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Hi, I'm Lee and this is NASA Now.
Question for ya, What's your ideal environment?
Sunny. 72 degrees.
Light breeze.
How about living in a place that's
so dry it only gets rain once every 10 years.
Can life even exist?
We're gonna take you there.
And searching for life on Mars,
a stunning discovery by NASA Scientists.
That's ahead.
But first, here's what's happening at NASA Now.
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We're just a couple of weeks away from the launch
of Space Shuttle Endeavour.
In the meantime it was a successful
and final 39th mission for Space Shuttle Discovery.
Back on Earth now, the STS-133 crew members delivered important
spare parts to the International Space Station,
along with Robonaut 2, the first humanoid robot to work in space.
The orbiter Discovery will soon be making its way
to the Smithsonian, where people can have an up close
and personal look at this amazing
technological achievement.
Now let's take a look at the past.
And lift off.
June 10, 2003, NASA launched Spirit,
one of two Mars exploration rovers to launch that summer.
On January 3, 2004, after traveling a distance
of 487,000,000 kilometers, that's 302.6 million miles,
Spirit landed on Mars.
Only 3 hours after landing,
Spirit began returning its first pictures from the surface
of the fourth planet from the Sun.
Searching for life on Mars, it's a mission
for NASA Scientists Doctor Alfonso Davila
and Doctor Margarita Marinova from NASA Ames Research Center
in Northern California.
They're here to share some fascinating findings.
>> My name is Margarita Marinova.
>> My name is Alfonso Davila.
>> I'm currently working on trying
to understand the high elevation dry valleys in Antarctica.
>> And I do work in a extreme environment on Earth,
which I considered the analog [phonetic] to Mars.
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>> We really try to understand extreme environments.
And a lot of that relates to what we see on Mars.
>> Mars is a very extreme dry and cold desert.
And so on Earth we search for places which are like mars,
so we can understand how life can survive in this conditions.
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The driest deserts on Earth is in Chile.
It's called the Atacama Desert.
It never rains.
Any microorganism in the soil doesn't have access
to any liquid water.
>> The Antarctica is very cold, it is very dry.
And then through that we can really go to a place like Mars
and say, when was the last time that there could have been life
on Mars given what we know from the limits of life on Earth?
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>> As far as we know organisms really need water
in order to survive.
But we really look, there are definitely places
where there's no obvious water.
There are no rivers.
There are no lakes.
But there's still organisms living there.
So for example, one thing that we found is that even
at freezing temperatures, organisms can use the edges
of ice as effectively liquid.
Another example, actually in sandstones,
especially in Antarctica,
is that they'll live inside the rock.
There's actually enough room between the grains of sand
that they'll live in there.
And it's warmer, there's some moisture.
>> The place we found lots of life in Atacama, microbial life,
was the interior of salt.
Inside this salt we find large numbers of microorganisms.
Creating microorganisms, which are called photosynthetic,
because they use the light of the sun to make up their food.
It turns out that salt in the Atacama provides
that which is most important for life, and would just,
not found in the Atacama, which is liquid water.
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>> By actually measuring the chemistry in the environment,
measuring how much moisture is available,
even just as water vapor in that environment,
we can bracket the conditions
under which these organisms can survive.
>> We know that Mars has been dry for a very long time.
We know that there was water early in the beginning of,
in the history of the planet, but not it's completely dry.
What you see here is a picture of Mars.
The wide deposits where you have the large impact craters,
these has been with, by satellite they have shown
that these deposits contain chloride.
Chloride is one of the components of Halite.
[phonetic] Salt they used to call Halite,
and it's exactly the same salt we put in our food.
It's been suggested that this is actually an ancient lakebed,
and what you see on the surface are the evaporated salt.
The same; exactly same situation we have in the Atacama.
>> And so we're trying
to understand what the organisms really need to survive.
>> Like strategies.
Can a microorganism develop to survive
when conditions become so dry?
>> And so we can really get a very in-depth understanding
of what's happening in these areas:
What conditions are there?
How do they affect it?
And then from that knowledge we can take it
and apply it to Mars.
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>> If you want to bring more insight and the excitement
of discovery into your classroom, be sure to check
out the Fingerprints of Life Education Content Module
on the NASA Explorer Schools virtual campus.
>> In this content module you can get students
to answer the question, How is the temperature
of an organisms environment related
to its growth and survival?
>> Well that's it for NASA Now.
Be sure to tune in next week when its all systems go
for Space Shuttle Endeavor, NASA's next mission, STS 134.
We'll see you then on NASA Now.
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>> NASA Now comes to you from the virtual campus
at NASA Explorer Schools.