New discoveries have revealed thousands of exoplanets beyond the solar system, and some resemble earth enough that one could be a new home for humanity; with cutting-edge technology, finding the perfect one is the scientific challenge of the age.
Thanks for watching. Follow for more videos.
#cosmosspacescience
#howtheuniverseworks
#season7
#episode9
#cosmology
#astronomy
#spacetime
#space
#nasa
#newearth
#findingnewearth
#exoplanets
#newhomeforhumanity
Thanks for watching. Follow for more videos.
#cosmosspacescience
#howtheuniverseworks
#season7
#episode9
#cosmology
#astronomy
#spacetime
#space
#nasa
#newearth
#findingnewearth
#exoplanets
#newhomeforhumanity
Category
📚
LearningTranscript
00:00Earth.
00:07The cradle of humanity throughout our existence.
00:17But it won't be forever.
00:22All it would take would be one giant meteorite to wipe us off the face of the Earth.
00:30It's not just meteors.
00:36Our planet will change.
00:39Our planet could freeze over or it could heat up.
00:43And our sun will eventually die.
00:47We are actually near the end of habitability of Earth.
00:52To survive in this universe, we need an insurance policy.
01:00To colonize other worlds.
01:04Having multiple planets which are colonized is really in our interest for our own survival.
01:10So, can we find a new home in the galaxy?
01:14Can we find Earth 2.0?
01:20Can we find more?
01:21That's the real deadline?
01:22How is life?
01:39For centuries, we only knew of the handful of planets in our own solar system.
01:49Now, astronomers are finding thousands of new worlds around alien stars, exoplanets.
01:58We are discovering exoplanets by the bucketful.
02:04There are as many planets out there as there are stars, and there are hundreds of billions of stars in the galaxy.
02:16But out of billions of exoplanets, are there any that could offer new opportunities for humanity to thrive and provide sanctuary in a dangerous universe?
02:31Is there an Earth 2.0?
02:34Is there an Earth 2.0 out there?
02:39That would be truly amazing.
02:49August, 2016.
02:53Astronomers announced that Earth 2.0 could be closer than anyone ever expected.
02:59A planet orbiting the sun's nearest stellar neighbor.
03:07The red dwarf, Proxima Centauri.
03:13So it turns out that our nearest star neighbor has an exoplanet.
03:19It's only about four light years away.
03:21So that means that it's actually potentially possible for us to get there and to explore it.
03:28Scientists name the planet after the star.
03:32Proxima Centauri B.
03:34Or Proxima B for short.
03:36A world that appears to be a lot like Earth.
03:45From the way it's tugging on the star, Proxima Centauri, we know that it has 1.3 times the Earth's mass.
03:51But it's roughly the same size as the Earth.
03:58Of the exoplanets we know about, most are uninhabitable gas giants, like Jupiter.
04:05Proxima B is a rare find, an Earth-sized planet.
04:09But an Earth-sized planet might not be Earth-like.
04:15A true second Earth must also be the right distance from its star.
04:23The habitable zone, or some people call it the Goldilocks region,
04:27is a distance away from the star,
04:31where you're not so close where you're going to burn up and evaporate all of your liquids.
04:36And you're not so far away where you're frigid and cold.
04:39So it's that special region where it's just, just right.
04:45Does Proxima B lie in this region?
04:49Could it have liquid water?
04:53Proxima Centauri B orbits its star once every 11.2 days.
04:57So compare that to the Earth, which goes around the Sun, once every 365 days.
05:02That's because the planet is much, much closer to the star than the Earth is to the Sun.
05:09Earth orbits 93 million miles from the Sun.
05:18Proxima B orbits 20 times closer, under 5 million miles from its star.
05:23You might think that Proxima B should be, you know, really a fried world, a burnt-out husk, if you will.
05:33But Proxima B's Sun is very different than ours.
05:40At just over 5,000 degrees Fahrenheit, it's half as hot and roughly eight times smaller.
05:51An M-class red dwarf star.
05:55An M dwarf, the Proxima B is around, is much less bright, much less hot.
06:01So you can orbit much closer to that star and be at the same temperature that we are here on Earth.
06:12Proxima B's tight orbit around the red dwarf could make the planet habitable.
06:16But it would be very different from Earth.
06:23The star dominates the sky, lighting any oceans and mountains with an alien red glow.
06:32So Proxima B may be the Earth 2.0 that we've been looking for.
06:41But in 2017, the dim red dwarf star erupts in a way that's unlike anything we've seen before.
06:50Blasting the planet with radiation.
07:00A mega flare.
07:02They're like solar flares, but they can be much more powerful.
07:06In fact, they can outshine the star itself.
07:10Our Sun releases powerful solar flares when its magnetic field becomes tangled.
07:17But the mega flare is ten times stronger than our Sun's strongest flares.
07:29On an M dwarf star, that magnetic field can get a lot more tangled than on our own Sun.
07:35That means that when a flare happens, it can release a lot more energy.
07:42Scientists believe that mega flares like this are planet killers.
07:47Radiation tears the atmosphere from the planet.
07:55And these mega flares hit Proxima B roughly once every year.
08:03Red dwarf stars are incredibly temperamental.
08:07They are not good parents to their planets.
08:11So if Proxima B did have an atmosphere at one point, it would have been stripped away by one of these violent outbursts.
08:20Leaving Proxima B dangerously exposed to space.
08:28An atmosphere dampens the temperature gradients between light and shadow.
08:33So in sunlight, it is just burning hot, but right next door in a shadow, it is freezing cold.
08:41Without an atmosphere, Proxima B would be a barren wasteland blasted by intense radiation from its star.
08:53Completely uninhabitable.
08:55Proxima B, perhaps best shot at finding Earth 2.0 so far, is actually a dried out husk of a world that has lost its atmosphere,
09:08maybe lost any water that it also harbored, simply by being that close to its parent star.
09:15Proxima B may be the nearest exoplanet, but it's not the only option.
09:28The future of humanity may lie in an incredible star system just 40 light years away.
09:36We've just found a really exciting system where there's not just one chance to have a new Earth, but seven.
09:45In an unforgiving galaxy, finding Earth 2.0 could be the difference between extinction and survival.
10:08It's a pretty wild place out there.
10:15Our planet's not going to be here forever, and it would be wonderful if we could find a place like it that we could live.
10:26The future of humanity lies on an alien exoplanet.
10:31The question is, where?
10:332016.
10:40Astronomers scan the skies with the new Transiting Planets and Planetesimals Small Telescope, or TRAPPIST.
10:51They look for the flickering of a star, caused by the silhouette of a planet.
10:57The planet can pass in front of the disk of its star once per orbit, causing a little mini-eclipse, a little dimming temporarily in the light of the star.
11:09Scientists spot the dimming of a nearby red dwarf star just 40 light years from Earth.
11:15The first alien system detected by the telescope, the incredible TRAPPIST-1 system.
11:27The TRAPPIST-1 discovery was a really great bang for our buck, in a sense, because we found seven exoplanets all at once.
11:37But are any of these seven planets actually habitable?
11:44With the worlds of the TRAPPIST-1 system, there's probably a range of climates.
11:48The innermost ones are probably very hot.
11:51You might even be looking at lava worlds.
11:54Farther away, there are probably worlds of ice.
11:57But the middle planets, D, E, and F, are all prime candidates.
12:08It's exciting to think that three of the planets orbiting TRAPPIST-1 are in the habitable zone,
12:13are at the right distance from that star to have liquid water on their surface.
12:16And one planet stands out as a new Earth, orbiting just 2.7 million miles from the star, TRAPPIST-1e.
12:34The composition of TRAPPIST-1e suggests that it could have a pretty significant iron core, kind of like the Earth does.
12:41There's a potential there for a very powerful magnetic field.
12:46Like Earth, TRAPPIST-1e could host a protective magnetic field,
12:52deflecting the harsh solar winds and powerful outbursts that strip away atmospheres.
13:00So a magnetic field is a good thing.
13:02It's a kind of a protection from the evil forces of the star that you're orbiting around.
13:08And unlike Proxima Centauri, the TRAPPIST-1 star appears unusually quiet.
13:14TRAPPIST-1 is actually a very old, much calmer star and doesn't undergo a lot of these huge flares like Proxima Centauri does.
13:23And so it's a somewhat, perhaps, better system to look for an Earth-like planet, an Earth 2.0.
13:28The data suggests that TRAPPIST-1e could have vast oceans, a protective atmosphere, and habitable temperatures.
13:41But living here would be nothing like living on Earth.
13:57The thing to keep in mind about the TRAPPIST system is that it's very unlike our own.
14:01The planets are much closer in.
14:03So because they're closer in, their orbits are faster and smaller.
14:08On TRAPPIST-1e, an entire year takes just six Earth days.
14:15Can you imagine you're just basically tearing your calendar days off, day after day after day, really quickly?
14:20Your birthday would be today, and then tomorrow.
14:23Happy birthday again!
14:24Wedding anniversaries.
14:25You're constantly forgetting your wedding anniversary.
14:28And it would be hard.
14:29And on this strange and alien world, explorers would witness sights unlike anything seen before.
14:40In a lot of ways, it really is sort of a science fiction sky, the kind of things that are envisioned in movies.
14:46You could look up and see the other planets in your sky, much like how we can see our own moon.
14:52You could physically resolve features on the surface, such as continents, with your own eyes.
14:59But could this planet be too good to be true?
15:04So we could have a potentially habitable planet that's really close to its star.
15:10But other issues arise when you have a solar system that's that compressed.
15:14And one of those is the potential for tidal locking.
15:21Orbiting just a few million miles from the star, TRAPPIST-1e is likely tidally locked.
15:29With one side facing the star forever.
15:35So you could imagine a situation where, gosh, it's constant day, and it might just produce something that's like a scorched earth.
15:42Kind of like what we see behind me.
15:44But on the other side, it is constant night.
15:47And so in that case, it might just be like a frozen wasteland.
15:50And TRAPPIST-1e's problems get even more extreme.
15:57If you have a permanent day side and a permanent night side, the night side of the planet is going to get so cold that everything just freezes out, including the atmosphere.
16:06The gases of TRAPPIST-1e's atmosphere could freeze into solid ice on the frigid night side of the planet.
16:19And the gases on the day side burn away.
16:23The atmosphere thins and eventually disappears.
16:31And TRAPPIST-1e ends up completely inhospitable.
16:36So even though we found maybe a perfect planet around a star, the type of star and where it's orbiting can have a really important effect as to whether or not that planet might be habitable.
16:51Despite its apparent potential, our future is not in the TRAPPIST-1e system.
16:57The search for truly Earth-like planets continues.
17:03In the TRAPPIST-1e system, we find a very Earth-like world, but the star as orbiting is not very Sun-like.
17:11So what we should be looking for, perhaps, is an Earth-like planet around a Sun-like star.
17:19To find Earth 2.0, we need a Sun 2.0.
17:27The Milky Way.
17:47Home to hundreds of billions of stars.
17:50Ranging from dim, explosive red dwarves.
17:59To short-lived, blazing giants.
18:08But in the middle are stars like our Sun.
18:11Strictly speaking, if we really want Earth 2.0, we need to look for planets around stars like our Sun.
18:21Stars like our Sun are calm and stable with long lives.
18:25And the habitable zone lies far enough away that planets avoid tidal locking.
18:35We stand a much better chance of colonizing a planet around a Sun-like star.
18:41We're hunting for planets in the habitable zone of stars like our own Sun.
18:47And we have found worlds there.
18:50Worlds like Kepler-452b, an exoplanet 1,800 light-years away, orbiting the same type of star as our Sun.
19:08You really couldn't ask for a more Earth-like orbit around the star.
19:14The year is about 385 days.
19:16We're 365 days.
19:18This really is very much like the Earth.
19:21The planet orbits its star at roughly the same distance as the Earth orbits the Sun.
19:29And could be very much like home.
19:32Kepler-452b is in the habitable zone of its star.
19:39So if there is liquid water there, there could be oceans and lakes and rivers and streams and blue skies and cloudy days.
19:51Sounds nice, but Kepler-452b is a lot larger than Earth.
19:56Kepler-452b is a great Earth 2.0 candidate, but it's sort of like Earth on steroids.
20:09This world is about five times more massive than our own planet and about 60% wider.
20:18Scientists call large worlds like Kepler-452b super-Earths.
20:26These worlds are maybe one and a half or two times the size of the Earth, with maybe as much as ten times the mass.
20:35Could this super-sized Earth-like planet be our second home?
20:41A planet like this seems to meet a lot of our standards for an Earth 2.0.
20:46It's around a star like our Sun.
20:48It's smack dab in the middle of the habitable zone.
20:51The problem is there are other factors at play.
20:54One of those is simply the mass of the planet.
20:56Kepler-452b's size has an extreme effect on its gravity.
21:09Because of its incredible mass, the gravity on the surface is about twice what we feel here on the Earth.
21:17That extra gravity would make colonizing the planet difficult.
21:24Just about any chore you can imagine doing that you don't like doing on the Earth, you're going to like it even less on a planet like that.
21:30When the garbage can weighs twice as much as it does here on the Earth, that's not going to be very much fun.
21:36Maybe LeBron James and I will be okay, but normal humans, I'm not so sure.
21:41And we could be stuck on the planet's surface.
21:49If you landed on the surface of one of these super-Earths, it'd be pretty easy to get down onto the surface, but it would be very difficult to get back up.
21:56It's already incredibly difficult for us to leave the Earth.
22:01Think of our giant engines and rockets, these incredible miracles of engineering that we need to blast off.
22:08You need twice that to get off of Kepler-452b.
22:11And to make matters worse, Kepler-452b's atmosphere is thought to be radically different from Earth's.
22:24In some sense, how big the planet is, how massive it is, will determine what its atmosphere is like.
22:30If you have a lot of mass and a lot of gravity, you can hold on to a lot of air.
22:35You can have a much larger atmosphere, much thicker, much denser, and higher pressure at the surface.
22:41A thick atmosphere could trap heat from the star.
22:48Surface temperatures become ferociously hot, and crushing pressures make the surface completely uninhabitable.
22:57So it's possible this planet has a very thick atmosphere that's become more of a runaway greenhouse effect.
23:03The planet's gotten hotter and hotter over time.
23:05Maybe instead of finding an Earth 2.0, what we've found is a Venus 2.0.
23:11Super-Earths may have an appealing name, but their intense gravity would make them difficult to live on,
23:22and we could not survive in their thick atmospheres.
23:26So far, all the worlds we've found have turned out to be uninhabitable.
23:39But what if our new home is not a planet?
23:44Earth 2.0 may not be an exoplanet at all.
23:48It might be an exomoon.
23:50The Earth 2.0 may not be an exoplanet at all.
24:09We live in a cosmic shooting range,
24:13where planets die every day.
24:17But backup planets like our own seem almost impossible to find.
24:25Have we been looking for the wrong thing?
24:30I think there's a pretty good chance that Earth 2.0 might not be a planet per se,
24:35but actually a moon of a giant planet.
24:38The exciting thing about an exomoon is that they could potentially be habitable.
24:42So is it possible that as we look at different solar systems,
24:46the real analog for Earth 2.0 will turn out to be an exomoon?
24:572017.
24:59The Kepler telescope scanned a sun-like star 8,000 light years away.
25:05And Professor David Kipping and his team watched the transiting exoplanet.
25:12Kepler 1625b.
25:17Kepler 1625 was one of the many thousands of planets discovered by Kepler.
25:23But what made it different from our perspective as a moon hunter was that this is a planet which was Jupiter-sized,
25:31far away from its star, and apparently on a near circular orbit.
25:35So everything that we want for finding exomoons.
25:42The exoplanet Kepler 1625b is an uninhabitable gas giant, like Jupiter.
25:50But it is in the habitable zone.
25:55And that means its moons would be too.
26:02Unfortunately, these exomoons are incredibly hard to see.
26:10The way that Kepler finds exoplanets out there, it really does relate to the size of the planet.
26:16And for moons, it's much, much more difficult because it's smaller, so it's harder to detect.
26:21The largest moon in the solar system is Ganymede around Jupiter.
26:25It's about 40% the size of the Earth.
26:27And we really very rarely detect planets that small.
26:31So, of course, looking for exomoons is going to be very, very challenging.
26:36In 2018, the team recruited the powerful Hubble Space Telescope
26:47and used the data to hunt for the tiny silhouette of any moons.
26:54If you have an exomoon orbiting a planet,
26:56sometimes it's going to lead the planet when it transits the star,
26:59and sometimes it's going to trail behind as it transits the star,
27:03and you see a little bump in the transit dip itself at different places.
27:09And the team detected the signal.
27:13Not one, but two objects orbiting together.
27:18Confirmation of the first exomoon ever discovered.
27:33It was an amazing discovery.
27:35I've been looking for exomoons my entire career.
27:38For 10 years, we've been in this quest to try and find these things.
27:42This discovery, this announcement, was absolutely remarkable.
27:47Not only does it mean that we might find Earth twins everywhere in the Milky Way,
27:52but it gives us something to strive for for human exploration.
27:56On this alien exomoon, the skies would be nothing like Earth's.
28:06Visually, I think it would be an absolutely stunning place to be.
28:09You look up in the sky and you see this ringed planet looming huge in the sky.
28:14A world that could be like Earth, only orbiting another planet.
28:30But don't pack your space suit just yet.
28:33Even though the planet and the moon are potentially the right distance away from the star
28:38that we might imagine there being liquid water on the surface,
28:41both the moon and the planet are likely gaseous objects
28:45with no solid surface to speak of.
28:50Although the moon probably isn't habitable,
28:52it is an important step for finding worlds like our own in the galaxy.
28:57If we find exomoons around exoplanets,
29:02that potentially hugely increases the number of habitable worlds that are out there.
29:07We just need more accurate measurements,
29:09and then all of a sudden the universe is going to be full of exomoons.
29:18But these worlds need to be more than just Earth look-alikes.
29:22Everyone gets very excited when we find Earth-like planets around other stars.
29:28But Earth-like kind of just means how big it is
29:31and whether it can support liquid water, where it is in relation to its star.
29:35All of that is great, but it's just not enough.
29:43A planet's composition could be make or break for our new home.
29:47The difference between the perfect world and a ticking time bomb.
29:56The hunt for Earth 2.0 is still on.
30:08We've examined intense Red Dwarf systems,
30:13The hunt for Earth 2.0 is still on.
30:20We've examined intense red dwarf systems,
30:24massive super-Earths,
30:27and alien exomoons.
30:31But so far, there's no place like home.
30:36There are all these criteria we have to tick off.
30:39A sun-like star,
30:40an orbit that puts it at about the right temperature,
30:44a solid surface,
30:45something that could retain an atmosphere.
30:49But a planet that appears Earth-like on the outside
30:52may not be Earth-like on the inside.
30:59One of the things that makes our world so unique
31:02is its plate tectonics,
31:03and that actually regulates our climate.
31:05The Earth's climate depends on cycles of materials,
31:12like carbon dioxide and water.
31:15Molecules move between the Earth's molten interior
31:18and the surface
31:19through active plate tectonics
31:22and volcanic eruptions.
31:25These cycles help to regulate the temperature
31:29and composition of the Earth's atmosphere.
31:31If we were to find another Earth-like planet out there
31:37and it had geologic activity,
31:39that means that at least it has the means
31:41to sustain the carbon cycle
31:44and all of these natural phenomenon
31:46that makes this planet habitable and sustainable.
31:50How can we know what's happening inside a planet?
32:00A clue can be found
32:01in vast ranges across our world.
32:05Mountains.
32:06These topographical features
32:16are an indicator that the planet is alive
32:19and there is still processes happening
32:21underneath its surface.
32:27Mountain ranges are created
32:29when a planet's tectonic plates collide.
32:31And even though exoplanets are light-years away,
32:37astronomers could work out
32:39whether their surfaces are smooth
32:42or covered in peaks.
32:47Those mountain ranges are poking out
32:49and depending on which rotation the planet is in,
32:53the planet will appear very slightly bigger
32:55or very slightly smaller
32:57depending on the silhouette which is being cast.
33:01These tiny changes in light
33:06could be the sign that an exoplanet
33:09is healthy and active.
33:13But we can only use this method
33:15when a planet is in front of its star.
33:19What if astronomers could use starlight itself
33:23to determine the geology of a planet?
33:27We think that planets form
33:29at roughly the same sort of time
33:31that stars form
33:32and they all form from this same
33:34giant cloud of material.
33:39And so if you measure the composition of a star
33:41then it seems reasonable to take those values
33:44and assume they're somewhat similar
33:45for the planets as well.
33:50Astronomers can work out
33:52what chemical elements are present in the star
33:55by splitting its light
33:57into different wavelengths.
34:00And any planets around that star
34:02will have a similar chemical composition.
34:06Composition is actually a really important part
34:09of whether or not it's actually going to be habitable.
34:12The composition really is its geology.
34:14Rocky exoplanets are all made from the same basic ingredients.
34:23Chemical elements like oxygen, silicon, and aluminum
34:27change the balance of ingredients
34:30and you get very different planets.
34:33If we have some idea of the composition of a rocky planet
34:39we can actually use that to give us clues
34:42as to whether a world has or doesn't have plate tectonics.
34:46New research indicates that exoplanets
34:52with too much silicon and sodium
34:54form different types of rock
34:56than those on Earth.
34:58Creating rigid planets
35:00where plate tectonic stall
35:03and carbon dioxide
35:04builds up
35:05with devastating consequences.
35:10Without active geology
35:12we end up with maybe a Venetian atmosphere.
35:14That means there's a runaway greenhouse effect.
35:18It's gotten hotter and hotter
35:19gases are baked out of the rocks
35:21there's no way to actually rain them back out
35:23not a good place for life at all.
35:29At worst
35:30the planet becomes a pressure cooker
35:33waiting to explode.
35:36If we change the composition of a planet
35:38it affects its tectonic system
35:40that entirely changes how a planet loses heat
35:42and the heat builds up
35:44and builds up
35:44and builds up
35:45and then maybe there's a catastrophic overturn
35:47of the crust.
35:58The solid crust of the planet collapses.
36:05Oceans of lava bubble up
36:07and the greenhouse atmosphere
36:09boils the surface.
36:13A violent end
36:14to a potential new home.
36:20Clearly
36:21you need to know about
36:22the composition of those planets
36:23before you can start making statements
36:25about how habitable
36:26those worlds truly are.
36:28But
36:31there's something else
36:32that a planet needs
36:34to be Earth-like
36:35an invisible shield
36:37that protects it
36:38from the dangers of space
36:40providing warmth
36:43and life-giving water
36:45and atmosphere.
36:47The hunt for Earth 2.0
37:07has turned up plenty of planets
37:09but for a planet
37:11to be like Earth
37:13it has to check
37:14a lot of boxes.
37:17If you're really looking
37:18for Earth 2.0
37:20then you're going to have
37:21to find a planet
37:22that's the same mass
37:23and size as Earth
37:24orbiting a sun-like star
37:27at about the same distance
37:29with a similar atmosphere
37:31and a lot of surface water
37:33that's in liquid form.
37:35Good luck.
37:36And on the list of requirements
37:42an exoplanet's atmosphere
37:44is critical.
37:47It protects the planet
37:49from huge temperature swings.
37:51It protects the planet
37:52from small asteroid impacts.
37:54It protects the planet
37:54from dangerous radiation
37:56from space
37:56and from the star.
37:58It is almost literally
37:59a shield around the planet
38:00protecting us
38:01from outer space.
38:02But it also has to be
38:05the right kind
38:06of atmosphere.
38:12Get it wrong
38:13and a planet
38:14can have crushing
38:15boiling conditions
38:17on the surface.
38:20Look at our own solar system.
38:22The sun's habitable zone
38:24includes three different planets
38:25Venus, Earth, and Mars.
38:27But Mars has a thin atmosphere
38:28and is too cold.
38:30Venus has too thick
38:31of an atmosphere
38:31and is too hot.
38:32We're the only planet
38:33that happens to be
38:34just right.
38:41So far,
38:42astronomers have mostly
38:43had to guess
38:44if these exoplanets
38:45have atmospheres.
38:48But now,
38:49we're looking for them
38:50directly.
38:53Searching for
38:54Earth-like atmospheres
38:55around Earth-like planets.
38:57This is incredibly
39:01hard to do.
39:03So in order to
39:04look at the details
39:05of these atmospheres
39:06and the glare
39:07of the star
39:07requires incredibly
39:09precise technology
39:12and precise measurements.
39:16Astronomers detect
39:17atmospheres
39:18by watching a planet
39:20pass in front
39:21of the star.
39:22A small fraction
39:25of light
39:26shines around
39:27the edge
39:28of the planet
39:28and through
39:29the atmosphere
39:29where molecules
39:32like water,
39:33hydrogen,
39:34and carbon dioxide
39:35absorb particular
39:37wavelengths of light
39:38from the star.
39:41If we can see
39:43the light
39:43of the star
39:44shining through
39:45around the planet,
39:46we can maybe
39:47deduce some information
39:48about does it
39:49have an atmosphere?
39:50What are the properties
39:51of that atmosphere?
39:52How hot is it?
39:53What's it made out of?
39:55That's how we'll be
39:56able to determine
39:57if things in the
39:58atmosphere might indicate
40:00that the surface
40:01is hospitable to life.
40:05So far,
40:06we haven't seen
40:07any exoplanets
40:08with atmospheres
40:09that we could live in.
40:11But that's about
40:12to change.
40:13Scientists around
40:21the world
40:22are working
40:23on the next
40:23generation
40:24of telescopes
40:24to revolutionize
40:26exoplanet astronomy.
40:29We've got some ideas
40:30and some telescopes
40:31that are going
40:32to be built
40:32probably in the next
40:33couple of decades
40:34will be big enough,
40:36will be sophisticated
40:37enough
40:37to be able
40:38to see this sort
40:39of thing.
40:40missions like
40:42the James Webb
40:43Space Telescope.
40:46Seven times
40:48more powerful
40:48than Hubble.
40:50It should allow us
40:51to see the
40:52atmospheres
40:53of planets
40:53across the galaxy
40:55and be a tool
40:57that finally
40:58finds
40:59a second Earth.
41:00The key things
41:03we'd be looking
41:03for in these
41:04atmospheres
41:05are in the
41:05infrared part
41:06of the
41:07electromagnetic spectrum
41:08which is where
41:09Webb is designed
41:10to work.
41:12The James Webb
41:12Space Telescope
41:13is, I believe,
41:14going to be
41:15the next really
41:16critical mission
41:17to help us
41:19in our search
41:20for a potentially
41:22Earth-like planet.
41:27We're still
41:27searching
41:28for that perfect
41:29Earth-twin.
41:32And every day
41:33we get closer
41:36to finding it.
41:3830 years ago
41:40we had
41:40zero
41:41exoplanets.
41:43Today
41:44we know
41:44of thousands.
41:46With the next
41:47generation
41:47of instruments
41:49we're going to
41:49uncover
41:50tens of thousands,
41:52hundreds of thousands,
41:53even millions
41:55of exoplanets.
41:56all with the
41:58ultimate aim
41:59of leaving
42:00Earth,
42:01a civilization
42:02spread
42:03across the stars.
42:06One of the things
42:07I love about
42:08being a human
42:08is the fact
42:09that I'm born
42:09with this curiosity.
42:11This curiosity
42:12drives us
42:12to explore.
42:13Explore Earth,
42:15explore our solar system
42:16and beyond,
42:17into the galaxy.
42:18We'll be learning
42:19about these planets
42:20for a long time.
42:22We have just
42:23started this journey.
42:24We'll be learning
42:27more.
42:36We'll be learning
42:36more.
42:38We'll be learning
42:38more.
42:38All of the things
42:39we learn
42:39and beyond,
42:40we'll be learning
42:40and more.
42:40We'll be learning
42:41more.