Original subtitles

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, is 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

searched 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 to it and where it is now? Thanks to the

specific instrumentation on board the mission, we were 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 objectives 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 the 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, aero braking 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 releases 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 the end 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, the sort of

signatures of past life that we would be looking

for would be signatures of microbial life.

Orbiters including Mars Odyssey and Mars Express

have been hunting down life as well from orbit.

After 10 years of mission, we have achieved a global view of

Mars, and then we know at every location on the surface if

you find some special minerals or not. So we have really the

global view that tells us the history of Mars. Mars Express

has for the first time detected methane, and also the

concentration in the atmosphere vary from a place to

another, from a season to another. And this discovery has

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. Methane has been

found previously in the Martian atmosphere by both Earth

-based telescopes and space-borne 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. 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 principal

areas are first by analogy with the Earth. It could be

released and produced 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 state 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 we're finding are biological or non-biological in

origin. There are several viable non-biological explanations

including this organic material could have 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 liftoff 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 ten

months later.

MAVEN is the Mars Atmosphere and Volatile Evolution Mission.

Our goal is to study the role that loss 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 is 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 used the world's three major 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, we have some indications that water was

flowing on the surface, but how much water was there? We're

talking about oceans, we're talking about small rivers,

little rain. So these definitions of how much water was on

the planet was very undefined. A major question has been how

much water didn't 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 the average

depth of the Mediterranean Sea. By combining Martian

topography with a new estimate for water loss, the

researchers were able to simulate Mars' 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 one and a half billion years, already much

longer than the period of time needed for life to develop

on Earth. And now we see that Mars must have been wet for a

period even longer. It's fascinating that we can learn so

much about 4.5 billion years ago when measurements are taken

right now. And ultimately we can conclude this idea of an

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. We're

putting two instruments on the surface and then we're

leaving them there. With no ground-in-the-loop interaction,

repetitive weekly uplink-downlink sessions, we're just made

to do this mission. The InSight mission is a geophysical

mission to Mars. It's going to go to Mars and take its

vital signs. It's going to take its heartbeat, the seismic

activity of the planet. So we're going to 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. It's going to take

its temperature by measuring the thermal gradient of the

surface, which tells how much heat is coming out. We also

have a heat flow probe. We call it HP cubed. And what that

does is it's going to basically take the temperature of Mars

and from that it will be able to understand what the thermal

flux is over the course of a full Martian year. And it's

going to sort of measure its reflexes by looking at how the

rotation wobbles with the tile effects of the sun. Our final

experiment is called RISE, and that's going to be looking at

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 principal 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. And this is a peculiar thing that we have

on board the 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 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 have 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 or 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 toned layers are

telling a story. When will NASA send astronauts to Mars?

Five, four, three, two, one, and liftoff 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.

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

workhorses, 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... The NASA RATS 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 to 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 background.

It's just like running a real mission, say, like the Apollo

mission to the moon. You had the astronauts on the moon, you

had the people mission control, but there was a science

background you didn't hear about, but the astronauts were

getting information from you. Arizona has a very good

climate for these types of analog studies. You have pretty

much open planes 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 surface 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 ties, 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 or 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 enterprises hard at work as well. Mars 500, Mars 1,

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.