New discoveries of alien earths reveal vital clues in finding extraterrestrial life. Using the latest science and technology, experts reveal the strange landscapes and oceans of these distant worlds.
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LearningTranscript
00:02500 light years away, a twin earth orbits a star much like our sun.
00:10Could this distant world also have life on its surface?
00:14One of the greatest questions that humans have asked is, are we alone in the universe?
00:20Closer to home, we've already discovered moons with ice caves and hidden oceans.
00:29What secrets do they hold?
00:32Ideas that were science fiction a year ago are reality now.
00:37To unlock the mysteries of these alien worlds, we will strip them to their cores,
00:48dive into their hidden oceans, and peel open their crusts.
00:57To reveal the secrets of the strangest places in the universe.
01:15Today, across the planet, the search for alien worlds is on.
01:21High-powered telescopes scour the night sky.
01:29Probes scout out exotic moons and planets.
01:34While scientists explore the most extreme environments on Earth.
01:40All of our evolution, we've wanted to know what's over the next hill, what's over the ocean, what's off the
01:46planet.
01:46As scientists discover alien environments in deep space, they also rethink mysteries on our own planet.
01:55And what we see is that every niche on Earth where life can possibly exist, it's there.
02:01Now, question is, is the Earth the only place in the universe where there's life?
02:07The quest for alien worlds takes scientists into the unknown.
02:13They scour the depths of our solar system.
02:18Where frozen moons spew ice into space.
02:27And harbor hidden oceans.
02:33Space probes pierce thick clouds shrouding strange worlds.
02:38To reveal hostile icy landscapes and liquid methane lakes.
02:48Astronomers search for Earth-like planets deep in the Milky Way.
02:55And listen for messages from alien civilizations echoing through the cosmos.
03:02The galaxy is huge.
03:04It just crushes our ability to grasp scale into dust.
03:09To find an alien world, we don't have to look very far.
03:15There's a promising candidate right in the middle of our own solar system.
03:22A strange icy world lurks in the mists of Saturn's outer rings.
03:29Enceladus, a tiny frozen moon the size of North Dakota.
03:36Its icy surface reflects sunlight like a mirror.
03:42The ice stretches over 60 miles deep.
03:50Down towards the moon's rocky core.
03:57Could life exist in the darkness of this alien world?
04:01Far beyond the reach of the sun?
04:09Scientists explore extreme places on Earth to help solve this mystery.
04:16Enceladus has a perfect parallel.
04:18The Don Edwards Nature Refuge.
04:21A dried out salt marsh.
04:25The two-inch thick salt crust here completely blocks out the sun, keeping the ground below in eternal darkness.
04:34Most of the other worlds we're interested in in our solar system, it's the subsurface where we're likely to find
04:41any life at all.
04:46NASA scientist Chris McKay hunts for life that lives in the dark.
04:52Methanogens, tiny microbes that thrive underground.
04:57They were among the first life forms to appear on Earth over three and a half billion years ago.
05:04Perfect examples of how life adapts and evolves.
05:09On Earth, anywhere where we find methanogens, I'm interested.
05:14They don't like oxygen.
05:15They eat hydrogen.
05:17They don't have any use of sunlight at all.
05:19They live in the deep subsurface.
05:22They are my favorite candidates for micro-astronauts on another world.
05:30Chris searches for samples of methanogens under the salt crust.
05:37The salt is providing a protection and also a barrier.
05:42Here in the top is just the salt, the white layer.
05:46Then the green layer.
05:47These are organisms that use sunlight, photosynthetic.
05:50Then the pinkish layer.
05:51These are organisms that really like salt.
05:55Then below them is the black stuff.
05:58In there are methane-producing organisms.
06:03Methanogens swarm through this black mud.
06:06One million of them fit on a pinhead.
06:09This will be a little tiny model for a huge world, Enceladus.
06:13And by understanding this in detail, we'll develop insights that we can then generalize with.
06:20As scientists examine Enceladus more closely, this alien world becomes even stranger.
06:27With a surface temperature of 330 degrees below zero.
06:32All water here should be frozen solid.
06:35But the tiger stripes on the south pole open a portal to an amazing water world.
06:47These gigantic cracks in the icy surface lead to a huge salt water ocean hidden underground.
06:56Loaded with hydrogen, it is perfect methanogen food.
07:01They could thrive in this briny liquid.
07:04As Enceladus orbits Saturn, the planet's massive gravity stretches the icy canyons apart.
07:12The ocean water escapes.
07:16Shooting out of the tiger stripes in huge icy plumes.
07:23In March 2012, scientists piloted the Cassini satellite through the plumes of Enceladus.
07:32The satellite's instruments detected traces of simple carbon-based molecules that are the building blocks of life.
07:42Chris McKay is now planning a mission to bring a sample of the plume back to Earth.
07:48He hopes it will be full of methanogens.
07:51I think the most exciting thing about Enceladus is there's material coming out right into space.
07:57We don't have to drill.
07:58We don't have to dig.
07:59We don't have to search.
08:00We just fly right through and grab it up and bring it back home.
08:05It's wonderful.
08:06It's like there's a big sign.
08:07Free samples.
08:08Take one.
08:13These icy eruptions send debris from this alien world into orbit around its parent planet, Saturn.
08:23The water spraying out of the tiger stripes freezes instantly.
08:30And shoots hundreds of miles into the sky over Enceladus.
08:36Some of the ice particles escape the moon's low gravity and drift away to form the icy outer ring of
08:43Saturn.
08:46If there's life on Enceladus, could it escape?
08:49And from Saturn, spread through the galaxy?
08:56As scientists look ever deeper into space, the possibilities for new worlds keep growing.
09:02As we look out at the universe, we recognize that it's the same laws of physics.
09:07It's the same chemistry.
09:09And it's the same composition of stuff everywhere.
09:12That chances are, life is everywhere throughout the universe.
09:17But every alien world we find has new mysteries.
09:23Could an ice cavern hidden inside a moon also be home to a new kind of life?
09:43Across the planet, scientists scan the night sky in search of alien worlds.
09:51They hunt for evidence of a precious liquid that turns barren rocks into thriving ecosystems.
09:59Water.
10:02Life on Earth is very diverse.
10:04Not all life forms require oxygen.
10:06Not all life forms even require sunlight.
10:09It looks like every single organism on the Earth requires liquid water.
10:14Water is everywhere in our outer solar system.
10:18But we mostly find it as ice covering comets and moons.
10:25These frozen landscapes endure perpetual winters.
10:31With temperatures ten times colder than a North Pole winter.
10:37But life may still hide among ice crystals.
10:41Just because a planet is very different from the Earth.
10:44It could be a lot warmer.
10:45It could be a lot colder.
10:46That does not guarantee that there's no life there.
10:49In fact, if you think about our own planet.
10:51Everywhere on the planet, evolution has found some sort of niche for life to exist.
10:56Life on Earth has found a way to fight back against the cold.
11:01In Washington's North Cascade Mountains, snow and ice cover the ground year-round.
11:08This is my backyard.
11:10And what we have here in Washington's North Cascades is a really deep snowpack.
11:16I take Harvey as much as I can.
11:19Harvey loves the snow.
11:23Professor Robin Kotner searches for life that can defy the odds in a frozen world.
11:29Since life on Earth is a product of a couple of billion years of evolution,
11:33it's impossible to know exactly what life in other places in the solar system or beyond would look like.
11:40So all we can do is go to places on Earth where there are similar conditions
11:45and see what life is doing there.
11:49Robin hunts for life that could take hold on the icy moons of our solar system.
11:57Europa is one of 67 moons that orbit Jupiter.
12:04Surface temperatures can drop to 370 degrees below zero.
12:10Rock-hard ice covers the surface.
12:15But strange marks running across the surface betray activity hidden deep below.
12:25Right under the hard outer crust, a layer of softer ice remains in constant flux.
12:35Slushy currents move life-giving minerals around the moon.
12:40They create a fertile environment that life could exploit.
12:48On Mount Baker, Robin locates a type of life that could also exist on Europa.
12:55I see some right around here.
12:57Oh, wow.
12:58Pink snow.
12:59So there's some snow algae living here.
13:02Robin's algae is called Chlamydominus nivalis.
13:05But more commonly, watermelon snow.
13:10Unlike plants that need soil to thrive, the algae can grow on naked crystals of frozen water.
13:18They produce a pink sunscreen that protects them from intense sunlight.
13:24It's a little bit pinker just under the surface here.
13:27Ooh, this is good.
13:29And it's getting pinker as I dig down.
13:31And so the conditions for the algae are even better in the subsurface.
13:36The Mount Baker algae can survive winter temperatures of 14 below zero.
13:43Europa's surface remains 20 times colder year-round.
13:53But two miles below the surface, an icy cavern traps a pocket of water larger than the Great Lakes.
14:02Salt in the water acts like antifreeze.
14:07Twenty miles below the surface, the landscape changes again.
14:14The ice opens out into a hidden ocean.
14:20It holds twice as much water as all of Earth's seas, and is ten times deeper.
14:32What kind of life might exist here?
14:38I'm just sampling here to help us understand why they're happy here,
14:43and then that gives us some range of possibilities that we might search for outside of this planet.
14:50The algae on Mount Baker have adapted to survive in a frozen world.
14:55This group can be found in hot spring environments, in deep hydrothermal vent environments,
15:01in snow environments, in dry Antarctic deserts.
15:04And they're pretty adaptable.
15:07Oh, snow algae. I love you.
15:12Robin's algae are the ultimate survivors on Earth.
15:18Now, scientists have found a new planet where this type of algae could thrive.
15:25A close neighbor to Earth, it's 16 light years away.
15:31GJ832C could be an Earth-like world, where conditions are always changing.
15:40The planet's orbit is so tight, it takes just 36 days to complete.
15:48Alien life must adapt quickly, as winter spreads across the planet once every month.
15:57The more we search, the more we find new bizarre alien worlds.
16:04One moon orbiting Saturn hides behind a thick orange atmosphere,
16:09its surface obscured from view.
16:14But a recent mission sent a probe down to the moon's surface.
16:20We got our first look at the surface of Titan, and what a shock, what an amazing sight.
16:26Hidden below its alien atmosphere, lies a world unlike any other in the solar system.
16:44This orange fuzzball is possibly the most alien world we have in our solar system.
16:51Titan, the largest moon of Saturn.
16:55Bigger than Mercury, it looks nothing like our own planet from space.
17:00But up close, Titan appears strangely Earth-like.
17:05Titan's atmosphere is mostly nitrogen, kind of an eerie similarity.
17:09It makes us feel like Titan is our twin planet out there.
17:14In 2005, scientists landed the Huygens probe on the surface of the moon.
17:22The images it beamed back showed totally unexpected geographical features.
17:31The probe revealed a secret beneath Titan's thick orange atmosphere.
17:36Something exceedingly rare in our solar system.
17:40A network of lakes right on Titan's surface.
17:45But what can stay liquid at 290 below zero?
17:50A sea of liquid methane.
17:53Methane takes the place of water here on Earth.
17:56This evaporates up and goes into Titan's atmosphere, rains out in other places, and then forms streams and river, which
18:02then flow into the lakes and start the cycle over again.
18:06This is Lake Powell in Utah.
18:09Steep cliffs surround a flooded valley.
18:13The landscape here mirrors the lakes and valleys on Titan.
18:20Ralph Lawrence develops space probes to explore Titan's lakes.
18:25This is such a good place to do our testing because the landscape here has a very branchy shape to
18:30the shoreline.
18:31That's the same as on Titan.
18:35Of all the worlds in the solar system, Titan is the one, apart from the Earth, that an unprotected human
18:40would survive the longest.
18:41You could hold your breath for a minute, and then after a while you'd freeze to death.
18:45But you'd last longer than anywhere else.
18:48Titan's methane seas could hold the key to life on this alien world.
18:55To find out more about them, we need the right technology.
19:02Today, Ralph tests a sonar probe.
19:06It's designed to scan Titan's seabed to build up a detailed map.
19:12Life as we know it requires liquid water.
19:15On Titan, it might be that the processes of life can occur in a non-water liquid in the seas
19:21of methane.
19:23We want to understand the three-dimensional structure of the seas on Titan.
19:27We can do that with sonar, just like we do on Earth.
19:31So this is an oscilloscope to let us look at the signal.
19:35This bad boy, real sonar transducer we would send to Titan.
19:40Ralph perfects the technology that will travel to Titan.
19:44His instruments must be extremely tough, small and light to survive on board a space probe.
19:52The sonar sends out a pulse of sound.
19:57And from the time it takes for the echo to come back, we can determine how deep the sea is.
20:04Space scientists like Ralph are discovering that Titan's geology is very similar to Earth's.
20:11With one huge difference.
20:15The Huygens probe has discovered that what looks like a rocky landscape is completely made of ice.
20:26Deep inside it, scientists found the engine that creates Titan's features.
20:34Huge pockets of ammonia-rich liquid water are under enormous pressure.
20:42Like magma on Earth, this supercool fluid can break through cracks in the moon's surface crust.
20:50And erupt in huge volcanoes, creating streams of icy lava.
21:01These ice volcanoes could have helped create Titan's mountains, valleys and seas.
21:09Titan has an amazingly complicated landscape.
21:12And we're just learning whether it was really made in the same way Earth was.
21:17Ralph's next probe to Titan will carry weather sensors and a mass spectrometer that will analyze the chemistry of the
21:24methane seas.
21:25But his sonar device will have to operate autonomously as it scans the sea bed.
21:30Well, that's working as well as predicted.
21:32The next step would be to integrate the sensor with a freely floating capsule and see how to build a
21:37profile as we drift across the sea.
21:42Titan is similar to the Earth, but really different.
21:46You know, it's based on methane and it's very cold and the atmosphere is different.
21:50And yet we think that conditions could be okay there for life to arise.
21:57Of all the alien worlds that orbit our sun, Titan is one of the most complex and intriguing.
22:07And one day, it could become the most habitable place in our solar system.
22:16In five billion years, our sun will expand into a red giant and incinerate Earth.
22:26But Titan will get less UV radiation from the dying sun.
22:33The dense, smoggy atmosphere will clear and allow sunlight through.
22:40The surface temperatures will rise and the ice will melt.
22:45The moon will become a primordial Earth for hundreds of millions of years.
22:51Plenty of time for life to emerge.
22:58Our solar system has revealed extraordinary worlds with hidden alien habitats.
23:04If these wonders exist so close to home, what mysteries might be orbiting our neighboring stars?
23:12I look up in the sky and no longer do I see points of light that are stars.
23:17I see solar systems.
23:20Pick a star, it more than likely has planets orbiting it.
23:24Could one of these distant alien worlds be just like Earth?
23:28I just don't remember, they will lose its way.
23:322 TIRESики
23:57Igor
24:01In 2009, NASA launched the $600 million Kepler Space Telescope to speed up the search.
24:13Before Kepler, we didn't know what fraction of stars had planets.
24:18Kepler has the biggest telescope mirror we've ever sent beyond Earth's orbit.
24:23Its mission? Hunt for planets that orbit distant stars.
24:28We didn't know whether there was enough debris left from star formation that would accumulate into planets.
24:37So far, Kepler has discovered almost 1,000 planets.
24:43Now we know, statistically, many, maybe even most, of the stars in our galaxy that you see when you look
24:50up at night are orbited by planets.
24:54Twenty-one of the planets scientists found orbit their stars at the right distance to have a climate similar to
25:01Earth.
25:02It may be oceans teeming with life.
25:08Astronomers have found one solar system that looks extremely promising.
25:15Kepler-186 is a star 500 light-years away from Earth.
25:22Scientists spotted five planets in its orbit.
25:26Four of these are too hot to have liquid water on their surface.
25:31The fifth is right in the sweet spot for life.
25:34It could be Earth's twin.
25:38But space telescopes cannot take pictures of this planet.
25:42The glare from its stars too bright.
25:47Pasadena, California.
25:50Engineers here are designing a unique spacecraft to see these hidden alien worlds.
25:56The scientists I work with are like Columbus, and I'm building his boat.
26:03Mark Thompson heads up NASA's Starshade Project.
26:08Flown into space, this huge sail unfurls like a giant umbrella and blocks out the light from the star.
26:16It's similar to putting your hand up against the sky so that we can see around the sun.
26:21All of the discoveries made so far have been indirect measurements.
26:26This allows us to see those planets directly.
26:33Today is a big day for Mark's team.
26:35The very first time they test a Starshade prototype.
26:40Okay.
26:41To create the perfect shadow, Starshade must fold out its foil petals into an exact circle.
26:47Christine, want to hit the switch?
26:52Okay.
26:53Motor's on.
26:56As it pulls free of the little clips, it will jerk here and there.
27:01Things that are unexpected happen.
27:07What was that?
27:09Right.
27:10We have a problem.
27:11It was crooked.
27:15That was it.
27:17Whoa-ho.
27:19Okay.
27:21Motor speed coordination problem.
27:26Okay.
27:27That's it.
27:32It deployed.
27:33We had some problems.
27:35One spoke broke and we had a snag in the line.
27:39And this is why we do these deployments.
27:41And we'll improve those features for the next one and be ready to go.
27:45This prototype is a scale model.
27:50The real Starshade will be twice as big.
27:55It will fly 23,000 miles away from its parent telescope to shade the target star.
28:04Planets that orbit distant stars will finally become visible.
28:12Star Shade could uncover the mysteries of some of the galaxy's strangest planets.
28:19Like Gliese 163c.
28:26It hugs a cool red dwarf star, which means temperatures could be right for life.
28:33But the star's massive gravity stops Gliese's spinning, which could do very strange things to the climate.
28:42Scorching one side into a barren desert, while the other side is frozen solid in icy, eternal darkness.
28:54Just a narrow, habitable strip, battered by violent storms, survives between the extremes.
29:04The prospect of finding life on another planet drives the Starshade team.
29:11All of our planning centers around about a 10-year time frame.
29:16The next big step is to put a giant blanket on it that makes it opaque,
29:20so that that distant starlight doesn't come through it.
29:23And we have a lot of work ahead of ourselves to get there.
29:27But today we had a successful test.
29:29They were one step closer to finding life on other planets.
29:33Not every new world that Starshade finds will support alien life.
29:39Planets that get too close to their star become hostile worlds.
29:46Forty light-years from Earth, planet 55 Cancri e almost touches a Sun-like star.
29:55Heat radiating off the star pushes temperatures on the planet to over 3,000 degrees.
30:04A layer of graphite covers the entire surface.
30:12And beneath this rocky blanket, extreme pressure has turned carbon into diamond.
30:20Scientists hunt for planets that are just like Earth.
30:26With liquid water on the surface.
30:30But Earth also hides a special secret in its atmosphere.
30:50Stars in the Milky Way provide light and warmth.
30:54That could support life on the planets that orbit them.
30:59But stars are also hostile.
31:02Just like our Sun.
31:04The Sun is the most violent, dramatic thing in our solar system.
31:10The Sun is a giant nuclear reactor.
31:14It belches streams of radiation towards Earth.
31:22A constant barrage of charged particles called the solar wind.
31:27They're actually high-energy particles.
31:30And when they hit organic compounds, it actually breaks up the molecules.
31:34They could actually break up our DNA, cause damage, mutations.
31:40The reason why life on Earth can survive this deadly onslaught hides 1,800 miles under the surface.
31:52The Earth's core is a molten ball of metal, nearly twice as big as the Moon.
32:01Immense pressure deep inside it forms a second core that is solid.
32:08As the two metal Goliaths grind past each other, they generate a huge magnetic field that seeps through the Earth
32:18and out into space.
32:24This gigantic force field engulfs our planet and shields us from deadly solar radiation.
32:33Without Earth's magnetic field, life would be impossible.
32:39The space science lab is perched here on top of a hill, overlooking the San Francisco Bay.
32:47Brian Walsh uses a network of five satellites called FEMIS to investigate Earth's magnetic field.
32:55We're looking at some of the downlinks with the FEMIS spacecraft.
32:58We only have a very small window each orbit when we're able to communicate with the spacecraft.
33:03The FEMIS satellites race through the very upper layer of the atmosphere.
33:09They orbit Earth every 23 hours.
33:13They have four 82-foot-long antennas that allow Brian's team to measure how Earth's magnetic field reacts to blasts
33:21from the sun.
33:23The typical length of one of these communication windows is about 50 minutes.
33:28And we'll be able to communicate with this dish here.
33:33The team has to download the satellite's data and check on its health.
33:40Right now we're actually entering our window of communication with FEMIS spacecraft.
33:44We're relatively close to overhead from Berkeley Ground Station.
33:48And this red shape around it is the area where we're able to communicate with the spacecraft.
33:53We should get all the data.
33:55It's fantastic. Great.
33:57For life to thrive on an alien world, it needs protection from its star.
34:03The same protection that we have on Earth.
34:06For decades we've thought that the Earth is kind of like the sun's punching bag and that when an explosion
34:11happens on the surface of the sun,
34:15all this material just goes screaming through the solar system outward and slams into the Earth and the Earth's magnetic
34:20field.
34:22And this is a bit concerning.
34:23We're kind of at the sun's whim.
34:26But very recently we found some very interesting measurements with the FEMIS spacecraft that show that the Earth actually has
34:33some protection itself.
34:38Earth doesn't just sit and wait for a solar punch.
34:42It has a preemptive weapon.
34:45As UV light hits the atmosphere, it creates a thin layer of charged gas.
34:53Earth's magnetic field squeezes this into a huge donut-shaped ring around the planet.
35:02When the sun whips up a solar storm, the highly charged particles in the ring start to shift.
35:09They gather into a massive tendril that reaches into space to meet the solar blast and slow the radiation.
35:20So we actually can fight back a bit. It's quite exciting.
35:25Life in the form that we know it wouldn't be able to survive without a magnetic field protecting it from
35:30radiation.
35:32Scientists think that Mars once had a life-supporting magnetic field as well.
35:39But four billion years ago, it disappeared.
35:42Mars may have been Earth-like before Earth was Earth-like.
35:46But unfortunately, the atmosphere was eroded away by the solar wind.
35:52Climate change on a catastrophic global scale.
35:56I can't imagine any life could have survived such a huge event like that.
36:01The sun also attacks the alien worlds in our solar system.
36:07But small moons like Europa rarely produce their own magnetic fields.
36:13How could life possibly exist there?
36:19Europa relies on something bigger for protection.
36:26Its parent planet, Jupiter, has a huge magnetic field that stretches three million miles from the planet.
36:40It's power rubs off on Europa and helps generate a small magnetic field around the moon.
36:51Earth has the key ingredients for life to flourish.
36:55A magnetic field, liquid water, and a breathable atmosphere.
37:02Could this magical combination exist on another planet in our own galaxy?
37:07Could intelligent life have evolved there?
37:11We're beginning to find answers to the question of not just whether there's life,
37:16but whether ultimately there might be civilizations out there, and where do we look for them?
37:22If these civilizations exist, how will we know?
37:41It used to be that when you'd go out at night and you'd look up in the sky,
37:45you had no idea if there were any planets out there orbiting those stars.
37:48Now we know many have multiple planets.
37:51They're solar systems just like ours.
37:53The chances are, life is everywhere throughout the universe.
37:58What are the odds that life exists outside of Earth?
38:02Stellar nurseries in our galaxy create new stars in alien worlds all the time.
38:11Our galaxy contains up to 400 billion stars with untold numbers of planets.
38:22And there are 100 billion galaxies in the universe.
38:28With numbers so astronomically high, the odds suggest that life is out there.
38:35And it may even be intelligent.
38:42There are probably many different variations.
38:44I think that reality is going to be much more fantastical than we can imagine.
38:51An intelligent civilization might even send a signal back to Earth.
38:59This is the SETI Institute, a giant telescope array listening for radio signals from alien worlds.
39:10SETI, it's an acronym.
39:12It just stands for the Search for Extraterrestrial Intelligence,
39:16looking for the kind of life that's smart, intelligent, the way humans are.
39:24Seth Shostak is the man in charge of the mission.
39:28You know, when I was a kid, I was really interested in movies about aliens.
39:32It's the same sort of interest as dinosaurs.
39:35A network of 42 small dishes work together to scan the heavens.
39:41So, wherever we point in the sky, we usually check out a few billion channels.
39:46Because, after all, E.T. never sent us an email saying,
39:49hey, this is what frequency you should listen at.
39:54Despite the fact that these things are only, what, six meters, maybe 20 feet across,
39:58they're incredibly sensitive.
40:00If you had a signal falling on the entire Earth of 1,000 millionth of a watt,
40:061 billionth of a watt, these guys could easily pick it up.
40:09And that's like a, you know, a remote control for your car door on Mars.
40:17If our galaxy's not adequate for your life demands,
40:21you know, there are 100 billion other galaxies we can see,
40:23and they've all got a similar number of planets.
40:25So, there's just literally an uncountable number of planets where life could have started up.
40:32Despite over 50 years of silence,
40:35Seth remains confident that one day, they will make contact.
40:40If we were to pick up a signal,
40:41it would become the most interesting science story probably of all time.
40:50The discovery of life beyond the solar system will destroy our cosmic loneliness.
40:57You know, that feeling that we have when we look up into the sky and we feel very small.
41:01The knowledge of other living things out in the galaxy is going to have a major impact
41:06on how I view my own self and my relationship to other humans on this planet.
41:13One of the things you really have to get your mind around is how connected we are to the Earth.
41:17Our chemistry, our biology matches this place.
41:20If we go to another planet, we might not be even able to eat the plants.
41:24So, you have to realize just how much of an Earth creature you are,
41:28and use that to be humble when it comes to finding and interacting with life outside the Earth.
41:35That's going to be a revolution in thinking for the humans who exist at that time.
41:39But that generation of people are going to be quickly replaced by a new generation of people
41:44for whom alien life is considered normal.
41:48Our search for alien worlds takes us to the edge of our observable universe.
41:56We will find a new Earth twin throughout our galaxy.
42:04And we're scouring strange moons in our own solar system.
42:14If there are alien life forms out there, it's just a matter of time before we find them.
42:23Unless they find us first.
42:26Unless they find us first.
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