This is such an awesome experience to get up close and personal with the Curiosity Rover
I mean this isn't the exact one that's on Mars obviously
but is basically identical
I'm here at Jet Propulsion lab in Pasadena the California
Oh How we got in here so it's amazing
This is the NASA center that's famous for building things
like the Mars rover, space probes and rescuing Matt Damon from the Red Planet
You guys must get pretty sick of answering questions about the Martian
Yes This is project scientist Ken Farley
I spoke with him about life on Mars
He's one of many scientists working on the first NASA mission in 40 years
designed specifically to look for life on another planet
It's called Mars 2020
If there were life on Mars wouldn't we have found it by now
No we would not have found it by now
We've been looking
There's been a number of missions
like the Viking landers and like curiosity for example
Part of the problem is we're not even sure what we're looking for
Life on Mars may have been completely different from life on Earth
Earth recent missions like the curiosity and exploration Rovers
look for and found evidence of water, a key ingredient
Follow the water where was the water and when was the water
and then looking for habitability looking for places that could have supported life
Now we know enough about Mars can look for ancient life
instead of anything on the surface of Mars today
There is no life on the surface of Mars today
Most likely if there is life on Mars today
it would be underground underneath the ice caps
in places that are very very hard to investigate with
the sort of Rovers and Landers that we've sent so far so
We're talking like moles groundhog
Well microscopic bacterial moles
no not actual moles we're looking for we call them bio signatures
It's a pattern or a substance in the rocks that can only been formed by life
To find those bio signatures
the 2020 Rover is going to need cutting-edge technologies developed here at JPL
But for definitive proof of life they'll need drill samples
We need to take a core
It's about the size of a piece of chalk
We have to collect 37 tubes like this
That will ultimately be laid on the surface of Mars for possible return in the future
Mars 2020 is different from past missions
because now NASA will need to bring those samples back to earth
to test them for evidence of life
if they are brought back to earth
we will be able to use all sorts of different kinds of techniques
many of which have not yet even been invented
because nobody has been posed with this question
So in order to find life
we'll have to return those samples from Mars
something that's never been done before
and test those samples with techniques that haven't even been invented yet
so I had to ask how good do you think your chances are finding life
mmm I'd say they're poorer than even just because I remain skeptical
regardless we were worried about what the early history of the solar system is like
and that's the same environment the same solar system that Earth within when life is in heaven
if you want to understand the origin of life on earth
because that's the only place we know life exists
The rocks that recorded that are all gone
So in a way looking at Mars is like looking at a version of Earth frozen in time
right about when life would have sprung
that's I think the most exciting way to look at it
It's just unbelievable the stuff that is happening here is just so far beyond anything else
it's like what are you doing today
are you sitting in your cubicle are you working on your computer
These guys are working on a freaking machine in outer space on Mars
that is trying to discover life
this is cool
that was one of my field pieces from the Netflix show Bill Nye saves the world
on which I am a correspondent
if you haven't seen it you should check it out
but obviously because that show is for a broader audience
I don't get to go into the kind of crazy detail that I sometimes do on this channel
For example this image is the first ever beamed back from the Martian surface
it was taken by the Soviet Lander Mars 3 on December 2nd 1971
after becoming the first man-made object to make a soft landing on Mars
that Lander transmitted data back to earth for just 40 point five seconds before going quiet
and no one really knows what happened to it
but it might have had something to do with the huge dust storm
that was taking place at the time
now this is the first clear image sent back from the Martian surface
It was taken by the Viking one Lander on July 20th 1976
and one of the stated aims for that mission
was to try to find evidence of existing life on the Martian surface
and there was this experiment called the labeled release experiment
where a scoop of Martian soil was taken
and then a dilute solution of nutrients was added into that soil
but in those nutrients was the radioactive atom carbon-14
the idea was if you tried to detect the gases around the soil
if you detect some radioactive carbon dioxide
you know that the nutrients were broken down by something in the soil
presumably something that's living
what was remarkable about this experiment
was that it got a positive result
there were a few other experiments trying to detect life in other ways
and they failed to get a detection
but this one detected radioactive carbon dioxide
and what's even more impressive
was the Viking 2 Lander which tried the same experiments after the Viking 1 Lander
it also got the same positive result
so things were looking promising
but then about a week later
they tried to rerun the experiment
add a little bit more nutrients to the soil and see if you could get more co2
but they couldn't There was no additional co2 released
so based on these negative results and the negative results of the other experiments
most scientists have concluded that
there is no surviving life on the surface of Mars today
So how is the co2 produced in the first place
Well chemists suspect that very highly oxidizing chemical things like perchlorates
exist in the Martian soil and would have reacted with the nutrients
producing the co2 to start with
but once those chemicals are used up
well there's nothing for those nutrients to react with
and so we get no co2 the next time the nutrients are introduced
This story highlights just how difficult searching for life is
using only remote instruments
and that's why for Mars 2020 they're going to
create some rock samples that should be returned to earth
if only they can get the budget for another mission that will go back and pick up
The rover they're sending in 2020
we'll also have some new tools on board that will allow them to look at rocks
in finer detail than ever before
one tool called pixel will use x-ray spectrometry
to try to detect chemical elements with a spatial resolution that goes down to the size of
a grain of salt
Now what they be looking for are layered structures
similar to stromatolite found here on earth
Those are mineral deposits which
get built up by billions and billions of tiny organisms
So you're not really looking for fossils or for tiny little you know microbial evidence
We're looking for the structures
that they would have produced layered structures
that's how we know about the oldest life on Earth
and so it's logical to think that's how we might find out about this old life on Mars
And the job of finding evidence of past or current life on Mars
is made even more difficult by planetary protection
That's the principle whereby we should not introduce any life from Earth to these places
where we're studying like Mars
and that's completely understandable because
I mean the worst discovery of life we could make on Mars would be life
that we introduced there by our spacecraft
I mean certain organisms are really Hardy even in the vacuum of space and even when bombarded
by radiation
But due to this constraint spacecraft must be strenuously sterilized and also
they're restricted from landing near sites where we think there may be liquid water
I'm really looking forward to the results of the Mars 2020 mission
and hopefully a later mission where we actually go back and collect the samples that were placed there
but one thing that really struck me from my interview with Kim Farley was
when he said that Mars is really like a time capsule of the rocks
that Earth had when life evolved here
that's a way I'd never really thought about it before
but of course because of plate tectonics and all the weathering
that have taken place on earth
we don't have the rock record from when life was first evolving on this planet
and that makes Mars a really good place to look
not only for new forms of life
but also for an understanding of how life
on Earth may have begun why