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Language: en
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woo 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
it's basically identical I'm here at the
jet propulsion lab in Pasadena
California I don't know how we got in
here bill it's amazing this is the NASA
Center that's famous for building things
like the Mars rover space probe 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 but we've been looking there's
been a number of missions like the vik
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 to 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 ground hogs 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 have been
formed by life to find those bio
signatures the 2020 Rover is going to
need cuttingedge technologies developed
here at
JPL but for definitive Proof of Life
they'll need drill samples we need to
take a core that'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 at finding
life I'd say they're poorer than even
just because I remain skeptical
regardless we will learn about what the
early history of the solar system is
like and that's the same environment the
same solar system that Earth was in when
life was evolving if you want to
understand the origin of life on Earth
cuz 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 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 NY 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 Brad 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 14.5 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 experiment
after the Viking one 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
to day so how is the CO2 produced in the
first place well chemists suspect that
very highly oxidizing chemicals 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 them up but the Rover
they're sending in 2020 will 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
stromatolites 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 where
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 Ken 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
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