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(tense music)
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- [Narrator] An international armada
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of science probes is converging on Mars.
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(loud rumbling)
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00:00:10,830 --> 00:00:14,142
They are searching for
evidence of past life
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(forceful air blowing)
(resonant rumbling)
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while testing technologies needed
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for humans to safely
visit this desolate world.
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The Red Planet has beckoned generations
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of dreamers and space flight pioneers
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to imagine crossing the
wide gulf between worlds.
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Longstanding questions
hang in the balance.
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What is humanity's future in space?
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Could we actually make a second home
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on Mars?
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(tense music)
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Mission planners have long known
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it is nearly impossible to land on Mars.
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(deep rumbling)
(forceful air blowing)
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The atmosphere is thick
enough to melt spacecraft,
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which hit it going more than
16,000 kilometers an hour,
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yet it's so thin
(wind blowing)
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even a wide aero shell
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(loud thudding)
(wind blowing)
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plus a big parachute...
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- [Mission controller]
The parachute has deployed
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and we are seeing
significant deceleration.
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- [Narrator] Aren't enough
to fully break the fall.
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(loud thudding)
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- [Mission controller] Heat shield's up.
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- [Mission controller]
Perseverance has now slowed
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to subsonic speeds.
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(forceful wind blowing)
(loud clanging)
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(air swooshing)
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- [Narrator] Percy, the
Mars 2020 Perseverance rover
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used an innovative system of rockets
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(forceful air blowing)
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and an ingenious sky crane...
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- [Mission controller] Sky
crane maneuver has started.
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(forceful air blowing)
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- [Narrator] To gently touch down.
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- [Mission controller] Tango delta.
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- [Mission controller]
Touchdown confirmed.
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Perseverance safely on
the surface of Mars.
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(NASA crew cheering)
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- [Narrator] But exactly
how to land a crew
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of astronauts safely is a
problem waiting to be solved.
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Percy is among the most sophisticated
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mobile machines ever made.
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It's small companion, Ingenuity,
is the ultimate drone,
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testing for the first time
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controlled flight
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on another world.
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From the striking images Percy
and other probes send down,
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it's easy to believe Mars
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is very much like the deserts of Earth.
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(tranquil music)
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For at least a century,
visionaries have imagined,
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if we could just get there,
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it shouldn't be too tough
to explore in person
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to pioneer a frontier of
freedom and prosperity,
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and perhaps to make a backup
copy of Earth's biosphere
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in case of disaster.
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But the real Red Planet is a trickster
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with a long history of fooling us,
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colder than Antarctica,
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bone dry,
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harsh, toxic grit under foot,
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and a constant rain of
lethal radiation from above
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a tragic world.
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The Mars we wish for
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has never been the Mars that truly is.
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For thousands of years,
the bright Amber planet
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has been toying with human imagination.
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As they orbit,
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Earth and Mars come closest
together every 780 days or so.
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Called a planetary opposition,
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it's the best time to
observe the Red Planet,
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which over a few weeks
appears to slow down,
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backtrack,
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then speed forward again.
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Puzzled by this capricious
retrograde motion,
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Egyptian sky watchers saw Mars
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as a hawk-headed humanoid deity,
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flying back and forth between
the realms of the living
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and the dead.
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From its odd motion,
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Babylonian astrologers believe Mars
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to be a quick, impulsive, volatile god.
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On May 4th,
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357 BCE,
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the Greek natural philosopher Aristotle
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observed the half full moon passing
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in front of the Red Planet
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and realized that Mars must
be farther away than the moon,
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but he would have been
surprised by how much.
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Mars is about 200 times more distant.
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(forceful air blowing)
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Chemical rockets that take
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around three days to get to the moon
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would take nearly seven
months to reach Mars.
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(suspenseful music)
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Future nuclear thermal rockets
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might cut that trip to
less than three months.
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(suspenseful music)
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That's still a very long time
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to spend confined in a small spacecraft
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(suspenseful music)
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and you can't just return
home in a few hours or days
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if there's a problem.
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(suspenseful music)
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Astronauts in microgravity
must exercise often.
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(fast-paced music)
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Bones become brittle.
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Heart muscles get lazy.
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And about one-third Earth's gravity,
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how will Mars affect human
health over the long-term?
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(fast-paced music)
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Around 150 AD,
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Greek mathematician and
astrologer, Claudius Ptolemy,
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proposed at Mars and the
other four wandering stars
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must circle Earth on a set of spheres,
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but
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700 years later,
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Islamic astronomers began to find problems
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with Ptolemy's so-called epicycles.
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In 1543,
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Copernicus of Poland put the
sun at the center of motion
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and Mars looping behavior
finally made sense.
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(tranquil music)
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About 40 years later,
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wealthy, obsessive Danish
astronomer Tycho Brahe
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wanted to accept Copernicus geometry,
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but he couldn't quite let go of Ptolemy.
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Tycho insisted that the
immensely heavy Earth
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must be too lazy to orbit,
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(tranquil music)
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but massive worlds do move.
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In the early solar system
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the huge planet Jupiter may have migrated
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inward toward the sun,
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about as far as Mars' present day orbit.
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(energetic music)
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Plowing through the solar nebula,
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Jupiter gobbled up much
of the dust and gas,
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robbing Mars of its
potential to grow larger.
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The stunted planet could attain
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only about half Earth's diameter
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and barely 11% its mass.
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As Jupiter and Saturn
continued to migrate,
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they displaced billions
of tons of icy rocks,
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flinging them inward,
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(ambient music)
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a deluge of debris lasting
three million years,
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the late heavy bombardment.
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Today, the high country of
Mars' southern hemisphere
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has one very large hole punched in it,
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the Hellas Basin,
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the third largest impact
crater in the solar system,
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but the little planet may have been hit
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by something even bigger.
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As you fly from south to north,
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Mars' terrain sinks.
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From red and orange highlands
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down to green and blue valleys,
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Mars whole northern hemisphere
is a giant sunken ellipse
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draping over 40% of the planet.
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If this is an impact site,
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the incoming object would have been
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about the size of dwarf planet Pluto.
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(loud rumbling)
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It would have totally remade Mars,
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probably shutting off its internal dynamo,
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erasing its protective magnetic field
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and killing the chances for
a life-sustaining atmosphere.
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When groups of would-be
settlers do set sail for Mars,
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they must accept that
they will never again
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take a breath outside
their helmets or habitats.
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They will have spent
months crossing the void
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to a desolate world
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with a lethal environment.
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In September of 1610,
Galileo Galilei recorded
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the first telescopic observation of Mars.
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26 years later,
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Francisco Fontana made the first
known drawing of the planet
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saying it looked like a very black pill.
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By 1649,
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the Dutch brothers Christiaan
and Constantijn Huygens
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had developed much better optics.
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Christiaan sketched an
irregular mark on Mars.
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Living in the wetlands of Holland,
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he thought it looked like a big bog.
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So it became known as the Great Marsh,
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Syrtis Major.
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Huygens timed that rotating feature,
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finding the day length
on Mars to be like Earth.
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Seven years later,
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Giovanni Domenico Cassini
refined that figure
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to 24 hours plus 40 minutes,
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very close to what
astronomers measure today.
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Cassini also logged the first observation
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of Mars' south polar cap.
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Watching the changing faces of Mars,
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Cassini imagined it must
be quite similar to Earth.
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(tense music)
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Three billion years ago,
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Mars may indeed have been Earth-like,
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volcanoes building the atmosphere,
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(water flowing)
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steam and mist and flowing
water filling early seas
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with more fluid than the
Arctic ocean on Earth.
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In 1997,
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00:12:19,890 --> 00:12:23,380
Sojourner, NASA's first Mars rover,
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found the outflow of a cataclysmic flood.
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00:12:26,145 --> 00:12:28,645
(tense music)
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00:12:35,390 --> 00:12:37,540
Beginning in 2004,
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the Mars exploration rovers
Spirit and Opportunity
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found stacked strata of rock
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laid down by flowing water
over thousands of years
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and little rounded iron-rich concretions
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nicknamed blueberries that
must've formed in pockets of silt
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lying under salty water.
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But what of water on modern Mars?
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NASA's Phoenix found evidence in 2008.
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(forceful air blowing)
(loud scraping)
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Soft landing at a high northern latitude,
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its rocket plumes blew away surface dust,
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00:13:15,380 --> 00:13:17,513
exposing some white material.
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Digging a shallow trench, the
little probe revealed more,
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which disappeared within a day.
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And on the lander's legs
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drops of liquid appeared,
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00:13:34,850 --> 00:13:36,103
then changed.
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(soft rattling)
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In August of 2012,
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the Mars Science lab,
Curiosity, began to roll,
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trekking through dry stream beds
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between the banks of ancient watercourses
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00:13:52,630 --> 00:13:54,420
and across the alluvial fan
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at the mouth of a long dead river.
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00:14:02,120 --> 00:14:06,010
Perseverance joined Curiosity in 2021.
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Landing in a once-flooded crater,
243
00:14:08,590 --> 00:14:12,083
finding the clay-rich rocks
of an ancient river delta,
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00:14:14,020 --> 00:14:17,860
these hardy robot geologists
found layered terrains
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each built by episodes of flowing mud
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with dry times in between,
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but these wet periods ended long ago.
248
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Today's Mars seems a lifeless desert,
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(soft rattling)
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a lonely landscape
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crying out for company.
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In 1698,
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00:14:49,950 --> 00:14:53,370
Christiaan Huygens did not
think Mars was so desolate.
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00:14:53,370 --> 00:14:54,527
His last book,
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"Cosmotheoros"
256
00:14:56,110 --> 00:14:58,570
imagined that the worlds
of the solar system
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must harbor plants and animals.
258
00:15:01,450 --> 00:15:03,930
Though they would be
different from those on Earth,
259
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they probably led comparable lives.
260
00:15:06,740 --> 00:15:09,550
Huygens saw no reason
that life on the planets
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should not be intelligent.
262
00:15:12,200 --> 00:15:13,500
And he also pointed out
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how important water would
be to those creatures.
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(tranquil music)
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The moon is rich in aluminum, titanium,
266
00:15:24,170 --> 00:15:25,973
silicon and magnesium.
267
00:15:28,670 --> 00:15:30,830
Asteroids add carbon, cobalt,
268
00:15:30,830 --> 00:15:34,113
platinum, molybdenum,
nickel, and other elements.
269
00:15:36,230 --> 00:15:38,090
Mars has all of these,
270
00:15:38,090 --> 00:15:40,670
plus abundant iron and other metals,
271
00:15:40,670 --> 00:15:43,223
especially near its enormous volcanoes,
272
00:15:45,480 --> 00:15:49,000
but Mars' key ingredient is water ice,
273
00:15:49,000 --> 00:15:52,120
which can be split to
make breathable oxygen
274
00:15:52,120 --> 00:15:53,393
and hydrogen fuel.
275
00:15:55,200 --> 00:15:58,610
Percy is testing this idea right now,
276
00:15:58,610 --> 00:16:00,720
breathing in carbon dioxide
277
00:16:00,720 --> 00:16:03,513
and electrochemically
breaking out the oxygen.
278
00:16:05,320 --> 00:16:07,090
Water from beneath the surface
279
00:16:07,090 --> 00:16:09,510
plus carbon dioxide from its atmosphere
280
00:16:09,510 --> 00:16:12,803
can be rearranged to
make methane and oxygen.
281
00:16:14,170 --> 00:16:16,550
Use that oxygen to burn the methane,
282
00:16:16,550 --> 00:16:17,825
and you can launch rockets.
283
00:16:17,825 --> 00:16:20,850
(forceful air blowing)
284
00:16:20,850 --> 00:16:23,000
By making propellant on Mars,
285
00:16:23,000 --> 00:16:25,550
the cost of getting back to Earth drops
286
00:16:25,550 --> 00:16:27,293
by at least a factor of five.
287
00:16:29,890 --> 00:16:32,840
To conjure up space-based civilization,
288
00:16:32,840 --> 00:16:36,130
we can bring with us
only tools and talent,
289
00:16:36,130 --> 00:16:39,150
small factories and power generators.
290
00:16:39,150 --> 00:16:41,638
We must hunt and gather the rest.
291
00:16:41,638 --> 00:16:44,305
(ambient music)
292
00:16:46,620 --> 00:16:48,219
In 1704,
293
00:16:48,219 --> 00:16:50,250
Giacomo Filippo Maraldi
294
00:16:50,250 --> 00:16:53,080
guessed that dark rings around Mars poles
295
00:16:53,080 --> 00:16:55,410
might be melt lines.
296
00:16:55,410 --> 00:16:57,853
Could the poles be ice caps, he wondered.
297
00:16:59,930 --> 00:17:03,367
80 years later, Frederick
William Herschel declared,
298
00:17:03,367 --> 00:17:06,900
"Yes, Mars poles are water ice."
299
00:17:06,900 --> 00:17:10,190
And he thought that the
broad dark equatorial patches
300
00:17:10,190 --> 00:17:12,090
must be oceans.
301
00:17:12,090 --> 00:17:14,680
Herschel daydreamed what it might be like
302
00:17:14,680 --> 00:17:16,363
to sail those waters.
303
00:17:19,035 --> 00:17:21,785
(tranquil music)
304
00:17:23,630 --> 00:17:27,310
Mars probably lost its
oceans before life emerged
305
00:17:27,310 --> 00:17:28,863
out of the seas on Earth.
306
00:17:31,110 --> 00:17:32,910
The northern desert lowlands,
307
00:17:32,910 --> 00:17:36,030
the flattest topography
on any known planet,
308
00:17:36,030 --> 00:17:38,393
look like the floor of an ancient sea.
309
00:17:40,750 --> 00:17:42,530
Up to four kilometers deep,
310
00:17:42,530 --> 00:17:46,683
Mars' polar ocean may have
covered a third of the planet.
311
00:17:50,070 --> 00:17:51,610
In 1785,
312
00:17:51,610 --> 00:17:54,010
Herschel speculated that Martians
313
00:17:54,010 --> 00:17:57,173
probably enjoy a situation
similar to our own,
314
00:17:58,230 --> 00:18:02,193
but he realized the Martian
atmosphere must be very thin.
315
00:18:05,340 --> 00:18:06,463
It is thin.
316
00:18:07,340 --> 00:18:10,623
The planet is enveloped
in sparse carbon dioxide.
317
00:18:11,550 --> 00:18:13,663
There's very little water in the air,
318
00:18:14,800 --> 00:18:16,770
but there is methane
319
00:18:16,770 --> 00:18:20,253
which could be coming from
hot underground geology,
320
00:18:22,680 --> 00:18:25,600
but the methane levels
sometimes rapidly blooms
321
00:18:26,480 --> 00:18:28,303
then quickly disappears.
322
00:18:29,440 --> 00:18:32,460
And that has a lot of experts wondering,
323
00:18:32,460 --> 00:18:35,743
might something be
living below the surface?
324
00:18:41,690 --> 00:18:43,050
In 1788,
325
00:18:43,050 --> 00:18:45,093
Johann Hieronymus Schroeter proposed
326
00:18:45,093 --> 00:18:48,830
that Mars has no solid surface at all,
327
00:18:48,830 --> 00:18:51,283
just drifting clouds and misty rain,
328
00:18:53,580 --> 00:18:56,730
but Schroeter's shifting
scene was probably just due
329
00:18:56,730 --> 00:19:00,303
to the unstable air of Earth
above his big telescope.
330
00:19:04,250 --> 00:19:08,252
The true story of Mars
atmosphere is becoming clearer.
331
00:19:08,252 --> 00:19:10,300
(tense music)
332
00:19:10,300 --> 00:19:13,460
Going back at least a billion years,
333
00:19:13,460 --> 00:19:16,770
intense ultraviolet radiation from the sun
334
00:19:16,770 --> 00:19:20,353
and the sputtering solar wind
bombarded the small planet.
335
00:19:21,590 --> 00:19:26,280
With its low gravity and
frail global magnetic field,
336
00:19:26,280 --> 00:19:29,743
Mars could not hold on to
its protective gas envelope.
337
00:19:32,280 --> 00:19:34,640
Most of its air was lost to space
338
00:19:36,100 --> 00:19:39,683
and the rest of its water
absorbed into the ground.
339
00:19:43,120 --> 00:19:44,690
Back in 1830,
340
00:19:44,690 --> 00:19:47,413
none of this dreadful history was known.
341
00:19:48,700 --> 00:19:51,520
Johann Heinrich Madler and Wilhelm Beer
342
00:19:51,520 --> 00:19:54,183
crafted the first fairly
accurate Mars maps.
343
00:19:56,550 --> 00:19:59,420
They placed their zero
longitude line through a feature
344
00:19:59,420 --> 00:20:02,830
that will later be named Sinus Meridiani,
345
00:20:02,830 --> 00:20:04,143
Meridian Bay.
346
00:20:07,670 --> 00:20:11,600
This is what Meridian bay
looks like from the ground.
347
00:20:11,600 --> 00:20:15,830
The Opportunity rover explored
it for 13 and a half years,
348
00:20:15,830 --> 00:20:19,323
sending home images of the
stark, withered land escape.
349
00:20:21,800 --> 00:20:25,440
It's easy to imagine
standing on Mars yourself,
350
00:20:25,440 --> 00:20:28,083
gazing at the intricately weathered rocks.
351
00:20:31,950 --> 00:20:34,800
Nearly everywhere our probes look,
352
00:20:34,800 --> 00:20:37,609
they see evidence of past liquid water.
353
00:20:37,609 --> 00:20:39,600
(tranquil music)
354
00:20:39,600 --> 00:20:42,110
Though there are no oceans today,
355
00:20:42,110 --> 00:20:44,053
there's plenty of hidden ice.
356
00:20:45,580 --> 00:20:49,980
The Mars reconnaissance orbiter
recorded eroded cliff faces
357
00:20:49,980 --> 00:20:52,550
exposing compacted, frozen water,
358
00:20:52,550 --> 00:20:56,022
in some places more than
a hundred meters thick.
359
00:20:56,022 --> 00:20:58,400
(tranquil music)
360
00:20:58,400 --> 00:21:00,410
On passes over the poles,
361
00:21:00,410 --> 00:21:04,233
MROs radar revealed up
to two kilometers of ice.
362
00:21:06,970 --> 00:21:09,123
It's been laid down in layers,
363
00:21:10,190 --> 00:21:13,000
suggesting that Mars climate may cycle
364
00:21:13,000 --> 00:21:14,910
between warm and cool times
365
00:21:20,230 --> 00:21:22,360
Zooming in from orbit,
366
00:21:22,360 --> 00:21:24,340
we can see dark streaks
367
00:21:24,340 --> 00:21:26,930
that appear and disappear seasonally
368
00:21:26,930 --> 00:21:28,903
on the slopes of steeper craters.
369
00:21:31,570 --> 00:21:34,483
They look a lot like desert
rain gullies on Earth,
370
00:21:36,240 --> 00:21:37,720
and many researchers thought
371
00:21:37,720 --> 00:21:40,023
they might be flowing salty water.
372
00:21:41,760 --> 00:21:45,523
New analysis suggests that the
larger ones at least are dry,
373
00:21:47,020 --> 00:21:50,770
streams of rounded sand grains
tumbling over one another
374
00:21:51,930 --> 00:21:54,943
flowing like liquid in
the low gravity of Mars,
375
00:21:57,830 --> 00:21:59,030
but the small ones
376
00:21:59,030 --> 00:22:00,463
seem truly wet.
377
00:22:05,040 --> 00:22:06,820
In 1862,
378
00:22:06,820 --> 00:22:08,810
astronomer Camille Flammarion
379
00:22:08,810 --> 00:22:11,490
picked up the idea of intelligent aliens,
380
00:22:11,490 --> 00:22:13,830
publishing the first of his eight books
381
00:22:13,830 --> 00:22:16,597
about life on the planets.
382
00:22:16,597 --> 00:22:18,960
"The Plurality of Inhabited Worlds"
383
00:22:18,960 --> 00:22:21,093
became an all-time bestseller.
384
00:22:22,420 --> 00:22:25,340
Charles Darwin's notion
that species develop
385
00:22:25,340 --> 00:22:27,230
in response to their environment
386
00:22:27,230 --> 00:22:30,550
led Flammarion to speculate
that various planets
387
00:22:30,550 --> 00:22:34,143
would cause creatures there
to be unlike those of Earth.
388
00:22:38,540 --> 00:22:40,270
Drilling into the rocks,
389
00:22:40,270 --> 00:22:43,360
Mars rovers have shown the
building blocks of life
390
00:22:43,360 --> 00:22:44,677
to be plentiful.
391
00:22:44,677 --> 00:22:47,610
(tranquil music)
392
00:22:47,610 --> 00:22:51,240
Clay minerals would have filtered
salts and harsh compounds
393
00:22:51,240 --> 00:22:53,103
from the primeval flowing waters.
394
00:22:54,340 --> 00:22:57,390
Many types of microbes now living on Earth
395
00:22:57,390 --> 00:23:00,373
almost surely could have
survived on ancient Mars,
396
00:23:02,880 --> 00:23:04,270
but no photos,
397
00:23:04,270 --> 00:23:07,360
fossils or direct
chemical evidence of life
398
00:23:07,360 --> 00:23:08,643
have yet turned up.
399
00:23:12,990 --> 00:23:13,823
Around
400
00:23:13,823 --> 00:23:14,680
1864,
401
00:23:14,680 --> 00:23:16,480
the Vatican became concerned
402
00:23:16,480 --> 00:23:19,380
about the state of grace of the Martians.
403
00:23:19,380 --> 00:23:23,350
Father Pietro Angelo Secchi of
the Roman College Observatory
404
00:23:23,350 --> 00:23:25,303
began to chart where they might live.
405
00:23:26,140 --> 00:23:29,170
He renamed Huygens' Syrtis Major feature,
406
00:23:29,170 --> 00:23:31,623
calling it the Atlantic Canale.
407
00:23:32,570 --> 00:23:34,743
That word simply means channel.
408
00:23:35,870 --> 00:23:39,540
Secchi intended no reference
to intelligent design,
409
00:23:39,540 --> 00:23:41,330
but his term canale
410
00:23:41,330 --> 00:23:44,503
would cause much confusion
over the following years.
411
00:23:45,820 --> 00:23:47,640
At the same time, in England,
412
00:23:47,640 --> 00:23:51,910
astronomer William Dawes
made Mars maps of his own.
413
00:23:51,910 --> 00:23:54,150
Dawes was extremely nearsighted,
414
00:23:54,150 --> 00:23:57,403
but his charts were more
detailed than any before.
415
00:23:59,500 --> 00:24:01,430
Sensing a great story,
416
00:24:01,430 --> 00:24:04,010
science writer, Richard Anthony Proctor
417
00:24:04,010 --> 00:24:06,702
blasted the Dawes maps out to the public.
418
00:24:06,702 --> 00:24:09,702
(melancholic music)
419
00:24:11,460 --> 00:24:15,270
The Suez canal was completed
in November of 1869,
420
00:24:15,270 --> 00:24:17,203
making news around the world.
421
00:24:19,590 --> 00:24:23,020
The Panama canal was
in the planning stages
422
00:24:23,020 --> 00:24:25,810
and many people made a
connection between the straight
423
00:24:25,810 --> 00:24:27,990
canale on Mars maps
424
00:24:27,990 --> 00:24:30,783
and these great works
of engineering on Earth.
425
00:24:34,200 --> 00:24:38,020
There are many ancient water
channels all over Mars,
426
00:24:38,020 --> 00:24:41,303
but there's no evidence of
technology in their shapes.
427
00:24:44,660 --> 00:24:47,180
Mars came again into opposition
428
00:24:47,180 --> 00:24:48,593
in 1877.
429
00:24:49,630 --> 00:24:52,320
Nathaniel Green, an artist by day
430
00:24:52,320 --> 00:24:54,180
and astronomer by night,
431
00:24:54,180 --> 00:24:56,913
painted the most accurate Mars chart yet.
432
00:24:59,400 --> 00:25:00,660
Over in America,
433
00:25:00,660 --> 00:25:03,130
the self-taught astronomer, Asaph Hall,
434
00:25:03,130 --> 00:25:05,053
noticed something no one else had,
435
00:25:06,070 --> 00:25:08,740
two tiny moons.
436
00:25:08,740 --> 00:25:10,440
Phobos and Deimos
437
00:25:10,440 --> 00:25:12,110
may be bits of Mars
438
00:25:12,110 --> 00:25:16,210
flung into orbit by
giant impacts long ago,
439
00:25:16,210 --> 00:25:20,283
or they may be asteroids
captured by the planet's gravity.
440
00:25:22,280 --> 00:25:24,220
With Mars particularly close,
441
00:25:24,220 --> 00:25:27,470
within just 56 million
kilometers of Earth,
442
00:25:27,470 --> 00:25:30,363
Giovanni Schiaparelli began to map it.
443
00:25:31,586 --> 00:25:35,590
Though he, like Dawes, was
near-sighted and colorblind,
444
00:25:35,590 --> 00:25:38,650
Schiaparelli was somehow
able to extract more
445
00:25:38,650 --> 00:25:40,363
from the telescope than others.
446
00:25:43,140 --> 00:25:46,870
He too called the lines
he saw on Mars canale,
447
00:25:46,870 --> 00:25:49,690
giving them whimsical names
from classical literature
448
00:25:49,690 --> 00:25:51,233
that are still used today.
449
00:25:53,340 --> 00:25:56,143
Some Mars oppositions
are closer than others.
450
00:25:57,220 --> 00:26:00,660
While Earth's orbit around
the sun is nearly circular,
451
00:26:00,660 --> 00:26:03,230
Mars orbit is much more elliptical.
452
00:26:03,230 --> 00:26:06,130
(ambient music)
453
00:26:06,130 --> 00:26:08,620
During Mars southern autumn and winter,
454
00:26:08,620 --> 00:26:11,600
that hemisphere is
tipped away from the sun
455
00:26:11,600 --> 00:26:14,120
and the whole planet is farther away,
456
00:26:14,120 --> 00:26:17,718
making those seasons longer and colder.
457
00:26:17,718 --> 00:26:21,090
(ambient music)
458
00:26:21,090 --> 00:26:24,690
With the next close opposition, in 1879,
459
00:26:24,690 --> 00:26:26,470
Schiaparelli came to believe
460
00:26:26,470 --> 00:26:29,626
he was seeing pairs of straight canale.
461
00:26:29,626 --> 00:26:32,690
(ambient music)
462
00:26:32,690 --> 00:26:35,810
Harvard College Observatory's
William Henry Pickering
463
00:26:35,810 --> 00:26:39,010
declared that martian
canals were only visible
464
00:26:39,010 --> 00:26:42,077
because plants were
growing along their banks.
465
00:26:42,077 --> 00:26:44,744
(ambient music)
466
00:26:48,440 --> 00:26:51,320
All speculation about
large engineering projects
467
00:26:51,320 --> 00:26:52,950
by smart Martians
468
00:26:52,950 --> 00:26:54,250
was put to rest
469
00:26:54,250 --> 00:26:57,340
of the night of July 14th, 1965
470
00:26:57,340 --> 00:27:00,293
as NASA's Mariner 4 flew by Mars.
471
00:27:01,360 --> 00:27:03,630
In the probes' 21 images,
472
00:27:03,630 --> 00:27:06,873
Mars looked much more like
the moon than the Earth.
473
00:27:08,240 --> 00:27:09,200
Worse,
474
00:27:09,200 --> 00:27:12,193
Mariner couldn't find a
protective magnetic field.
475
00:27:13,730 --> 00:27:16,680
Harsh solar wind and cosmic radiation
476
00:27:16,680 --> 00:27:19,633
would have been scouring
the planet for millennia.
477
00:27:21,120 --> 00:27:24,290
It's tough to imagine
how even primitive life
478
00:27:24,290 --> 00:27:25,483
could survive here.
479
00:27:31,620 --> 00:27:33,330
But back in 1892,
480
00:27:33,330 --> 00:27:35,480
Camille Flammarion was still filling
481
00:27:35,480 --> 00:27:38,560
his imaginary Martian canals with water.
482
00:27:38,560 --> 00:27:41,910
He speculated they were the
rectification of old rivers
483
00:27:41,910 --> 00:27:43,500
by the inhabitants for the purpose
484
00:27:43,500 --> 00:27:45,610
of general water distribution
485
00:27:45,610 --> 00:27:47,990
and that the actual habitation of Mars
486
00:27:47,990 --> 00:27:51,363
by beings superior to
our own is very probable.
487
00:27:52,640 --> 00:27:55,770
Pouring more into Flammarion's
illusory waterworks,
488
00:27:55,770 --> 00:27:59,803
Pickering asserted that he
had observed up to 40 lakes.
489
00:28:01,230 --> 00:28:03,020
At about the same time,
490
00:28:03,020 --> 00:28:05,900
a wealthy world-traveling
American diplomat
491
00:28:05,900 --> 00:28:08,550
was feeling like he needed a career change
492
00:28:08,550 --> 00:28:10,513
and a personal passion project.
493
00:28:12,200 --> 00:28:15,250
Percival Lowell had
read Flammarion's books
494
00:28:15,250 --> 00:28:17,550
and he made plans to look for Martians
495
00:28:17,550 --> 00:28:20,423
during the coming opposition of 1894.
496
00:28:22,110 --> 00:28:24,410
Pickering helped lowering two telescopes
497
00:28:24,410 --> 00:28:26,633
on a hilltop in Flagstaff, Arizona.
498
00:28:27,670 --> 00:28:29,750
The new Lowell Observatory
499
00:28:29,750 --> 00:28:32,523
stared at Mars all summer long.
500
00:28:33,460 --> 00:28:35,890
But Lowell, an untrained observer,
501
00:28:35,890 --> 00:28:38,850
saw only what he believed.
502
00:28:38,850 --> 00:28:42,000
He sketched a planet-wide
irrigation system
503
00:28:42,000 --> 00:28:45,680
transporting billions of
gallons of melted polar snow
504
00:28:45,680 --> 00:28:48,310
to equatorial oases,
505
00:28:48,310 --> 00:28:52,253
the irrigated agriculture
projects of an advanced race.
506
00:28:56,050 --> 00:28:58,420
But during the same opposition,
507
00:28:58,420 --> 00:29:00,290
astronomer Edward Barnard,
508
00:29:00,290 --> 00:29:02,620
wielding the California Lick Observatory's
509
00:29:02,620 --> 00:29:04,420
larger refracting telescope,
510
00:29:04,420 --> 00:29:09,030
could not find a single
straight line anywhere on Mars.
511
00:29:09,030 --> 00:29:11,530
And when the Lick's William
Campbell examined Mars
512
00:29:11,530 --> 00:29:15,083
with a spectroscope, he
saw not a trace of water.
513
00:29:17,330 --> 00:29:19,510
English astronomer, Edward Maunder
514
00:29:19,510 --> 00:29:21,930
demonstrated how straight lines on Mars
515
00:29:21,930 --> 00:29:24,073
could easily be optical illusions.
516
00:29:27,910 --> 00:29:28,880
Undeterred,
517
00:29:28,880 --> 00:29:31,250
Percival Lowell sprinted across America
518
00:29:31,250 --> 00:29:33,400
on a lecture tour in 1895,
519
00:29:33,400 --> 00:29:36,717
promoting his book named simply "Mars".
520
00:29:38,540 --> 00:29:41,150
A story-thirsty public bought his tales
521
00:29:41,150 --> 00:29:43,853
of Martian waterworks by the thousands.
522
00:29:51,850 --> 00:29:54,443
The real Mars is a parched planet.
523
00:29:56,080 --> 00:29:59,293
Though tilted rocks tell us
there were lakes here long ago,
524
00:30:02,950 --> 00:30:06,473
today, dust devils swirl
across the barren terrain.
525
00:30:07,780 --> 00:30:10,100
The Spirit rover caught one in the act
526
00:30:10,100 --> 00:30:12,873
486 Martian days after landing.
527
00:30:15,450 --> 00:30:17,400
Curtains of desiccated grit
528
00:30:17,400 --> 00:30:21,083
sweep up into the hazy sky
from rugged canyon cliffs.
529
00:30:23,750 --> 00:30:27,780
Dry, sandy landslides
garnish steep crater walls
530
00:30:27,780 --> 00:30:29,513
and clump on the floors.
531
00:30:34,070 --> 00:30:35,630
Percival Lowell began observing
532
00:30:35,630 --> 00:30:39,280
with an even bigger refractor in 1896,
533
00:30:39,280 --> 00:30:42,023
but still could not see his glaring error.
534
00:30:43,350 --> 00:30:46,010
Lowell carried on for 20 more years,
535
00:30:46,010 --> 00:30:50,560
hallucinating over 450
canals with vegetation,
536
00:30:50,560 --> 00:30:54,100
seduced by the drama of
a desperate civilization
537
00:30:54,100 --> 00:30:57,030
bravely combating global climate change
538
00:30:57,030 --> 00:31:00,643
as their dying world dried
to a planetary desert.
539
00:31:03,055 --> 00:31:06,460
(ambient music)
540
00:31:06,460 --> 00:31:07,440
In fact,
541
00:31:07,440 --> 00:31:09,713
Mars' climate did change radically,
542
00:31:11,140 --> 00:31:13,433
but it happened long before Lowell's time.
543
00:31:15,920 --> 00:31:18,660
Without the large moon to stabilize it,
544
00:31:18,660 --> 00:31:20,630
Mars wobbles tens of degrees
545
00:31:20,630 --> 00:31:22,940
over hundreds of thousands of years,
546
00:31:22,940 --> 00:31:24,693
much more wildly than Earth.
547
00:31:27,360 --> 00:31:29,683
When Mars points a pole toward the sun,
548
00:31:31,040 --> 00:31:34,500
billions of tons of CO2 might be released,
549
00:31:34,500 --> 00:31:37,023
unleashing epics of greenhouse warming.
550
00:31:39,110 --> 00:31:41,690
This might melt some surface ice,
551
00:31:41,690 --> 00:31:43,473
letting the water flow,
552
00:31:43,473 --> 00:31:45,950
(tranquil music)
553
00:31:45,950 --> 00:31:47,620
but the temperate times
554
00:31:47,620 --> 00:31:49,121
can never last.
555
00:31:49,121 --> 00:31:51,871
(tranquil music)
556
00:31:52,790 --> 00:31:56,260
In his 1899 novel "The War of the Worlds,"
557
00:31:56,260 --> 00:31:59,693
H. G. Wells found drama
in the doomed planet.
558
00:32:02,040 --> 00:32:05,080
An advanced race of Martians
comes to conquer Earth
559
00:32:06,710 --> 00:32:09,627
and enslave humans as work animals.
560
00:32:09,627 --> 00:32:12,127
(tense music)
561
00:32:16,670 --> 00:32:18,470
In 1976,
562
00:32:18,470 --> 00:32:21,080
Earth sent two Viking landers,
563
00:32:21,080 --> 00:32:23,249
not to subjugate, but to investigate.
564
00:32:23,249 --> 00:32:24,457
- [Mission controller] Brace for dismount.
565
00:32:24,457 --> 00:32:25,540
- [Mission controller] ACS is green,
566
00:32:25,540 --> 00:32:28,110
1.5 degrees per second max, 0.2 Gs.
567
00:32:28,110 --> 00:32:29,077
- [Mission controller]
Eight feet per second.
568
00:32:29,077 --> 00:32:30,335
- [Mission controller]
Touchdown, we have touchdown.
569
00:32:30,335 --> 00:32:32,663
(NASA crew cheering)
570
00:32:32,663 --> 00:32:33,733
- [Mission controller] We have touchdown.
571
00:32:33,733 --> 00:32:35,280
(cheering drowns out speaker)
572
00:32:35,280 --> 00:32:36,820
- [Narrator] They found very active,
573
00:32:36,820 --> 00:32:38,533
intriguing surface chemistry,
574
00:32:39,440 --> 00:32:40,910
but evidently,
575
00:32:40,910 --> 00:32:41,743
no life.
576
00:32:46,210 --> 00:32:47,730
Back in 1905,
577
00:32:47,730 --> 00:32:49,550
the idea of a living Mars
578
00:32:49,550 --> 00:32:52,223
captured Lowell
Observatory's Carl Lampland.
579
00:32:53,420 --> 00:32:56,633
He claimed to have photographed 38 canals.
580
00:32:58,080 --> 00:33:00,130
Now, it's vital to remember,
581
00:33:00,130 --> 00:33:03,170
most of these observers
were good astronomers,
582
00:33:03,170 --> 00:33:05,970
wielding the best telescopes of their day,
583
00:33:05,970 --> 00:33:08,763
yet they saw what wasn't there,
584
00:33:09,690 --> 00:33:12,690
a lesson perhaps for those who, today,
585
00:33:12,690 --> 00:33:14,223
dream of settling Mars.
586
00:33:16,920 --> 00:33:20,260
In 1909, at the Meudon
Observatory near Paris,
587
00:33:20,260 --> 00:33:24,750
astronomer Eugene Antoniadi
could find no linear canals,
588
00:33:24,750 --> 00:33:26,710
yet the public had been seduced
589
00:33:26,710 --> 00:33:29,700
by the idea of an alien civilization.
590
00:33:29,700 --> 00:33:32,070
American novelist Edgar Rice Burroughs
591
00:33:32,070 --> 00:33:34,430
released the first of his 11-volume tale
592
00:33:34,430 --> 00:33:38,110
depicting heroic John
Carter on a fictional Mars,
593
00:33:38,110 --> 00:33:40,053
the desert planet Barsoom.
594
00:33:44,100 --> 00:33:47,453
Today's Mars rovers are
finding a desert world too.
595
00:33:51,540 --> 00:33:55,233
Curiosity trekked around a
wide field of dark sand dunes.
596
00:33:56,850 --> 00:33:59,110
Rolling like waves on an ocean,
597
00:33:59,110 --> 00:34:02,383
the Sandy mounds slowly
migrate across the terrain.
598
00:34:06,940 --> 00:34:10,520
The orbiting high-rise camera
caught Curiosity at work
599
00:34:10,520 --> 00:34:13,003
in what's known as the Bagnold Dune Sea.
600
00:34:19,780 --> 00:34:21,490
In 1921,
601
00:34:21,490 --> 00:34:23,540
Mount Wilson Observatory astronomers
602
00:34:23,540 --> 00:34:25,860
measured surface temperatures on Mars,
603
00:34:25,860 --> 00:34:28,260
finding them to swing wildly
604
00:34:28,260 --> 00:34:30,830
from 15 Celsius at midday
605
00:34:30,830 --> 00:34:35,517
to a lethal minus 85
Celsius just before sunrise.
606
00:34:35,517 --> 00:34:37,330
(ambient music)
607
00:34:37,330 --> 00:34:39,460
Astronomer Walter Sydney Adams
608
00:34:39,460 --> 00:34:43,630
found only vanishingly tiny
quantities of oxygen and water.
609
00:34:43,630 --> 00:34:45,700
(ambient music)
610
00:34:45,700 --> 00:34:47,410
At the Yerkes Observatory,
611
00:34:47,410 --> 00:34:49,680
Girard Kuiper showed the Martian air
612
00:34:49,680 --> 00:34:53,083
to be nearly all
unbreathable carbon dioxide,
613
00:34:54,030 --> 00:34:57,600
yet Mars continued to entice explorers.
614
00:34:57,600 --> 00:34:58,940
In 1949,
615
00:34:58,940 --> 00:35:03,670
rocket pioneer Wernher von
Braun wrote "Project Mars".
616
00:35:03,670 --> 00:35:05,310
It was a sci-fi novel,
617
00:35:05,310 --> 00:35:07,770
but full of factual engineering
618
00:35:07,770 --> 00:35:09,910
and a familiar plot,
619
00:35:09,910 --> 00:35:11,860
a multinational crew from Earth
620
00:35:11,860 --> 00:35:14,130
visits intelligent humanoid Martians
621
00:35:14,130 --> 00:35:18,283
as they desperately try to
save their world a year.
622
00:35:18,283 --> 00:35:19,570
A year later,
623
00:35:19,570 --> 00:35:21,950
Ray Bradbury's "Martian Chronicles"
624
00:35:21,950 --> 00:35:24,170
placed a human colony on Mars
625
00:35:24,170 --> 00:35:27,063
to escape a nuclear war devastated Earth.
626
00:35:29,398 --> 00:35:32,148
(bomb exploding)
627
00:35:33,950 --> 00:35:38,458
The first thermonuclear
bomb was tested in 1952.
628
00:35:38,458 --> 00:35:41,510
(suspenseful music)
629
00:35:41,510 --> 00:35:42,950
In the same year,
630
00:35:42,950 --> 00:35:46,810
Von Braun published an
enhanced "Das Marsprojekt,"
631
00:35:46,810 --> 00:35:48,650
adding a broad technical workup
632
00:35:48,650 --> 00:35:51,411
for a large scale space program.
633
00:35:51,411 --> 00:35:54,160
(energetic music)
634
00:35:54,160 --> 00:35:56,440
After nearly a thousand
launches of people,
635
00:35:56,440 --> 00:35:58,420
propellant and parts,
636
00:35:58,420 --> 00:36:02,140
a flotilla of 10 spaceships
and 70 crew members
637
00:36:02,140 --> 00:36:05,590
would journey across the
gulf between planets to spend
638
00:36:05,590 --> 00:36:08,229
444 days on Mars.
639
00:36:08,229 --> 00:36:11,062
(energetic music)
640
00:36:14,337 --> 00:36:16,860
"Das Marsprojekt" was a rough draft
641
00:36:16,860 --> 00:36:19,320
for what would become NASA's Mercury,
642
00:36:19,320 --> 00:36:22,076
Gemini and Apollo projects.
643
00:36:22,076 --> 00:36:24,743
(ambient music)
644
00:36:27,210 --> 00:36:28,840
In 1955,
645
00:36:28,840 --> 00:36:32,250
Paramount Pictures released
"Conquest of Space,"
646
00:36:32,250 --> 00:36:35,550
modeled on Von Braun's adventurous plans.
647
00:36:35,550 --> 00:36:37,057
- I can give you confounded little reason
648
00:36:37,057 --> 00:36:38,557
for this attempt to reach Mars
649
00:36:39,721 --> 00:36:42,057
and no assurance at all that
it will even be successful.
650
00:36:42,057 --> 00:36:45,400
(suspenseful music)
651
00:36:45,400 --> 00:36:47,560
- [Narrator] To successfully
reach the Red Planet quickly,
652
00:36:47,560 --> 00:36:49,840
engineers realized, might take more power
653
00:36:49,840 --> 00:36:51,663
than chemical rockets can produce.
654
00:36:53,090 --> 00:36:55,280
At the U.S. Los Alamos National Lab,
655
00:36:55,280 --> 00:36:57,360
Project Rover began an effort
656
00:36:57,360 --> 00:37:00,434
to harness atomic fission
to drive spaceships.
657
00:37:00,434 --> 00:37:02,270
(ambient music)
658
00:37:02,270 --> 00:37:03,960
The astronauts' crew capsule
659
00:37:03,960 --> 00:37:07,123
will be placed many meters
from the radioactive engines.
660
00:37:08,340 --> 00:37:11,300
Getting to Mars faster
would cut astronauts dose
661
00:37:11,300 --> 00:37:13,213
of solar and cosmic radiation.
662
00:37:16,640 --> 00:37:17,960
Project Orion,
(loud pulsing)
663
00:37:17,960 --> 00:37:21,853
a different approach to nuclear
rockets started, in 1958.
664
00:37:23,510 --> 00:37:27,270
The idea: detonate nuclear
bombs behind a ship
665
00:37:27,270 --> 00:37:28,403
to push it along.
666
00:37:29,401 --> 00:37:31,960
(loud pulsing)
667
00:37:31,960 --> 00:37:35,179
It's called pulsed plasma wave propulsion.
668
00:37:35,179 --> 00:37:38,050
(loud pulsing)
669
00:37:38,050 --> 00:37:39,710
Outrageous as it seems,
670
00:37:39,710 --> 00:37:42,040
this method could offer rapid transport
671
00:37:42,040 --> 00:37:44,509
to Mars and the rest of the solar system.
672
00:37:44,509 --> 00:37:47,092
(loud pulsing)
673
00:37:49,700 --> 00:37:51,040
By 1961,
674
00:37:51,040 --> 00:37:54,200
the U.S. Nuclear Rocket
Engine NERVA program
675
00:37:54,200 --> 00:37:57,053
had accumulated 17
hours of engine testing.
676
00:37:58,119 --> 00:38:00,410
(inspiring music)
677
00:38:00,410 --> 00:38:02,960
In the Soviet Union,
engineers were working
678
00:38:02,960 --> 00:38:05,469
on nuclear thermal rockets of their own.
679
00:38:05,469 --> 00:38:08,302
(inspiring music)
680
00:38:14,228 --> 00:38:15,810
(ambient music)
681
00:38:15,810 --> 00:38:16,643
As late
682
00:38:16,643 --> 00:38:18,150
as 1962,
683
00:38:18,150 --> 00:38:21,030
the U.S. Air Force was
still making Mars maps
684
00:38:21,030 --> 00:38:23,190
with straight canal lines.
685
00:38:23,190 --> 00:38:25,857
(ambient music)
686
00:38:28,520 --> 00:38:31,350
- [Man] Someday, a manned
trip to Mars and return
687
00:38:31,350 --> 00:38:33,050
may become the mission assignment.
688
00:38:34,340 --> 00:38:36,450
- [Narrator] To accomplish
that assignment,
689
00:38:36,450 --> 00:38:40,350
Krafft Ehricke, a visionary
German American engineer,
690
00:38:40,350 --> 00:38:42,920
introduced the idea of ganging together
691
00:38:42,920 --> 00:38:45,063
clusters of nuclear rockets.
692
00:38:46,730 --> 00:38:48,600
He thought his modular approach
693
00:38:48,600 --> 00:38:51,090
could bring Mars and Venus within reach
694
00:38:51,090 --> 00:38:52,903
as early as the 1970s.
695
00:38:55,260 --> 00:38:58,200
And he identified the most
efficient launch windows
696
00:38:58,200 --> 00:38:59,603
to reach these planets.
697
00:39:01,270 --> 00:39:04,190
Ehricke passionately
believed that human expansion
698
00:39:04,190 --> 00:39:07,345
throughout the solar system
is a fundamental right,
699
00:39:07,345 --> 00:39:09,510
(tranquil music)
700
00:39:09,510 --> 00:39:11,770
and that we are at our most dignified
701
00:39:11,770 --> 00:39:13,710
when we apply the laws of physics
702
00:39:13,710 --> 00:39:17,193
to elevate and protect
our individual freedoms.
703
00:39:20,367 --> 00:39:22,590
Ehricke's and Von Braun's visions
704
00:39:22,590 --> 00:39:24,100
would drive the Boeing Company
705
00:39:24,100 --> 00:39:25,940
to propose the integrated manned
706
00:39:25,940 --> 00:39:29,769
interplanetary spacecraft concept in 1968.
707
00:39:29,769 --> 00:39:33,110
(ambient music)
708
00:39:33,110 --> 00:39:36,740
It bundled up to five
nuclear thermal stages
709
00:39:36,740 --> 00:39:39,923
to propel astronauts and
probes to the nearest planets.
710
00:39:41,810 --> 00:39:43,640
It would have caused half, again,
711
00:39:43,640 --> 00:39:46,380
as much as the Apollo Moon Program,
712
00:39:46,380 --> 00:39:49,870
but it might have delivered
the first crew to Mars by 1986.
713
00:39:53,705 --> 00:39:55,970
(suspenseful music)
714
00:39:55,970 --> 00:39:59,883
The U.S. put boots on
the moon in July, 1969.
715
00:40:01,320 --> 00:40:05,122
Humans had finally touched another world.
716
00:40:05,122 --> 00:40:08,890
(suspenseful music)
717
00:40:08,890 --> 00:40:11,200
With the moon landings fresh in mind,
718
00:40:11,200 --> 00:40:13,160
many people expected the United States
719
00:40:13,160 --> 00:40:15,723
to next target sending astronauts to Mars.
720
00:40:18,232 --> 00:40:20,909
- [Astronaut] Houston,
we've had a problem here.
721
00:40:20,909 --> 00:40:23,059
- [Mission controller]
Say it again please.
722
00:40:24,266 --> 00:40:27,800
- [Astronaut] Houston,
we've had a problem.
723
00:40:27,800 --> 00:40:30,460
(tense music)
724
00:40:30,460 --> 00:40:32,370
- [Narrator] But President Richard Nixon
725
00:40:32,370 --> 00:40:33,990
during the political consequences
726
00:40:33,990 --> 00:40:35,770
of a catastrophic mission failure
727
00:40:36,620 --> 00:40:38,913
would support only a space shuttle.
728
00:40:43,370 --> 00:40:45,310
Though four subsequent U.S. presidents
729
00:40:45,310 --> 00:40:47,683
would ask for various Mars programs,
730
00:40:48,710 --> 00:40:51,450
human space activities
would remain confined
731
00:40:51,450 --> 00:40:52,850
to low Earth orbit
732
00:40:52,850 --> 00:40:54,573
for more than half a century.
733
00:40:58,260 --> 00:40:59,400
By 1990,
734
00:40:59,400 --> 00:41:01,470
some planners realized that cumbersome
735
00:41:01,470 --> 00:41:04,623
bring-everything-with-you space
programs were not workable.
736
00:41:06,030 --> 00:41:08,570
(energetic music)
737
00:41:08,570 --> 00:41:09,820
To remedy this,
738
00:41:09,820 --> 00:41:12,730
engineers Robert Zubrin and David A. Baker
739
00:41:12,730 --> 00:41:15,950
proposed the Mars Direct concept.
740
00:41:15,950 --> 00:41:17,760
It's motto: travel light
741
00:41:19,550 --> 00:41:20,803
and live off the land.
742
00:41:21,972 --> 00:41:24,140
(energetic music)
743
00:41:24,140 --> 00:41:27,490
By making rocket fuel
from the planet itself,
744
00:41:27,490 --> 00:41:30,686
explorers could ensure
themselves a ride home.
745
00:41:30,686 --> 00:41:33,550
(loud rumbling)
746
00:41:33,550 --> 00:41:35,040
By 1993,
747
00:41:35,040 --> 00:41:37,120
key ideas from Mars Direct
748
00:41:37,120 --> 00:41:38,690
had found their way into NASA's
749
00:41:38,690 --> 00:41:40,513
Mars Design Reference Mission,
750
00:41:42,060 --> 00:41:46,000
but consistent congressional
support for humans to Mars
751
00:41:46,000 --> 00:41:47,483
never materialized.
752
00:41:52,210 --> 00:41:53,310
In recent years,
753
00:41:53,310 --> 00:41:56,460
giant aerospace companies
and small private startups
754
00:41:56,460 --> 00:41:58,930
have all adopted bits of Mars Direct.
755
00:41:58,930 --> 00:42:01,597
(ambient music)
756
00:42:02,580 --> 00:42:04,760
Boeing's affordable Mars mission
757
00:42:04,760 --> 00:42:07,080
would send a solar electric sailing ship
758
00:42:07,080 --> 00:42:09,069
to reconnoiter from low orbit.
759
00:42:09,069 --> 00:42:11,736
(ambient music)
760
00:42:12,990 --> 00:42:14,198
Astronauts would descend
761
00:42:14,198 --> 00:42:15,300
(forceful air blowing)
762
00:42:15,300 --> 00:42:17,523
protected by an inflated arrow shell,
763
00:42:19,650 --> 00:42:21,570
touching down like the Apollo missions
764
00:42:22,630 --> 00:42:25,423
to find a previously
landed habitat waiting.
765
00:42:30,783 --> 00:42:33,260
(forceful air blowing)
766
00:42:33,260 --> 00:42:36,510
They'd returned to orbit like
last century's moonwalkers
767
00:42:36,510 --> 00:42:37,853
for the long trip home.
768
00:42:41,880 --> 00:42:43,150
In contrast,
769
00:42:43,150 --> 00:42:46,877
Lockheed-Martin proposes
a Mars-orbiting base camp.
770
00:42:46,877 --> 00:42:49,850
(ambient music)
771
00:42:49,850 --> 00:42:53,159
It's conservatively built by
stacking pairs of modules,
772
00:42:53,159 --> 00:42:56,230
(ambient music)
773
00:42:56,230 --> 00:42:57,203
two tank farms,
774
00:42:58,800 --> 00:42:59,803
two habitats,
775
00:43:02,080 --> 00:43:03,773
two rocket propulsion units,
776
00:43:04,840 --> 00:43:07,628
redundancy for safety far from Earth.
777
00:43:07,628 --> 00:43:10,295
(ambient music)
778
00:43:12,780 --> 00:43:14,950
Astronauts make sorties to the surface
779
00:43:14,950 --> 00:43:16,547
with a single stage lander,
780
00:43:16,547 --> 00:43:19,797
(forceful air blowing)
781
00:43:21,620 --> 00:43:23,790
but this surface-to-orbit shuttle craft
782
00:43:23,790 --> 00:43:26,989
doesn't depend on fuel made on Mars.
783
00:43:26,989 --> 00:43:29,656
(ambient music)
784
00:43:32,280 --> 00:43:35,143
Younger, more aggressive
companies are thinking bigger.
785
00:43:37,160 --> 00:43:39,760
Elon Musk's Space Exploration Company
786
00:43:39,760 --> 00:43:40,900
is developing
787
00:43:40,900 --> 00:43:41,793
Starship.
788
00:43:42,871 --> 00:43:45,538
(loud rumbling)
789
00:43:48,560 --> 00:43:51,070
It's designed to
transport massive payloads
790
00:43:51,070 --> 00:43:52,750
and many people across Earth
791
00:43:55,020 --> 00:43:55,903
and to orbit,
792
00:43:57,710 --> 00:43:59,010
and eventually,
793
00:43:59,010 --> 00:44:01,210
bring millions of tons of material
794
00:44:01,210 --> 00:44:04,453
to the surfaces of planets,
moons, and asteroids.
795
00:44:06,690 --> 00:44:09,160
Like Von Braun and Ehricke before him,
796
00:44:09,160 --> 00:44:11,870
Musk is focused on solving transportation
797
00:44:11,870 --> 00:44:13,203
around the solar system.
798
00:44:15,669 --> 00:44:18,360
SpaceX's eventual goal:
(forceful air blowing)
799
00:44:18,360 --> 00:44:20,120
make Earth life multiplanetary
800
00:44:22,170 --> 00:44:24,340
by building civilization
801
00:44:24,340 --> 00:44:25,173
on Mars.
802
00:44:26,383 --> 00:44:29,050
(ambient music)
803
00:44:31,680 --> 00:44:34,290
In friendly competition with SpaceX,
804
00:44:34,290 --> 00:44:35,430
Blue Origin,
805
00:44:35,430 --> 00:44:38,030
led by Amazon founder Jeff Bezos,
806
00:44:38,030 --> 00:44:41,603
is quietly developing
large boosters of its own.
807
00:44:42,970 --> 00:44:44,210
Blue Origin's vision
808
00:44:44,210 --> 00:44:47,660
is also to extend civilization into space
809
00:44:47,660 --> 00:44:49,760
to preserve Earth's climate
810
00:44:49,760 --> 00:44:52,440
and maintain it as a flourishing biosphere
811
00:44:52,440 --> 00:44:55,400
by moving heavy industry
and power generation
812
00:44:55,400 --> 00:44:56,433
off the planet.
813
00:44:58,290 --> 00:44:59,750
And eventually,
814
00:44:59,750 --> 00:45:03,100
constructing city-sized
free-flying habitats
815
00:45:03,100 --> 00:45:05,890
from materials already in space
816
00:45:05,890 --> 00:45:07,170
on the moon,
817
00:45:07,170 --> 00:45:08,430
asteroids,
818
00:45:08,430 --> 00:45:09,913
and comets.
819
00:45:09,913 --> 00:45:12,677
(tranquil music)
820
00:45:12,677 --> 00:45:15,344
(air swooshing)
821
00:45:16,722 --> 00:45:19,210
(forceful air blowing)
822
00:45:19,210 --> 00:45:20,840
Video game makers too
823
00:45:20,840 --> 00:45:24,461
began to promote the
adventure of populating Mars
824
00:45:24,461 --> 00:45:27,211
(tranquil music)
825
00:45:33,755 --> 00:45:36,422
and the rest of the solar system
826
00:45:37,401 --> 00:45:40,151
(tranquil music)
827
00:45:42,610 --> 00:45:44,240
and some visionaries foresee
828
00:45:44,240 --> 00:45:46,713
the eventual terraforming of Mars,
829
00:45:48,200 --> 00:45:49,880
warming it up,
830
00:45:49,880 --> 00:45:51,953
making it as Earth-like as possible.
831
00:45:55,630 --> 00:45:56,950
But to do this,
832
00:45:56,950 --> 00:46:00,530
these world builders must
find enough greenhouse gases
833
00:46:00,530 --> 00:46:01,663
to heat the planet,
834
00:46:03,430 --> 00:46:07,830
then continuously replenish
its thick atmosphere
835
00:46:07,830 --> 00:46:09,970
and constantly restore its water
836
00:46:11,000 --> 00:46:13,763
as the vapor escapes to space.
837
00:46:18,955 --> 00:46:22,150
(tranquil music)
838
00:46:22,150 --> 00:46:25,203
Still more challenges lurk
on the trickster planet.
839
00:46:26,770 --> 00:46:28,850
Mars surface is everywhere loaded
840
00:46:28,850 --> 00:46:31,580
with toxic caustic perchlorates,
841
00:46:31,580 --> 00:46:33,393
up to 1% of the sands,
842
00:46:34,500 --> 00:46:36,290
putting astronauts at high risk
843
00:46:36,290 --> 00:46:38,273
for thyroid problems and cancer.
844
00:46:39,570 --> 00:46:42,550
Other invisible dangerous
cascade from the sky
845
00:46:42,550 --> 00:46:44,663
unhindered by the thin atmosphere,
846
00:46:48,150 --> 00:46:51,730
the constant rain of cosmic
rays from interstellar space
847
00:46:53,350 --> 00:46:56,240
and highly energetic
particles from solar flares
848
00:46:56,240 --> 00:46:58,136
pelting the planet.
849
00:46:58,136 --> 00:47:00,886
(tranquil music)
850
00:47:01,730 --> 00:47:03,810
Despite the many intriguing renderings
851
00:47:03,810 --> 00:47:06,430
of domed cities on Mars,
852
00:47:06,430 --> 00:47:09,040
settlers for many generations to come
853
00:47:09,040 --> 00:47:11,150
will have to spend most of their time
854
00:47:11,150 --> 00:47:12,770
in thickly roofed shelters
855
00:47:14,060 --> 00:47:15,683
or underground.
856
00:47:20,230 --> 00:47:22,343
Yet there may be hope.
857
00:47:23,380 --> 00:47:25,423
The rise of autonomous machines,
858
00:47:26,650 --> 00:47:27,973
advanced robotics,
859
00:47:29,360 --> 00:47:31,040
artificial intelligence,
860
00:47:31,040 --> 00:47:32,740
and augmented reality
861
00:47:32,740 --> 00:47:35,863
can extend human senses to
the surface of the Red Planet.
862
00:47:40,500 --> 00:47:42,730
And someday we may send devices
863
00:47:42,730 --> 00:47:45,163
to terraform Mars on their own.
864
00:47:46,460 --> 00:47:48,610
Human emigres from Earth
865
00:47:48,610 --> 00:47:51,290
could eventually build communities
866
00:47:51,290 --> 00:47:53,380
on a ready-made planet.
867
00:47:53,380 --> 00:47:56,130
(tranquil music)
868
00:47:57,926 --> 00:47:59,640
(energetic music)
869
00:47:59,640 --> 00:48:01,430
In 2033,
870
00:48:01,430 --> 00:48:04,450
Mars will come into a
particularly favorable position
871
00:48:04,450 --> 00:48:06,163
for launching human cruise,
872
00:48:08,330 --> 00:48:09,163
but who will go
873
00:48:10,280 --> 00:48:11,113
and why?
874
00:48:14,340 --> 00:48:17,780
Mars has seduced so
many seeking notoriety,
875
00:48:17,780 --> 00:48:20,660
promising an entire new world to explore
876
00:48:21,670 --> 00:48:22,713
or exploit.
877
00:48:25,020 --> 00:48:28,480
Ingenious engineering may
find elegant solutions
878
00:48:28,480 --> 00:48:30,113
for how to get us to Mars,
879
00:48:32,010 --> 00:48:33,710
but what becomes of us
880
00:48:35,260 --> 00:48:36,583
once we get there?
881
00:48:37,431 --> 00:48:40,098
(pensive music)
64864
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