove that we can fly on Mars.
And Martian weather is the wild card
that could make or break Ingenuity.
Mars can be a gusty place.
And so we were not sure how that turbulence
might affect this helicopter.
And perhaps the biggest threat to Ingenuity
is from Martian tornadoes.
We did see some pictures of Ingenuity
with a dust devil in the background.
Dust devils could probably do a number on that helicopter.
So today's the day of our first flight
on the surface of Mars.
We have sent the commands up the day before
and everyone's holding their breath.
Definitely very nerve wracking.
Equations tell you that you can get lift
if you make it light enough,
if you make the propellers big enough,
but can you control the flight?
That's another story.
Even taking off would've been a massive success.
The sheer power of the rotor system
to fight itself off the surface and produce lift.
It was awe inspiring.
The plan for the first flight is take off, hover,
come back down and land.
That's it.
Yeah!
Woo!
It came down on its feet, not on its side.
And so we were really applauding.
This is a big relief.
We did it, our mission is successful.
We have proven we can fly on Mars.
Ingenuity is now off scouting for the Rover.
One of my absolute favorite ideas
is to descend through a skylight hole,
into a lava tube cave on Mars.
That was never thought to be feasible
before this Ingenuity mission.
The fact that we flew this helicopter,
this drone helicopter on Mars
was really awesome for all of us.
NASA's faith in Ingenuity
has given them an eye in the Martian sky.
Now the search for signs of ancient life can begin.
But what exactly should Perseverance be looking out for?
Scientists have been trying to define what life is
for decades and they still are talking about it.
So there is no one clear definition.
The problem with looking for life is
there's a lot of problems with it.
The definition of life, it always uses the phrase alive
somewhere in the definition of it,
which is kind of circular and it doesn't make any sense.
Looking for life on Mars,
we have to make certain key assumptions.
It would be really hard to recognize a form of life
we've never imagined or encountered before.
So we start looking for something familiar.
But the problem is that, even here on Earth,
where we have plenty of life to study,
it's really hard to actually tell the difference
between chemistry, complex chemistry and life.
My idea of life is organisms
actually change the environment, they do things.
It's not like they deliberately think about doing this
but life chooses certain things that it wants.
So when we go look for life,
I look for indications of something very specific
that wouldn't be there if it weren't for life
needing that specific thing.
One thing that the investigators can agree on
is that the clues that point to possible
ancient life are called biosignatures.
Biosignatures are things that are left behind by life.
So the thing that was alive to have produced
whatever you're looking at isn't necessarily there anymore,
but you can tell it was there based on traces that it left.
We're trying to find potential biosignatures.
So we wanna look for places that, at one point,
had what we think life needs.
So we're looking for hydrothermal material,
minerals that could only be created
in the hydrothermal vents.
We're looking for carbonates, we're looking for things
that we know on Earth biology likes.
If we found something that looked like a hydrothermal vent,
we would stop and look at it for months I would hope.
Hydrothermal vents
that result from volcanic activity
are associated with life processes on Earth.
But Perseverance is also looking out
for bulbous rock structures called stromatolites,
a feature of Earth's most ancient landscapes.
So stromatolites are great because they're macroscopic
and I think they're like the tip of the iceberg
that alerts you to, hey, you know, look here.
They're really rock formations but they have within them,
organic carbon mixed with the rock layers
that were the sediments.
Life on the Earth tends to clump
and on Mars, we would expect the same thing.
Lakes lay down layers, they lay them down flat.
It's hard to imagine without biology how those things grow.
So life can alter the appearance of rocks.
A biosignature carved into the landscape.
But, on Earth, microbes can also affect
the abundance of certain minerals and rocks.
Could the same be true on Mars?
When you think about the things
that life needs to survive, you probably think of water,
maybe plants living off sunlight,
but there are actually microbes
that can live off of eating rocks.
If you ask a different scientist,
you'll get a different answer.
But my particular biosignature of interest
is a family of minerals that are high
in the element manganese.
Here on Earth, microbes absolutely love manganese
because it has a lot of really critical chemical properties
that they can use to actually do their metabolism.
Microorganisms have this amazing ability to adapt.
They are capable of getting energy in so many unique ways,
give them a rock and they'll figure out how to use it.
On Earth, high concentrations
of manganese oxide have been linked
to the presence of ancient microbial life
and a similar over abundance of this mineral
has already been found on Mars by earlier missions.
These minerals tend to form little bumps and crusts.
You'll just roll up to a new spot
and suddenly there is manganese.
And now Perseverance
is discovering signs of more deposits.
As we look through SuperCam data, we can see that
there is manganese in these rocks in Jezero crater.
It literally is the very first time we shot a rock,
you could see manganese in it.
You know, this is very intriguing.
It's not proof that life did this on Mars,
but we can start looking for other things
that can start building that case
that maybe life made these materials.
Perseverance's instruments are designed
to recognize the subtle imprint of microbial life
and the familiar chemistry of organic molecules.
But the devastating effects of ionizing radiation
add another level of complexity to the challenge
of locating biosignatures.
We joke about the fact that it's planet bleach.
Life as we know it needs water, an energy source
and organic carbon.
But Mars is a very bad environment
for a lot of organic molecules.
If there was life there, would that site
have preserved the evidence in a way
that we can find it today?
The challenges facing the robotic search
for life on Mars may appear overwhelming,
but Perseverance has come prepared
to tip the odds in its favor.
If we're going to find evidence of life on Mars,
we may get an incredibly lucky and do it on Mars,
but far, far more likely it's going to be in a laboratory
with proper equipment back on Earth.
And so Perseverance is an entirely
unfamiliar kind of mission.
Yes, we're driving around, we're looking at rocks,
we're doing science on rocks,
but it's being done to select samples,
take small drill cores from those samples,
put them in hermetically sealed containers
and leave them behind for a future mission
that is only now being planned.
An international mission to retrieve
and bring back to Earth, hopefully within the next decade.
The sample's about the size of your index finger.
And then you go and you unleash
all the power of laboratories on Earth
and try and look at even smaller scale.
This is really important because we can
actually take those samples
and look for signs of DNA in them.
And DNA is irrefutable proof of life.
We can tell you that it was not something
that came from Earth, it was something
completely native to the Red Planet.
Perseverance's instruments work together
to identify potential samples for return.
But trying to operate completely new hardware on Mars
is proving to be an ongoing challenge.
The stress never gets any less.
We're turning ourselves on today
and we're gonna do some spectroscopy on the surface.
I'm petrified that it's not gonna work.
I used to have an old car and every time I would go out
and turn the old car on, it's the same feeling.
Is this the time the car is not gonna start?
Mars is living up to its reputation
as an unforgiving host for even the night itself
is just another hazard to contend with.
What happens is, as soon as the sun goes down,
the temperature plummets,
the metal that the Rover's made of starts to contract
and the arm starts to move and drift down,
and that drift was actually not at all trivial.
PIXL needs 17 hours to create its detailed
microscopic maps of rock surfaces
and the sample must remain motionless
under the sensor for the whole period,
which created a headache for engineers
during the development of PIXL.
So we actually had to invent a new thing called a hexapod.
Like a six legged device,
legs that would sort of get longer and shorter to make sure
that you can stay the right distance from the rock
and actually stay over the right part of the right.
The ingenious engineering is put to the test
seven months into the mission
when the team must decide on
where to drill for a sample core.
The first stage is to grind the clean surface
so the rock can be tested.
It's really cool because you see a rock
that's completely different than the rock
you see on the outer surface.
It's pristine, it's not weathered, it's not dusty.
You can see individual crystals.
They're not tiny, they're actually really big.
It looks like it's a volcanic rock.
But there are some other smaller features
that are a little bit harder to resolve.
You have to go for a closer look.
When PIXL scans the surface,
four billion years of history is exposed.
PIXL can make us an incredible map
of the chemistry of this area.
We can see that these smaller features appear to be salts.
Crucially, the presence of salts
means the rock has spent time underwater.
But what nobody is expecting
is the presence of calcium phosphate.
What's so interesting about calcium phosphates
is that they form in some
very unusual environments on Earth
and, in general, they're very closely associated with life.
Phosphates have never before been discovered on Mars.
And so that makes them incredibly intriguing
to discover in Jezero crater.
The team decides to drill for a rock core
to return to Earth.
This sample could rewrite Mars history
and some believe that the salt could even contain
a microscopic hoard of lake water.
These types of salty materials in rocks
can preserve traces, little bubbles of water,
from when there was more water,
when these materials were being in placed in the rock.
And so these little bubbles of water
can preserve organic materials
so it's worth a look in these Martian samples.
The rock sample is stored,
ready to be dropped off.
The first of more than 30 tubes
destined for Earth laboratories.
The next step in solving a mystery
that began perhaps four billion years ago.
All of a sudden, Mars goes through
this incredibly dramatic change.
Something on a planetary scale
that we haven't experienced on Earth.
Did life survive, if it had been there?
Life does things with its environment.
We're looking for signs that organisms
are actually influencing what's around them
in a way that their natural environment
wouldn't do so on its own.
The whole biosphere has affected the planet,
have affected the mineral formation, every thing,
and that has got to be recorded in the rock
in some way, shape or form.
I think.
There should be something that we can decode from that.
It might take decades.
Mars is a entire planet you know?
A planet like Earth, full of diversity,
of all kinds of things we can't imagine.
So in a way, what I expect is the unexpected.
I'd like to know why Mars didn't have life
or why Mars did have life.
We're an exploration species and we want to know
where we fit in the universe.
Either answer is wonderful.
Are we alone?
Is there life out there or is life so special
that it's only here on Earth?
We might find evidence of that randomness
that defines the non-biological world.
If there is evidence of life having once existed on Mars,
then that tells us that life can exist on a planet
and then it can disappear.
That's pretty...
That's the reason why we're doing this.
You can't rely on your planet to always provide you a home.
Every time we look at Mars in a different way,
we discover something grand.
But do I think that the samples
have evidence of life in them?
Depends on what day you ask me.