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00:00You have to get down into this gravity well, which is Jupiter.
00:04It's a hard navigation problem.
00:06And thirdly, most importantly, is Europa exists in a very, very dense, highly deadly radiation environment.
00:13In fact, a human being, or a shielded human being, would die in about ten minutes on the surface of Europa.
00:19So it's a very, very difficult place to go.
00:25We will have Europa in our future, in our children's future.
00:28The idea of exploring Europa is not going to go away.
00:31Our kids are going to be exploring Europa.
00:33And sometime in the future, we are going to be sending a submarine down below the crust of Europa into an alien ocean, searching for life.
00:43And that's a very, very exciting prospect.
00:49The search for life in the universe is not restricted to one icy moon half a billion miles away.
00:58Closer to home, there is a target that has long captured the fancy of Earth-bound dreamers.
01:05Mars, the red planet.
01:10At its nearest orbit, it's only 35 million miles away, the closest planet to Earth in the solar system.
01:17When the weather is clear, it can be seen shining brightly like a star in the night sky.
01:24Nearly 100 years ago, astronomer Percival Lowell built his own observatory so he could dedicate himself to the study of Mars.
01:32Lowell observed a pattern of dark stripes etched into the Martian surface.
01:45He speculated that some willful life species built canals in an attempt to move water around a slowly dying planet.
01:53The idea of a race of Martians captured the imagination of the public.
01:57Well, Percival Lowell had a good imagination.
02:01Astronomer Dr. Adam Bruckner of the University of Washington doubts any form of life intelligent enough to construct canals ever lived on Mars.
02:10Earlier in the 19th century, an Italian discovered what he termed called canali, which really he meant to mean channels.
02:19And somehow that got to be interpreted as canals, and the minute you say canal, you immediately think of an intelligent civilization or life that would have built them.
02:34And somehow with this in their minds, it distorted what they saw when they looked through the telescope.
02:41Nonetheless, we set out to meet our neighbors.
02:58Fueled by the Cold War between the two countries, in the late 1950s, both the United States and the Soviet Union began aggressive space programs.
03:06The Soviet satellite Sputnik kick-started his space race to put the first man into orbit, then to step foot on the moon.
03:12Down two and a half, forward, forward, forward, 30 feet down, two and a half, picking up some dust, down a half, 30 seconds, forward, just, contact light.
03:27I'm going to step off the land now.
03:37That's one small step for man, one giant leap for mankind.
03:50The United States quickly dominated the race.
03:53Leading the U.S. effort was a brilliant rocket scientist named Werner von Braun.
04:00Von Braun got his start designing and building V-2 rockets for Nazi Germany during World War II.
04:06After the war, von Braun went to work for the United States, heading up the creation of the U.S. space program.
04:12Just two weeks after Neil Armstrong walked on the moon, von Braun pitched to NASA a bold plan to reach Mars by spacecraft.
04:32The plan called for a Martian landing by 1982.
04:39But the United States government decided not to pursue the project, grounding von Braun's dream for the moment.
04:50While von Braun was losing in his bid to steer the United States towards Mars, the Soviet Union refocused their efforts onto the Red Planet.
05:06To get to Mars takes approximately six months, depending on the particular time when you go.
05:14Roughly about every 26 months, the Earth and Mars are in the right position to be able to go there, at least with chemical propellants.
05:21It would take anywhere from about six to seven months to get there and approximately the same amount of time to come back.
05:29But you have to stay on Mars about a year and a half for the planets to line up again so you can come back.
05:37The Soviets wanted to know if it was possible to undergo such a rigorous journey.
05:41The Soviets started their human endurance flight tests in 1970 with a flight of Soyuz 9.
05:51Cosmonauts Andriar Nikolayev and Vitaly Sevastyanov stayed in space for a then record 18 days.
05:59But their return to Earth did not go smoothly.
06:11Neither Nikolayev nor Sevastyanov were able to stand on their own two feet.
06:21The zero gravity conditions of space robbed them of essential bone and muscle mass.
06:30Further research showed that after just five days in space at zero gravity, a human will lose nearly 30% of their muscle strength.
06:38When you're in zero gravity, the body all of a sudden doesn't have to fight gravity like we do on Earth.
06:45Even when we're standing or sitting, all our muscles are always working, pushing, pulling, keeping us in balance.
06:52So the body in that sense is always exercising even when we're not doing anything.
06:57So if just two weeks without gravity would incapacitate a cosmonaut,
07:01the Soviets had to grapple with what effect a seven-month flight would have on the body.
07:06Would a cosmonaut even be able to function once reaching Mars?
07:15One of the most significant problems the specialists have to solve
07:20is the provisioning of human health in a safe work environment on Mars
07:24and when returning back to Earth.
07:26A prolonged state of weightlessness should also be taken into account.
07:29The 1986 launch of the Mir space station was the Soviets' major foray into testing the limits of long-term space habitation.
07:47Mir had room for six cosmonauts.
07:52Inside the space station, they worked and lived within the cramped confines of a control room,
07:58several laboratories, one shower, and a space-age dining room.
08:01Cosmonaut Valery Polyakov became the number one guinea pig in a battery of exercises designed to maintain his bone and muscle mass.
08:12Polyakov followed a vigorous two-hour workout regime, utilizing 60 different drills designed to cut down boredom.
08:23In order to receive any benefit from his daily workouts, Polyakov needed to strap himself to the floor to simulate gravity.
08:30My task was to improve this set of exercises during the mission based on my knowledge of the system,
08:43peculiarities of the body's behavior under conditions of weightlessness,
08:47and the condition of the cosmonaut's muscles.
08:56Polyakov set a world record for time spent in space.
08:59438 days, more than enough time to fly to Mars and back.
09:14On his return to Earth, Polyakov walked away from his spacecraft, mostly under his own power.
09:21He did suffer a 15% decline in muscle weight, not enough to hinder his ability to do his job on Mars if he had arrived there.
09:33But while Polyakov's body stood up to the rigors of nearly 15 months on Mir, his mind didn't do so well.
09:43These complications exhibited themselves in petulance and obsessive fear.
09:53I missed my family. I was sad. And that lowered my efficiency.
09:57Two months into the mission, Polyakov's daily medical report started showing signs of mental stress,
10:09deteriorating communication skills and rebelliousness.
10:13It had an effect on the general background of relationships, cruelty, loss of friendliness.
10:18It is an unusual environment for humans as a social creature.
10:32Humans are created for communication, for sharing results of success and failures.
10:36It is a problem if a human only communicates with two or three from the crew, not with big audiences.
10:45Because of that, one could have some psychological problems.
10:48Initially, stress levels dropped as the cosmonauts became adjusted to living aboard Mir.
11:06But two months later, the initial stress indicators returned.
11:11As stress increases, data showed the likelihood of making errors increased as well.
11:16Being cut off from the known world while being surrounded by the enormity of space is not too much fun.
11:32A later isolation test was conducted in a Mars spacecraft simulator.
11:39During psychological stress situations, it is useful to find ways to distract yourself from the problems.
11:44Turns out, gardening in space provides the same benefits as gardening on Earth.
11:52The crew grew young wheat in the Mars simulator for a fresh food source.
11:57Cosmonaut Alexander Iviansky found great comfort when he touched the wheat, especially in high-stress situations.
12:04The scientists made a conclusion that natural elements such as plants could have a special influence on humans.
12:15The cosmonauts began checking on their wheat field up to seven times a day,
12:23spending extra time caring for the wheat and discussing the crop with each other.
12:28It was graphic evidence that people need this contact and like it.
12:37This contact nicely influences their mood and emotional state.
12:41We had grown something with our own hands.
12:43We had something alive in the lifeless metal that surrounded us.
12:46The live plant helps establish ties with Earth, with nature.
12:53I would say that this is the essence with which the human mind is based.
13:05While the Soviet and American space programs were researching the strains a human would undergo traveling to Mars,
13:10other scientists took a more careful look at what a space traveler would find upon arrival on the red planet.
13:22The basic reason why Mars is considered to be the most interesting planet in the solar system other than the Earth
13:29is because it's so similar to the Earth.
13:32University of Washington astrobiologist Dr. David Catling studies the Martian atmosphere and surface for NASA.
13:38It's thought to be the planet which is probably the most habitable in the solar system.
13:44In the 1960s, the sparse details humans knew about Mars came from telescope observations.
13:51There was debate about the meaning of the canal-like markings scored across the planet's surface.
13:58Breaking down the light emanating from Mars revealed the planet's atmosphere is thin and cloudy,
14:03dominated by unbreathable carbon dioxide gas.
14:05Photographs radioed back to Earth from robotic fly-by missions revealed the desolate world.
14:06Photographs radioed back to Earth from robotic fly-by missions revealed the desolate world.
14:07pock-marked by impact craters much like Earth's barren lifeless moon data in the form of Earth's orbit.
14:14Photographs radioed back to Earth from robotic flyby missions
14:30revealed the desolate world,
14:33pockmarked by impact craters much like Earth's barren, lifeless moon.
14:38The landscape is blanketed by a thick, reddish-brown dust.
14:41The dust gives the planet its ruddy hue in the night sky.
14:47And even though the planet's temperature swings from 80 degrees Fahrenheit
14:50to a deep freeze of minus 207 degrees,
14:55hope of finding life still lingered.
14:58An environment which is similar in some ways but very different in others,
15:02and the principal difference is the fact that it's cold and dry compared to the Earth.
15:07Mars is half the size of the Earth and has one-third the gravity.
15:13The planet is tipped over at a 25-degree angle similar to the Earth,
15:18setting up, again like Earth, four different climatic seasons.
15:22And the red planet's day is 24 hours, 37 minutes long.
15:26The planet's surface is also distinguished by geological features similar to Earth.
15:34Near Mars' equatorial region is the Valles Marineris.
15:38This massive canyon would stretch from New York to Los Angeles
15:42and runs 31,000 feet deep at its lowest point,
15:47nearly six times as deep as the Grand Canyon in Arizona.
15:51And breaking through the thin Martian atmosphere is the Olympus Mons,
16:0117 miles high, three times taller than Mount Everest.
16:06Olympus Mons is the tallest volcano in the solar system.
16:10But the question long vexing scientists is whether there is or ever was water on Mars.
16:18And so, too, the question of life on Mars.
16:21There are sort of two camps.
16:23One camp saying that Mars was once warm and wet,
16:26and the other camp saying that Mars has never really been wet.
16:30It's always been dry.
16:31And so, it certainly will make a big difference as to whether life can take root
16:38if Mars was never warm and wet,
16:40and if it was always a dry, kind of a freeze-dried planet the way we see it today.
16:47The Viking missions in 1976 filled in more details.
16:52Two orbiting spacecraft and two Martian landers
16:55beamed more than 55,000 portraits of Mars back to Earth over the next decade.
17:01Of particular interest are these photographs of undulating lines running between craters.
17:09They run together to form one thick line,
17:13much as a tributary system of streams and creeks meet and flow into a river on Earth.
17:18Other photographs revealed evidence of what could be traces of huge floods.
17:24The top of this valley appears to have been formed by a confluence of rushing water,
17:29carving a wide channel extending more than 60 miles across the Martian surface.
17:34When we look at the channels on Mars,
17:37we find that the most striking ones emanate from the canyon region around Valles Marineris.
17:44To create these very wide channels going for thousands of kilometers requires an awful lot of water.
17:50There are analogues on the Earth to these channels.
17:55For example, in eastern Washington state, there's an area called the channeled scab lands.
18:00But that, in fact, is dwarfed by what we see on Mars,
18:05that we would require 10 to 100 times as much water as what was required in eastern Washington
18:10to make these channels on Mars.
18:12In 1997, the Mars Pathfinder touched down on Mars.
18:32Photos from the lander show a landscape littered with rocks and boulders.
18:36There appeared to be pebbles and cobbles that were somewhat rounded,
18:42and some of the rocks appeared to be perched as if they'd been deposited in a big flood.
18:47And so these indications were taken to suggest that this was, in fact,
18:53verification of a large flood channel.
18:56You can also look at some of these rocks and their lower surfaces as covered in dust,
19:01and that suggests that perhaps they would have been exhumed by the wind.
19:05So we also see signs that the wind has had a large effect in this region as well.
19:10So we have to try and disentangle what's been caused by the wind
19:14and what may have been caused by water.
19:23Further evidence comes from a valley at the base of the Hadriaca-Patero volcano.
19:31Called the Tao Vallis, photographs show clear signs of water courses
19:40in the sides of the cliffs, where there is little sign of wind erosion.
19:45Researchers believe only water could have gouged the cliff faces in this manner.
19:51More than 100 rock formations like this have been found scattered across the Martian landscape.
19:56What is not known is, if there was water, where did it come from, and where did it go?
20:04Now the Mars surface is desert, cold, dry, dusty, seemingly lifeless.
20:12But appearances could be deceiving.
20:13While vast oceans of water may be the most promising incubators for life,
20:26minute amounts of water are enough for tenacious life forms to take hold.
20:30Dr. Emre Freedman has found living organisms in some of Earth's most inhospitable places.
20:43Here in Death Valley, California, Freedman finds primitive forms of life where water is extremely scarce.
20:50What I found out is, nearly everywhere on Earth, there is life.
20:59And you have to look for it only carefully.
21:02And there is, of course, something which is limiting life, and this is water.
21:06Without liquid water on Earth, there is no life.
21:10And if there are even traces of liquid water, probably life finds a way to establish itself.
21:16Life forms that survive and create a niche for themselves in incredibly harsh environments are called extremophiles.
21:26These are species that find a home in surprising places like barren deserts, boiling hot springs, and frozen wastelands.
21:34One could say that life is incredibly inventive to find ways to live in very harsh places.
21:42And also, it is very tough.
21:46So you do not see, you do not need much water.
21:49And even traces of water are enough for some organisms to establish themselves.
21:58Freedman credits his initial discovery to pure chance.
22:02He initially looked for tenacious life forms in soil.
22:06But a friend suggested that maybe the world's most extreme life forms lived in rocks.
22:10So here are, these are green organisms, which are photosynthetic, under the stones.
22:19The inside of rocks is an important microbial habitat.
22:24And that is a shelter, that is a niche, where microorganisms can survive in otherwise extreme and deadly hostile environments,
22:31like in hot deserts or in Antarctica.
22:33The other one is, for instance, that soil is not the best habitat for microorganisms in very extreme environments.
22:45And maybe, also most important, that there are still undiscovered niches, undiscovered possibilities.
22:53We have to look very, very carefully, you know,
22:55and look where you would not expect to find something, because life may be there.
23:01Freedman has collected and catalogued microbial life subsisting in some of the harshest of Earth's environments,
23:17places that would rival the extreme cold of Mars.
23:20He keeps his Antarctic rock samples preserved in this massive freezer at Florida State University.
23:29It took me some time to realize that life is present in very unlikely places.
23:38You know, it took me a long time, many years, to realize this.
23:44And I became, with this time, sort of bolder and more daring to look at unlikely places.
23:53I didn't find everywhere.
24:04Extremophiles have been found in such unlikely places as this Swedish nuclear waste storage facility,
24:101,500 feet underground.
24:14At this tremendous depth, and with no available sunlight, microbial colonies flourish.
24:34It's not an issue of the sun, but an issue of what is found here, inside the depths of the Earth.
24:40Dr. Karsten Petersen of Sweden's Gutberg University may have unlocked the secret of their survival.
24:53At first, I was shocked, but I did believe that microorganisms were living under Earth's surface,
24:59and I knew that these microorganisms could survive well in even the most severe of environments.
25:04After my initial excitement subsided, I became very happy with the thought that organisms can live in this environment.
25:14Peterson then had to figure out just how these extremophiles were able to thrive here.
25:19Energy is absolutely necessary for living things, and in order for living things to form, oxygen and other materials are required as well.
25:34If you are a plant, you get your energy from the sun, but I think the microorganisms under the Earth are getting their energy from the gas in the groundwater.
25:42Peterson is still puzzled by where this essential gas comes from, and how it helps these cellar-dwellers thrive.
25:54This is a very difficult question.
25:58I think this comes from very deep under the Earth's surface, from the Earth's mantle, 50 to 100 kilometers under the Earth, even deeper than that.
26:06We know that gases like hydrogen and methane are being formed.
26:11This type of gas is very slow-moving, but I think it does make its way to the microorganism level, and the microorganisms eat the gas.
26:22In theory, there is enough internal energy rising up from the Earth's core to support an enormous population of microscopic life.
26:30It is thought that these underground extremophiles have a combined weight rivaling the weight of all the species living on the surface of the Earth.
26:41The fact that the numbers are nearly the same means that there are quite a lot of living organisms under the surface as there is above the surface.
26:49These microorganisms have been around much longer than the rest of us.
26:57So what I am essentially saying is life can exist in far more places than we have all imagined at this point.
27:04If there is a possibility of life living under the surface of the planet as there is on Earth, and if this life lives by getting its energy from the planet itself instead of the Sun,
27:19the existence of life or the possibility of existence of life on other planets becomes quite probable.
27:26It is Joel Hagen's job to dream up what those life forms might look like.
27:40I have always been fascinated with what else was going on in the solar system and what else was going on in the universe besides all of the amazing things on Earth.
27:57While these creatures are figments of Hagen's imagination, he approaches his creations like a scientist, evaluating reams of astronomical data and piles of planetary photos.
28:08For me, thinking about creating other life forms in the solar system was an outgrowth of astronomical painting of the geology and landscapes of other planets.
28:19Each of Hagen's creature creations is based upon the planetary conditions where it might be found.
28:25The fun in creating these things is not in being just fanciful and totally imaginary about it, but in following as much as possible a foundation of scientific principles and following the principles of science to grow a life form rather than just pull it out of thin air.
28:45Hagen imagines that on a gaseous planet with no visible continents or habitable ocean, life may take on the form of jellyfish-like inhabitants.
29:03They float through the atmosphere and survive by converting temperature differences and chemicals of the gas into useful energy.
29:11A world with an extreme amount of gravity would require organisms with hardy skeletons and a very slow gait.
29:23On this imaginary planet where there is no carbon, silica-based life forms would have crystalline bodies.
29:45One of the things that I've always been a little annoyed with in science fiction movies is that somebody will land on another planet and there's one creature living there or one culture dominating this planet.
30:00And I think that the real fascination in understanding life on our planet and then imagining what life might be like on another planet is realizing that these are biomes, these are ecosystems, whole ecologies where life forms interact with each other.
30:16I see a community and then I begin focusing on what the individuals might be like.
30:22The one type of creature you won't find in Dr. Hagen's portfolio is a human-like being.
30:30One of the ways that I sometimes try to imagine a completely different animal is to try to imagine that it has a totally different foundation of metabolism, of biochemistry.
30:49And these are pretty radical things to play with. These are very imaginary.
30:52But it's interesting to think about how far does it go?
30:56Does it actually acquire intelligence? Is intelligence some inevitable quality that emerges?
31:03Is it an accident? Is it just another adaptation?
31:06Almost like becoming faster or stronger or developing bigger teeth to capitalize on other life forms around you?
31:13Is intelligence just simply another way to catch food and reproduce?
31:18I think that the question of whether there is intelligent life,
31:43I think that the question of whether there is intelligent life beyond Earth is essentially
31:50the same question as whether there is life beyond Earth.
31:55At Emory University in Atlanta, intelligence expert Dr. Lori Marino focuses her research
32:01on the elevated brain power of marine mammals such as dolphins.
32:07For Dr. Marino, nature, life and intelligence evolve hand in hand.
32:13If you have mobile life on a planet, particularly multicellular life, then that life is going
32:20to need a nervous system to sense the environment.
32:23Once you have a nervous system, you have the makings of intelligence.
32:35The large, pale brain on the left is from a dolphin.
32:38The smaller brain on the right, a human.
32:41The similarities reflect a connection between mammal and man, but to be intelligent does
32:47not mean possessing mental abilities similar or equal to human beings.
32:52Dolphins are often described as intelligent because they can do human-like things.
32:58Communication is a sign of intelligence, but all organisms communicate to a greater or lesser
33:04degree.
33:05And what we are looking for when we look for complex communication is something like human
33:11language.
33:12Yet dolphins have a sophisticated language humans have yet to crack.
33:20That inability to decipher dolphin communication leads Marino to believe if intelligent life exists
33:27outside of Earth, it will have evolved skills humans may not even recognize.
33:32So, do you think it's possible that there's an intelligence but we'll never know about it
33:38because it's so different from ours, we'll never be able to connect with it on any level at all?
33:42Yeah, that's something that, you know, a lot of people think about.
33:46Maybe something on another planet might have a brain but very differently organized according
33:52to different principles and have the equivalent of a neuron, but it won't, it may not look anything
33:58like our neurons or our brain.
34:09So far we can only say that, well, we're looking.
34:11We haven't found the aliens yet.
34:15Seth Shostak is chief astronomer for the SETI Institute in California.
34:21The idea that we should be alone in a cosmos which is enormously vast and implacably hostile.
34:35The universe is cold, it's dark, it's violent, the universe is very hostile.
34:39And the thought that in this incredible enormity that we are the only creatures able to look
34:46at it and understand something and talk about it, that would be a very discouraging thought.
34:51That would be a depressing thought.
34:52Our search involves, in fact, trying to eavesdrop on signals that might be coming from other
34:57societies.
34:58Now, how do you do that?
34:59Well, we principally look for radio signals.
35:02We're using the world's biggest antennas, the one down in Puerto Rico, it's a thousand
35:06feet across, you've seen it in the movie Contact.
35:09We use a big antenna because the bigger the antenna, the more of this cosmic static you pick up.
35:18Space produces a lot of natural radio static.
35:20The stars don't make too much radio noise, but the gas between the stars does.
35:24Makes a lot of radio static and it just sounds like turning on your bathroom faucet and leaving
35:28it running.
35:29Pshhh.
35:30Not terribly interesting to listen to, but it's there.
35:32But we're looking for something that's different.
35:34We're looking for the kind of radio noise produced by transmitters.
35:37The thing that's different about a transmitter is that it produces the radio noise at one
35:41spot on the dial.
35:43The trick is finding that one channel among billions of channels.
36:01The limiting factor is the signal itself.
36:05As it travels great distances through space, it becomes weaker.
36:10This means the signal must be on for a very long time in order for SETI to capture it back
36:14on Earth.
36:16Success means, of course, that we have picked up a signal that is indisputably coming from
36:22some other society, something with intelligence.
36:25I'll go out on a limb and say that we're going to succeed not a hundred years from now, not
36:30a thousand years from now, we're not talking about that, but in the next two to three decades.
36:33I think this is something that's within our lifetime.
36:38Historically, landing experimental probes on Mars has been fraught with failure.
36:44At the beginning of 2004, just two weeks after a British Mars rover disappeared while attempting
36:50to land, the United States rover Spirit made its own attempt.
36:55We've just passed one minute atmospheric entry, current altitude 121 miles, current velocity
37:0112,084 miles per hour.
37:03The variant of the Mars atmosphere is when the first danger appears.
37:08Too shallow of an approach, the rover skips off into outer space.
37:13Too steep of an entry, the spacecraft can burn up.
37:20Landing is the next critical moment.
37:23The rover does not maneuver into a landing position, using onboard rockets to slow its descent
37:28for a gentle landing.
37:29Instead, the rover is encased in a large balloon-like enclosure that absorbs the impact as the rover
37:37literally is dropped onto the Martian surface.
37:40The balloon is designed to cushion the highly sensitive technology packed into the rover structure.
37:47But a crash landing is always a distinct possibility.
37:53The best way to know what's happened 35 million miles away is if the rover fires up its computer
37:59and begins sending radio and video signals back to Earth.
38:06It was very important for NASA to have these rovers be a success because NASA has had some recent failures
38:13in the Mars program.
38:14The Mars program.
38:15The Mars program.
38:20The Mars program.
38:24You can use high rate students who are surely athletic testing.
38:26It will also be projected from the Apollos.
38:28You know that June 1, please have spun down on me now.
38:36You can only live upon próxima rotation afterlie at the moment.
38:40That happens ahead of time to a cliffler.
38:44Do you see it?
38:59What do we see?
39:14NASA landed two rovers successfully in January 2004, four weeks apart.
39:22That's looking down on our vehicle.
39:23The close-up images their cameras began beaming back to Earth of the Martian surface has changed
39:29the scientific landscape.
39:32Oh my God.
39:36They've been a stunning success.
39:37They've gone essentially according to plan.
39:39There's been some hiccups on the surface.
39:42And they're both roving around and they're both discovering new things every day.
39:46The rovers landed on two opposite sides of the planet, giving a widely varied perspective
39:52of the geology on Mars.
39:54The second rover, Opportunity, found itself inside a small crater, giving scientists the
40:00first ever look at what lies just beneath the Martian surface.
40:05Near the rim of this crater, there are all these rocks, these light-toned rocks that basically
40:12stood out.