00:00If humanity were forced to leave Earth and settle on another planet, where would we laugh?
00:07Mars appears to be the most promising planet, and it is close to Earth.
00:12But surviving there, good luck.
00:16Mars would freeze you, suffocate you, and atomize your DNA with cosmic radiation.
00:21and would shatter your dreams of colonizing under a dusty red sky.
00:26This is not a second Earth, it's a death trap in slow motion.
00:33Surely there must be another place where we could settle.
00:37Today, we're going to explore six of the most promising exoplanets.
00:42and see which one could become a true Earth 2.0.
00:48And to begin, let's head to the planet closest to Earth, Proxima Centauri B.
00:54Located just 4.24 light-years away, this exoplanet's orbit lies within its star's habitable zone.
01:02In the event of a cosmic catastrophe, such as the explosion of our Sun and the annihilation of the solar system,
01:09Proxima Centauri B could be an ideal escape route.
01:13Right?
01:14Don't get carried away.
01:16Four light-years is quite a distance.
01:18If you had a spaceship capable of traveling at the speed of light,
01:23It would take you a little over 4 years to get there.
01:27And let's be honest, you don't have that kind of technology, do you?
01:31The fastest object ever built by humankind is NASA's Parker Solar Probe.
01:37which travels at approximately 700,000 km/h.
01:40You cannot travel in this probe, as it is not designed to carry passengers.
01:45But if that were the case, it would take you approximately 6,500 years to reach your destination.
01:52Not practical at all.
01:53Space is extremely vast, and traveling from one planet to another takes a lot of time.
01:59Let's just say that there have been enormous advances in the fields of engineering and cryogenics.
02:03have finally allowed you and your crew to reach Proxima Centauri B.
02:09And then, you are on the verge of building a whole new civilization.
02:15The first thing you'll notice after landing is how dark and red your new sun is.
02:25What is the name of this star?
02:27Proxima Centauri, a red dwarf seven times smaller and hundreds of times less luminous than our sun.
02:34Proxima Centauri B is tide-locked to its star, meaning one side is always facing Proxima Centauri
02:44and that the other side is in constant darkness.
02:49Daytime temperatures there are hot, between 40 degrees and 100 degrees.
02:54And what about the nighttime?
02:55Well, it's very cold there, with minimum temperatures around minus 150 degrees.
03:03But you're clever and you've studied your course well.
03:06You land in the planet's Terminator, an area between constant daylight and endless night.
03:13And the temperatures there are mild.
03:15Your thermometer is showing a temperature of 15 degrees.
03:19That's a good start.
03:19As you begin to explore the planet, the ground creaks beneath your feet.
03:25The wind blows dust into the air.
03:28But you are not worried.
03:29You wear a pressurized suit to keep you protected from the wind.
03:33However, the atmosphere there is unbreathable.
03:36There is far too much carbon dioxide and almost no oxygen.
03:40If you take off your helmet, it's all over for you.
03:43You now need to build a shelter.
03:46But the problem with red dwarf stars, like Proxima Centauri,
03:51The problem is that they are unpredictable and can send huge bursts of X-rays and ultraviolet rays in your direction at any moment.
03:59The establishment of a solar storm shelter will therefore be a priority.
04:06After a week, your crew has set up a basic habitat and moved a ton of earth.
04:11You used a good layer of it to cover the floor of your home for extra insulation.
04:18This is where you will sleep, eat and survive for the next few weeks.
04:23For electricity, you will install wind turbines to take advantage of the breeze from Proxima Bay.
04:28And if you hear an alarm sound, run to the radiation bunker you dug into the ground.
04:34There, you will be safe until the star calms down.
04:36By the end of the first month, you will have built a second module where you will have created a small greenhouse.
04:46You grow potatoes, seaweed, maybe even a little kale there.
04:52Not a banquet, but enough to satisfy the taste.
04:55The first two months here will be devoted to a lot of engineering and strict rationing.
05:00But soon, you'll be able to venture a little further and start to really explore the planet.
05:07You will even be able to name the first landforms of this planet.
05:12Twilight Spiers, Eco-Cratzer, Flatten Ridge.
05:16This last one is a tribute to Chase.
05:19He sleeps all the time.
05:20By the end of the first year, you will finally be settled on this planet.
05:29You will have everything you need to live there reasonably comfortably.
05:33You will have access to living quarters, a laboratory, an electrical network, a radiation shelter and a greenhouse.
05:41Your menu will expand beyond kale and potatoes.
05:44Your camp is anything but idyllic; it is dusty and constantly threatened by intense solar flares.
05:51But it works.
05:52You succeeded.
05:53You live in a ribbon of twilight between fire and ice.
05:58One step too far to one side or the other, and you'll die.
06:01But you're still here.
06:03You still won't be able to remove your helmet or your spacesuit.
06:07The air here is still unbreathable.
06:10But you intend to stay.
06:12Hashtag Planet Goals.
06:14Your colony is now a great success.
06:21She has grown and evolved.
06:23There are people everywhere who have spent centuries using oxygen generators
06:27to convert carbon dioxide into oxygen and make the atmosphere breathable.
06:32At least for short periods of time.
06:35Huge solar flares are always a threat.
06:38But with bunkers all around the colony, everyone knows what to do in case of an alert.
06:44Unfortunately, your generation of colonists was severely irradiated by the star.
06:50Even if you have tried to avoid it, radiation still affects the population.
06:55That's why you mostly stay within your habitat rather than going out to explore the planet.
07:00One day, humans would become too numerous for the habitat and would have to expand beyond the Terminator.
07:08They should be able to adapt to life in extreme cold or unbearable heat.
07:12And this is not the life they imagined when they left Earth.
07:20Although Proxima B has many advantages, let's explore other worlds, such as TRAPPIST-1E for example.
07:27This exoplanet is located 40 light-years from Earth, and is only slightly smaller than our blue planet.
07:38TRAPPIST-1E orbits around an ultra-cool red dwarf star called TRAPPIST-1.
07:44And it has six other Earth-sized neighbors, although only three are located in their star's habitable zone.
07:51Fortunately, TRAPPIST-1E is located in the Goldilocks Zone, which means it could have liquid water on its surface.
08:00You are about to set foot on this extraterrestrial surface and make it your new home.
08:10You have just landed on TRAPPIST-1E, the most Earth-like planet in the entire neighborhood.
08:16And you are full of hope.
08:18By setting foot on this extraterrestrial soil, you will see the other six TRAPPIST planets in the same way that you see the Moon from Earth.
08:26You will also notice the faint sun hanging in the sky.
08:31Not at all like our Sun.
08:33It's TRAPPIST-1.
08:35This star represents only 9% of the mass of our Sun, and has a luminosity hundreds of times weaker.
08:41On TRAPPIST-1E, you will live in an endless twilight.
08:45The gravity here represents approximately 90% of Earth's gravity.
08:51So, when you walk, the slightly lower gravity would make your movements strangely graceful.
08:59Just like on Proxima Centauri B, the best place to land here is the Terminator area.
09:04Because yes, TRAPPIST-1E, too, is locked by tide to its star.
09:10And you don't want to burn on its daytime side, or freeze on the bare side.
09:15Temperatures in the Terminator can be cool, but bearable, a few degrees above 0 degrees.
09:20Take a deep breath in your pressurized suit, and tackle your first mission.
09:30Put in place a survival and safety plan.
09:35The atmosphere of TRAPPIST-1E might be breathable, but you still keep your helmet on.
09:41You must first test the air to detect harmful toxins or microbes.
09:46TRAPPIST-1E has one thing that Proxima Centauri B does not.
09:56Water.
09:57With an oxygen-rich atmosphere, water, magnificent views, and an eternal sunset,
10:04This planet is a very good candidate for Earth 2.0.
10:08Your team has confirmed it, the air is breathable.
10:13But you don't want to take the risk, not yet.
10:16You didn't come all this way from Earth just to die on this rock.
10:20You will set up your main residence near a water source.
10:24Your team will deploy a water extraction system to filter it.
10:28You will also install a greenhouse and start growing crops to feed yourself.
10:34But the low light is not enough to give your plants the energy they need.
10:39You will therefore install LED lights above your plants.
10:42And yes, kale is still on the menu.
10:46As on Proxima B, you will need a radiation shelter.
10:50This star also spews out violent bursts of radiation.
10:53And you never know when they'll strike.
10:55After your first month on this planet, you are confident.
11:04You'll get through this.
11:05Ultimately, you have no choice.
11:07It's not like you could turn around and travel the 40 light-years back to Earth.
11:12Your camp is growing.
11:14You now have a radiation-proof habitat and a source of nuclear power.
11:19The analyses are reassuring.
11:23The atmosphere is safe, as is the environment.
11:25If the air or soil were toxic, you would surely have noticed it already.
11:30Instead, you discovered that TRAPPIST-1E exhibits conditions similar to Earth's,
11:35with the exception of unpredictable and violent solar flares.
11:39Fortunately, most of them occur on the yellow side.
11:41So, as long as you don't venture too far from the Terminator Zone, it will shoot you fine.
11:48You would conduct many scientific experiments,
11:51chemical composition of air, soil and water,
11:54and would possibly discover extraterrestrial microbial life.
11:59And yes, you may not be the first colonist in this world.
12:03You might even start to take off your helmet.
12:06It's always risky, but TRAPPIST-1E seems safe.
12:10For now.
12:15A century has passed, and the colony is self-sufficient.
12:19and now has several hundred inhabitants.
12:23Over the decades, other ships arrived from Earth.
12:26The new arrivals brought new resources,
12:29more settlers and modernized equipment.
12:32Thanks to all these advances,
12:34TRAPPIST-1E now has several colonies spread across the planet.
12:40Once again, you have managed to survive on an alien world.
12:46But there is still the problem of solar flares and radiation.
12:50Although TRAPPIST-1E is a habitable world,
12:53It's still not perfect.
12:55And there are so many alien worlds in our vast universe.
12:59Don't rush to settle on this one just yet.
13:03The next stop?
13:04K2-18b
13:06K2-18b is one of the most exciting exoplanets ever discovered.
13:16It is located only 120 light-years from Earth
13:18and orbits within the habitable zone of a red dwarf star.
13:22This world is approximately 2.6 times the size of Earth
13:25and is 8.6 times more massive.
13:28Best scenario?
13:29A super Earth covered in oceans.
13:31Worst-case scenario: a mini-Neptune.
13:36It probably has a thick, hydrogen-rich atmosphere.
13:39ideal for trapping heat,
13:41catastrophic for your lungs.
13:43But here's the interesting part.
13:46Scientists have detected the presence of methane.
13:48of carbon dioxide,
13:50and even dimethyl sulfide,
13:52a chemical produced by marine life here on Earth.
13:56Perhaps a clue that we are not alone.
13:59If you were to settle on K218B,
14:02you would not land on solid ground,
14:05because you might find that there aren't any.
14:07And even if there were some,
14:08volcanoes and earthquakes
14:10would make it too unstable.
14:12The solution?
14:13Building a floating habitat.
14:16And no, I'm not talking about a habitat on the water,
14:18but rather a suspended object just above the tops of the clouds.
14:23An extraterrestrial aerial city.
14:26You would need a shield against intense radiation,
14:28robust structures to withstand the elements
14:31and a means of extracting water and nutrients
14:33from the atmosphere or the ocean.
14:36That would be dangerous and you could fail.
14:38But at least,
14:39You would try something new and daring.
14:43Okay, let's now explore another potentially habitable world,
14:46Kepler-186f.
14:55This rock has become part of history.
14:58Kepler-186f was the first Earth-sized exoplanet
15:02never before discovered in orbit within the habitable zone of its star.
15:06When astronomers discovered it in 2014,
15:09It has become a possible Earth 2.0.
15:12That's where the good, beautiful ones begin.
15:15Oh, it's ending too.
15:19Kepler-186f orbits a small, cool red dwarf star
15:23called Kepler-186.
15:26The planet is located just at the outer edge of the habitable zone.
15:30which means it doesn't get much sun.
15:33To be precise,
15:34it receives only about 32% of solar energy
15:37that the Earth receives from the sun.
15:38Without a thick atmosphere to trap the heat,
15:42It's probably a frozen world.
15:45If there is water ice here,
15:47You will need a colossal thermal energy system
15:50to melt it.
15:52And forget about using solar panels,
15:54at least not as a primary energy source.
15:57This red dwarf sun is simply too weak.
16:01You will have to rely on nuclear generators.
16:03like NASA's kilopower fission reactors
16:06to power and heat your base.
16:10There is also a logistical problem.
16:11Kepler-186f is the only planet in the habitable zone of its system.
16:16The other known planets that orbit much closer to the star are burned up.
16:21So, if this place doesn't work,
16:23There is no plan B nearby.
16:25And you are 500 light-years from Earth.
16:28No supplies.
16:29no rescue ship,
16:31No going back.
16:33And if you find that 500 light-years,
16:36That's already a lot.
16:37Well, you might not like it.
16:39where we're going next.
16:411200 light-years from our Earth.
16:49Kepler-62f is a super-Earth exoplanet
16:52in the habitable zone of its star.
16:55This star is called Kepler-62,
16:57an orange dwarf of type K,
16:59which is colder and darker than our Sun.
17:02The planet itself is about 1.4 times the size of Earth
17:06and orbits much further than Earth.
17:09This means it receives less heat and light from Kepler-62.
17:14This would make most of Kepler-62f very, very cold.
17:18especially in the absence of a thick atmosphere.
17:21Large areas of the planet could be permanently frozen.
17:25But if you gave this world the right atmosphere,
17:29That's a completely different story.
17:31If Kepler-62f had an atmosphere at least 3 to 5 times thicker
17:35than that of the Earth,
17:37primarily composed of carbon dioxide,
17:39it could trap enough heat
17:42to make certain parts of the planet temperate and stable.
17:46If you want to establish a colony here,
17:49Your best chance would be to choose the warmest spot on the daytime side.
17:53ideally near the equator.
17:55You will still need a radiation shield,
17:58atmospheric generators and heated shelters.
18:01But it could work.
18:04Kepler-62f is located 1200 light-years from Earth.
18:08So there's no point in hoping to get back.
18:11But if you are willing to do some terraforming, or a lot of it,
18:15This super frozen Earth might just have what it takes to be your future home.
18:19Let's take a short break with the Kepler family.
18:23and let's go to another neighborhood.
18:25Toi-700 is a cold and quiet red dwarf star located only 100 light-years away.
18:36And guess what?
18:37It doesn't constantly explode in a solar flare ready to incinerate you.
18:42A real advantage.
18:44This star is home to four planets.
18:47And the star is Toi-700d.
18:50the only one in the habitable zone.
18:52This planet is approximately 20% larger than Earth.
18:55with a slightly higher gravity than ours.
18:58And it receives about 86% of the sunlight we receive at home.
19:03which seems pretty perfect.
19:05The only downside with the Toi-700d,
19:10This is because this planet is locked by 100-star tides.
19:15So there is a day side and a night side.
19:19But you already know what you have to do.
19:22Exactly, you are heading towards the terminator zone.
19:26Once again, you will still need pressurized shelters,
19:29of a radiation shield and life support system,
19:32while waiting to find out if the atmosphere is breathable.
19:38And while the Toi-700d may appear calm on the surface,
19:42This planet holds a few surprises.
19:46Firstly, we don't know what air is made of.
19:49It could be rich in oxygen,
19:51or it could be a carbon dioxide soup
19:54which would dissolve your lungs.
19:57In that case, keep your helmet on.
19:59And if there is an atmosphere,
20:01Well, fasten your seatbelt.
20:04Equal heat on one side and cold on the other
20:07can create raging weather systems.
20:11Imagine supersonic winds
20:12who are shouting in your camp at all hours.
20:16And then there's the water.
20:18Or not.
20:19So either bring your own,
20:20either extract air from it,
20:22if there is air.
20:23Ultimately, I'm not sure I like the Teoi 700D.
20:31All these extraterrestrial worlds have potential,
20:33and there are many more to explore
20:35where we could potentially settle.
20:37As long as you keep in mind
20:41that you are going to build a civilization
20:43in a place where everyone wants you dead.
20:46A lot of effort just to avoid dying on these worlds.
20:49But we must persevere,
20:51because perishing there is nothing pretty.
20:54But that,
20:55That's a story for someone else.
20:56Is it?
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