 
[MUSIC PLAYING]
 
Mars is our next door neighbour.
And so the one massive,
resounding question
that obsesses me is,
does Mars have life?
 
For a long time
there's been this idea,
has there been liquid water?
If it's got liquid
water of course,
it's long been
understood that's one
of the prerequisites of life.
When we're exploring Mars,
we don't do it in person.
We don't send human
astronauts, at least not yet.
And we send our machines.
We send robotic explorers and
beam back all that information
back to us, so we can
piece it together and learn
as much as we can
about this other world.
So if you want to design
an instrument for Mars,
for operation on Mars,
there's some key things
which you have to bear in mind.
It needs to be low mass.
It needs to be
lightweight and compact.
Even just to launch mass
into low Earth orbit,
I believe it costs something
like 20,000 pounds per kilo.
If you want to
get the equivalent
mass to the surface of
Mars, it costs an awful lot
more than that.
It needs to be able to survive
the vibration of launch.
It needs to be able to survive
high radiation environments.
And an average
surface temperature
is something like
minus 60 degrees
centigrade, so you got to
operate Curiosity and all
these instruments under
these extreme conditions.
 
Obviously, it's nice to
see it as a challenge.
And it's amazing
what can be achieved.
You put it in the pointy
end of a massive firework,
launch into space where it
travels through the very
brutal and an
unforgiving environment,
and then arrives at an
incredibly high speed.
So you've got to go from 6
kilometres per second to 0
in 7 minutes, that's
the challenge, landing
this 1,000 kilogramme rover.
And not end up burying
your years of working
and your millions of
pounds worth of equipment
and hardware in
a smoking crater.
It was a bit of a
step into the unknown.
 
Touch down confirmed.
We're safe on Mars.
 
That's when the
exploration starts.
 
A sol is Mars for a day.
It's about 24 hours
and 37 minutes.
We have to get our instruments
up to a working temperature,
so we only work after 11:00
AM local time on Mars.
But if you want to get
the most out of your rover
and your science and engineering
team in the first 90 days
when don't know if
things are going to last,
then it's best to switch to
Mars time into the rhythm
that Curiosity
has to go through.
 
What that means in practise is
that every couple of weeks you
end up working at 2
o'clock in the morning.
But that was OK.
No one was complaining
because we had our fantastic
rover on Mars that
we were operating.
Some people got watches
made to run on Mars time.
So if you ever see anyone around
Pasadena with two watches on,
then you know they're working
on a recent Mars mission.
 
Since the 17th century and the
first telescopic observations
of Mars, we've got to
learn our neighbour,
this other world
much, much better.
 
We have high resolution
colour images.
We have stereo images so we
can get accurate distances
and elevations.
 
And we have chemical and
x-ray diffraction data.
So we take all those
different data sources,
work out what's been happening
on Mars from billions of years
ago right up to the present.
 
And then, we discuss
on the telephone
what we think of the data
and what we need to do next.
So we might decide well, that's
a really interesting outcrop.
Maybe there's some
sign of water there.
But we need to
get another image.
We need to get a high
resolution image.
Perhaps we need some
x-ray diffraction.
And we make a plan for next
day and a longer term plan.
Then, we make sure that we've
used an appropriate amount
of power and the data
resources are OK.
And then, we upload
it to the rover.
And so the cycle repeats.
 
I'm an astrobiologist,
and my thrill
is into looking into the
possibility of their being life
on Mars.
And we're not, obviously,
talking about little green men.
We're talking about
hardy, microbes
called bacterial lifeforms.
And then, that's going
to be hard to find.
And actually, one of
the bigger questions
is whether the
environment on Mars
was ever conducive, was
ever clement for life.
We need to look at
the rocks and see
under what processes
they formed.
And to do that, we use tricks
like x-ray diffraction.
So we take our sieved material,
for instance, from the drill,
and we put it onto a
little vibrating stage.
Vibrating this fine
grade material,
we make sure we got an even mix
of all the different minerals
and all their different
crystal orientations.
The CheMin instrument
takes a source
of x-rays focused
through a pinhole.
Then, we direct
it onto the stage.
A very narrow beam of x-ray.
It's almost like a torch
shinning not with visible light
you can see with your
eyes but x-ray light.
And you collect
the x-rays, which
have defracted
through your sample.
Focused onto a CCT,
bit like at the back
of your digital camera.
And what we get there are these
rings, called Debye rings,
and measure the radius of
those rings using something
called Bragg's Law--
so that's going back
to beginning of the
century-- allows
us to measure the spacing
between different layers
of atoms.
And that's the information.
It tells you what kind of
mineral or what kind of rock
you're looking at.
And on Mars, some
of the minerals,
it's about one nanometer.
That tells us it's clay.
It was this kind of stuff.
This is modellers
clay I've got here.
It's the kind of thing you might
play with and make things out
of.
It's a very commonplace
material on Earth,
but to find this on Mars
is absolutely mind-blowing.
This is clay that was formed
in an aqueous environment.
And so what Curiosity
had essentially found
was river mud, the
mud on the bottom
of what would have
been a babbling brook
billions of years ago on
an ancient Martian surface.
And the conditions
needed to make this clay
would have been not too
acidic, not too alkaline, not
too salty.
And, in fact, if you
could have jumped
into a spaceship
and a time machine
and gone back to that place
on the surface of Mars
billions of years
ago and knelt down
and scoped up some of
that water in a glass,
you could have drunken
that Martian river water.
It's only really
because of Curiosity
that we know we've had these
long-standing bodies of water,
lakes, which lasted
for thousands of years.
 
The same technique that solved
the structure for salt in 1914
is being used today to
help in the search for life
on other worlds.
I don't suppose
they could possibly
have imagined that
x-ray diffraction would
be used on Mars.
But it shows just how important
the work was that they did.
With all of this
space exploration
and trying to get to
know other worlds,
you're obviously always
trying to push back
the very frontiers of
what we know already
and what we've been able
to achieve in the past.
And you can't always
play it too safe,
and you have got to take risks.
You've got very little
chance, or no chance at all,
of being able to repair
an instrument which
isn't working properly.
The answer to this is
really lots of testing.
 
You have this building
accumulation of knowledge.
And this helps us decide
the most exciting places
we want to go to next time.
Mars 2020 is an
interesting mission
because that is likely to be
the first part of Mars sample
return that we can take back to
Earth to do all sorts of tests
for presence or past
presence of life.
 
For me, I think having
mankind in space
is about the spirit
of exploration.
There really is an
awful lot that you
can do with machines
like Curiosity.
I think that, in the
end, you have to do both.
And, ok, you can get instruments
to the surface of Mars
at significantly less cost,
but, ultimately, there's
a limit to what you can
really do with machines alone.
And sending man there, you'd
have so much more flexibility.
And you can make decisions
right there and then
with a trained eye.
And I think that opens up
massive possibilities in terms
of science that you can do.
I would love to go.
But, yes, I'm probably
not young enough anymore.
 
it'd be a really
major challenge just
for these people to survive.
And that could happen
as early as the 2020s.
So there are
possibilities there.
In terms of a space agency
sending people there,
then they're going to
want to bring them back.
And 2030s is
probably the earliest
that that could
realistically happen.
So if you'd been a microbe on
Mars four billion years ago,
yeah, it would have
been habitable for you.
We don't yet know
if there were any.
Whether it did support
life is the next stage.
To think of the
cosmos as a whole,
and there are grand questions
to which we, at the moment,
we don't really have
much idea about.
So, for example, things like
why is the universe here
and how did it originate and--
OK, there is a simple answer
if it originated
in the Big Bang.
But, why did the Big Bang occur?
And, of course, day
to day, I'm working
on much more mundane things.
But, in many ways,
those are the things
which ultimately motivate
me to work in space science.
My long-term hope
is we get closer
to finding life on another
world because I think
that would be one of the most
fundamental and revolutionary
discoveries that we
could make as a species.
We know that we're not
alone in this universe.
It is necessary to
put in big effort
to get some worthwhile
harvest of knowledge.
You have to be prepared
to go a long distance .
Of course, we went a
very long distance,
over 60 million
kilometres to Mars,
and used a lot of resources,
both financial and manpower,
but I'm confidant it's
all been worth it.
 
