All language subtitles for 59135DBD7E489E61410C171A1B8DF4B8_eng

- Mars.

The god of war

and the source of man's
science fictional demise.

It has fired our imagination
for thousands of years.

We know the dry, barren
planet was once flowing

with vast reservoirs of water,

the sky thick and filled with clouds,

and the tantalizing possibility of life.

It is the only other
place in our solar system

that man might one day call home.

We Earthlings have fired
numerous probes and satellites

towards the red planet,
an invasion of sorts,

not for conquest but for knowledge.

What happened to Mars?

Is there or has there ever
been life on the planet?

- A fundamental question
that needs to be answered,

is life as we know it on Earth,

even the simplest type of
microbial life, unique?

If we were to go to Mars
and we were to find evidence

of early microbial life
or maybe even present life

that somehow survived in the near surface,

would it be the same as the early life

that developed on Earth?

That's a very fundamental question.

Does life emerge generally in planets

where the conditions
for life are favorable

if we find out that they
were favorable on Mars

or might life take its own unique path

in different environments
and turn out differently?

- We have bombarded Mars
with satellites and landers,

but there have been more
failures than successes.

The Soviets established two Mars orbiters

while NASA landed two Viking landers

carrying complex analytical laboratories

and search for signs of microbial life.

Their findings were inconclusive.

Further missions to Mars still
had a high mortality rate,

but the successes were outstanding,

with robotic probes operating for years

beyond their initial missions.

In fact, Mars is a planet occupied solely

by robots on the surface

and satellites peering down from above.

All these instruments perform admirably

in their specified fields of endeavor,

giving us a much clearer
picture of the planet

and its history.

The science was following the water,

what happened and where it is now.

- Thanks to the specific instrumentation

on board the mission,
we are able to tell us

what kind of ice did we find.

And the result is that there is a mix

of CO2 ice, or carbon dioxide ice,

and water ice.

And it's very important
to characterize it,

especially for the water
ice, or frozen water,

because one of the main objective

of any mission to Mars
is to trace the water

on Mars in every form.

Liquid, if possible, solid, water vapor.

So it's very important to study the ice

because it's one of reservoirs
of water on the planet.

- The science was conclusive.

There was water on Mars.

There were ancient lakes
and rivers, even an ocean.

We needed to learn more.

With the advancement of
analytical technology,

computer power, and robotics,

a new rover was constructed.

Big, complex, and heavy,
it required a new way

to land on Mars safely.

Engineers came up with a system

that couldn't be fully
tested here on Earth.

It required a lot of
things to happen correctly,

on time, and in order.

This was the sky crane

and the rover, Curiosity,

was the first to try it out.

A controlled reentry with heat shield,

aerobraking with a parachute,
all pretty standard.

Then a rocket-powered sky
crane drops from the aeroshell

and gently descends toward the surface,

spooling out the rover below on cables.

The rover touches down, cuts the cables,

and release the sky crane to
fly off and crash harmlessly.

The Curiosity rover has
been an astounding success,

traversing the terrain for over 10 years,

taking samples, drilling,
and studying rock formations,

zapping samples with a powerful laser,

and photographing its progress.

- Now, in the belly of that rover

is an instrument called SAM.

It's an instrument suite that has

a couple different instruments
in it that allow us

to look at different types of gases.

It helps us understand
the chemical composition

of the atmosphere and of
minerals that might be found

in the rocks and the soils on the surface.

In particular, it helps us
identify organic molecules

that might be present.

- So, the sort of evidence
we're looking for,

sort of signatures of past life

that we would be looking for

would be signature of microbial life.

So, not realistically
looking for dinosaur bones

and that kind of thing.

If life ever existed on Mars,

we expect it to have been
microbial, microorganisms.

- Orbiters including Mars
Odyssey and Mars Express

have been hunting down
life as well, from orbit.

- After 10 years of mission,

we have achieve a global view of Mars

and then we know what every
location on the surface,

if you find some special minerals or not.

So we have really the global view

that tell us the history of Mars.

Mars Express has, for the first time,

detected methane.

And also it comes from
pressure in the atmosphere,

vary from the place to another,

from a season to another.

And this discovery, it's been very debated

in the scientific community

because, in fact, methane
should not be there

because it's being
destroyed in the atmosphere

by the ultraviolet radiation.

So if methane is there,
there must be a source

of methane and for the time being,

the origin of this source
is largely unknown.

- However, with Curiosity
prowling around Gale Crater,

it too detected seasonal methane.

- Now, methane has been found previously

in the Martian atmosphere by
both Earth-based telescopes

and space-born orbiters,

but this is the first time
that we've actually seen

a sharp increase and decrease
in the abundance of methane

in the atmosphere in Gale Crater.

But what this really means
is that present day Mars

is an active environment.

- The big question is what
is the origin of this methane

now being released?

The two principles areas are first,

by analogy with the Earth,

it could be released unproduced initially,

primarily by biology.

This would be microbial activity

acting on certain
chemicals below the surface

and then producing methane as a byproduct.

But of course we can't stay with certitude

that it is biologically produced.

And so we also consider
geochemical mechanisms

in which carbon dioxide
is actually combining

with water and producing methane

under very high
temperatures and pressures.

And that methane can then be released

in the atmosphere separately.

- Now, at this point we
don't have enough evidence

to tell us whether or
not the organics refining

are biological or nonbiological in origin.

There are several viable
nonbiological explanations,

including this organic
material could've come down

from space, from meteorites or comets,

or organics can be formed
by geological reactions

in the rock itself.

Now what's exciting about this discovery

is it gives us new hope in the search

for chemical evidence of life.

We found the organic material.

Now the next step is trying to figure out

what its origin is.

Main engine start.

Ignition and lift off

of the Atlas V with MAVEN,

looking for clues about
the evolution of Mars

through its atmosphere.

- The latest NASA
orbiter mission is MAVEN.

Launched in November 2013, it
made orbit 10 months later.

- MAVEN is the Mars Atmosphere

and Volatile Evolution Mission.

Our goal is to study the
role that lost to space

has played in the history
of the atmosphere.

Where did the water go?

Where did the CO2 go
from the early planet?

These are important
questions to understand

how Mars went from an
early warm, wet environment

to the cold, dry environment we see today.

- There's evidence of
water flowing on Mars

at one point in time,
perhaps even oceans on Mars.

And what happened that it's so
barren at this point in time?

And a key part of that is the atmosphere

and it's a much thinner
atmosphere than what scientists

believe it was at one point in time,

so the stripping away of
that upper atmosphere,

that's what MAVEN is going after,

the climate change at Mars.

- One of these processes
is called sputtering,

where atoms are knocked
away from the atmosphere

due to impacts from energetic particles.

The sun constantly emits
high energy photons.

When these enter a planet's atmosphere

it can crash into a molecule,

knocking loose an electron
and turning it into an ion.

When this happens in the
presence of a magnetic field,

the ions are captured and
spin around the field.

Conveniently, the sun generates
a giant magnetic field

that is carried by the solar wind.

As the magnetic field
sweeps past the planet,

these ions are carried away.

Depending on where they form,

other ions will not be carried away

but will hit the top of the atmosphere.

These ions crash into other molecules

and fling atoms everywhere.

Some of these atoms can be
knocked or sputtered into space

causing atmospheric loss.

As this process continues
over billions of years,

Mars' atmosphere has disappeared

and along with it, the water.

How much water has Mars lost this way?

- We use the world's
three majors telescopes

for infrared astronomy.

From the ground we could
actually take a snapshot

of the whole hemisphere of
the planet on a single night.

- Water naturally carries a heavy isotope

of hydrogen deuterium,
which remains trapped

in the water cycle while normal
hydrogen is lost to space.

Detecting the amount
of deuterium enrichment

tells us how much water has been lost.

- Now we know that Mars'
water is much more enriched

than terrestrial ocean water

in the heavy form of
water, the deuterated form.

Immediately that permits us to
estimate the amount of water

Mars has lost since it was young.

- So in the ancient past,
when you have some indications

that water was flowing on the surface,

but how much water was there?

Talking about oceans, I'm
talking about small rivers,

little rain.

So these definitions of how
much water was on the planet,

it was very undefined.

- A major question has been
how much water did Mars

actually have when it was young

and how did it lose that water?

- The findings indicate that
only 13% of an ancient ocean

remains on the planet today,

now stored in the polar ice caps.

87% of this ocean has been lost to space.

This means that early Mars
would have looked much different

than it does today, with
a significant portion

of its surface covered by water.

- So the really interesting question is

could it form a sea or an ocean?

And indeed, it would.

In the northern plains, which
is a relatively flat region,

but depressed from the rest of the planet,

it would form an ocean
that was approximately

20% of the planet's surface area.

And so that is a respectable ocean.

- This ocean had a maximum
depth of around 5,000 feet

or around one mile deep.

It's deep, not as deep as the
deepest points of our oceans,

but comparable to average
depth of the Mediterranean Sea.

- By combining Martian
topography with a new estimate

for water loss, the researchers
were able to simulate

Mars's ancient ocean
and its escape to space.

As Mars lost its atmosphere
over billions of years,

it lost the pressure and heat
needed to keep water liquid,

causing the ocean to shrink
and recede northward.

The remaining water eventually condensed

and froze over the north and south poles,

giving Mars the ice
caps that we see today.

- We now know that Mars was wet

for a much longer time
than we thought before.

Curiosity shows it was
wet for 1.5 billion years,

already much longer than
the period of time needed

for life to develop on Earth.

And now we see that Mars must've been wet

for a period even longer.

- It's fascinating that
we can learn so much

about 4.5 billion years ago
with measurement taken right now

and ultimately we can conclude this idea

of a ocean covering 20% of the planet,

which opens the idea of habitability

and the evolution of life on the planet.

- Building on this knowledge,

scientists are developing the
next series of robotic probes

to be sent to Mars in the coming years.

This time, NASA is
building on its successes,

utilizing hardware and systems
that they know will work.

- We've been to Mars before

with the JPL, Lockheed Martin team.

We've been to the surface
of Mars before successfully

with Phoenix.

We know how to operate the arm.

The surface operations are
much, much simpler than Phoenix

and we're putting two
instruments on the surface

and then we're leaving them there

with no ground-in-the-loop interaction.

Repetitive weekly up
link, down link sessions.

We're just made to do this mission.

- The InSight mission is a
geophysical mission to Mars.

It's gonna go to Mars
and take its vital signs.

It's gonna take its heartbeat,

the seismic activity of the planet.

- So we're gonna be doing
that using a seismometer,

a very high precision seismometer.

Using techniques that have
been well-developed on Earth

to get the understanding of
the crust, mantle, and core,

and sort of the
relationship between those.

- Gonna take its temperature by measuring

the thermal gradient of the surface,

which tells how much heat is coming out.

And we also have a heat
flow probe called HP Cubed

and what that does is
it's gonna basically take

the temperature of Mars
and from that it'll be able

to understand what the thermal flex is

over the course of a full Martian year.

- And it's gonna sort
of measure its reflexes

by looking at how the rotation wobbles

with the tiled effects of the sun.

- Our final experiment is called RISE

and that's going to be looking at the,

basically the wobble of
Mars to help understand

what the core size may be in composition.

- The European Space
Agency is also well along

with ExoMars, a rover with
advanced drilling capability

due to be launched by 2018.

Its principle goal, to drill down deep

in search of microorganisms.

- What is new with ExoMars,
with the rover in particular,

is what we call the mobility.

Mobility, not only
horizontal, but also vertical.

This is a particular thing that we have

on board ExoMars mission,
so we will be able to sample

material from below the surface

that is quite important to understand

if there is any sign of a
past life activity on Mars.

- We will be looking, for the first time,

in the third dimension,

the third dimension being depth.

And we think that is where
we have the highest chance

of making an interesting discovery

regarding the presence of
organic molecules in Mars.

- It's a whole planet out there

with a complicated history.

It's that history is a story
that's stored in the rocks

and our job is to figure out that story

and what that story of that planet

tells us about this
planet that we live on.

- So where Curiosity takes
rocks and grinds them up

into powder and looks at
their bulk constituents,

what this mission would need
to do is be able to look

in a microscopic level
and examine the rocks

for these very tiny and detailed messages

that they would be sending to us

about the past life that
could've lived there.

- This that I'm holding up here

is a classic biosignature from the Earth,

it's a fossil.

We're not actually
expecting to see a fossil

of shells or other components,

but what we want to be able to see are,

with this instrumentation,

are the fine-scale layering
that one might see in a rock,

in which we can see dark
and light-toned layers.

And those dark and light tone
layers are telling a story.

- When will NASA send astronauts to Mars?

- Five, four, three,

two, one.

And lift off at dawn.

The dawn of Orion

and a new era of American
space exploration.

- The first test flight

of the Orion crew capsule is complete,

the hardware and systems are
ready for mass production.

The components, the
engineering, the manufacturing,

are all underway with NASA looking back

to what worked in the past

and utilizing it for the future.

- Fire.

- The solid rocket booster technology

straight from the space shuttle

has been extended and tested.

NASA's new Space Launch System, or SLS,

is coming closer to fruition,

reusing the space shuttle's main engines

as the new system's work horses,

saving billions of dollars

and years in research and development.

The Europeans are teaming up with NASA

to provide the service model for Orion,

allowing for long duration,
deep space flights.

Autonomous Martian landing
systems are well advanced

and being tested.

Software and hardware are fully integrated

for both manned and
unmanned Martian landings

and when they get there.

- Desert RAT stands for

Desert Research and Technology studies.

This is a group of
engineers and scientists.

- We're looking to test out new concepts,

procedures, equipment,
like rover concepts,

to see how they work in
the field environment.

- So the team tests these technologies

to make sure that in future
human space flight missions

we'll be able to do
science as best as we can.

That's something that NASA's never done,

two human rovers at the same time.

So we're really trying to develop

how do you use these
assets at the same time?

And interesting things that
you might not think about

are your communications.

So you potentially have
four astronauts talking

all at the same time to Mission Control

or science communication backroom.

- It's just like planning
a real mission, say

like you kind of think about
Apollo missions.

You had the astronauts on the moon

and you had people, Mission Control,

but there was a science
backroom you didn't hear about

but the astronauts were
getting information from them.

- Arizona has a very good climate

for these types of analog studies.

You have pretty much open
plains and you have a lot

of geological features that are analogous

to places on the moon and on Mars.

- Long-term space voyages are
being replicated on the ground

and in orbit with the ISS.

Surface habitats, power systems,

food and oxygen supply manufacturing,

are also on the drawing board.

- The human flight
component would like to see

an experiment where resources
on the surfaces of Mars

from the rocks or the
atmosphere could be used

to generate fuel or other parts

that would enable future exploration

in cutting the tie, so to speak, to Earth.

So you wouldn't necessarily have to bring

everything with you.

You can actually
manufacture it on the planet

and that's a really exciting
additional component

that we've been exploring and analyzing

in this work.

- NASA isn't the only one
with its eye on this prize.

ESA and now the Indian
Space Research Organization

have a spacecraft orbiting Mars

and they did it on their first attempt.

Private enterprise is
hard at work as well.

Mars 500, Mars One, The Mars Society,

Mars Foundation, and the Mars
Initiative, to name a few.

And they have volunteers lining up already

for a one-way trip to Mars.

It is inevitable that
we will set foot on Mars

in the very near future.

We will stay and learn her secrets.

Perhaps in the future

we will be able to alter
the atmospheric density

through terraforming and return Mars

to the world that it once was,

awash with oceans and
rivers, clouds and rain.

Maybe some of us could call it home.