[Music]
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 the
Jet Propulsion lab in Pasadena
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 recent missions like the curiosity
and exploration Rovers look for and
found evidence of water a key ingredient
for life 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's 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
okay 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 the 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
[Music]
you