- 10 hours ago
How much do you know about the planets of our solar system? By combining information about a planet's seismic activity, density, magnetic field and so on, we can make assumptions about a planet's interior. Let's find out, what's inside them. Why does only Earth have life? What if Earth collided with Mars - which of the planets would survive? The answer's surprising!
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00:00Today, we're going to work our core. So, get ready to sweat.
00:04Oops, sorry. Wrong core.
00:06Hey, we've traveled far and wide, down to the Earth's inner core and up into outer space.
00:12But what if we could combine these adventures and find out what hides in the innards of other planets and
00:18moons in the solar system?
00:20With the help of this interstellar hyperdrill, we can achieve that, at least in heart.
00:26Coordinates are in. All systems ready. And our first destination is…
00:32The Moon. Our Moon, in fact.
00:35We land on its gray and desolate surface under the black sky.
00:39No blue here, because there's very little atmosphere to disperse the light.
00:43The drill starts working, and we first go through the outer layer of the Moon, the crust, just like on
00:49Earth.
00:49We're on the sunny side, so the thickness of this layer is only 43 miles.
00:54But were we to land on the dark side, it would be more than twice as thick.
00:59The Moon is a rocky body, so its crust is largely made of silicon, iron, aluminum, calcium, oxygen, and magnesium,
01:07with much smaller amounts of other elements.
01:10Further down, we find the mantle, and it's a long and tedious journey through.
01:15This layer is about 850 miles thick.
01:17It gets hotter as we go deeper, finding composite minerals, peroxine and olivine.
01:23They're made of iron, silicon, oxygen, and magnesium in different proportions.
01:28Finally, we break through the hard layers and into the semi-molten outer core.
01:33Another journey of about 93 miles ahead through this scalding swamp.
01:37And we dive into the iron ocean of the liquid core shell.
01:41Now, it's nearly 60 miles thick, and the molten metal threatens to evaporate us.
01:46But this drill was made to sustain an extremely heavy onslaught.
01:50And that's how we finally come to a sudden halt.
01:53In the deepest reaches of the Moon, there's a solid iron core, which is 150 miles thick.
01:59We could drill through it, but it would be unnecessary.
02:02So, we just set the flag here and skip to the next planet on our drilling list.
02:08And it's Mercury!
02:09It was hot deep inside the Moon, but on the surface of the smallest planet in the system, it's even
02:15hotter.
02:16That's because it's so close to the Sun, of course.
02:19Alright, let's drill.
02:20Mercury has a pretty thick outer shell, which is both crust and mantle, going about 250 miles deep.
02:27Not the most fascinating journey.
02:29It's not unlike the Earth in many respects.
02:31But then, the drill stops, ramming into a solid metal wall.
02:36It's Mercury's core, which has a diameter of over 2,500 miles.
02:41It takes up to 85% of the planet's overall diameter.
02:45No use trying to drill through this one.
02:47It's fully metal and extremely dense.
02:50Skipping to the next planet.
02:52And we're on Mars now.
02:54Oh, look, it's sunset here.
02:56And the Sun is making the sky hazy blue.
02:59But you know the drill.
03:00I mean, we're here to drill.
03:02So, that's what we do.
03:04Mars' crust is quite thin compared to Earth's.
03:07Just 6 to 30 miles deep.
03:09Its composition is much the same, though.
03:11Iron, aluminum, calcium, potassium, and magnesium.
03:15That's one of the reasons why humans are looking to colonize the red planet one day.
03:19It's very similar to our own.
03:21We're very quick to drill through the first layer.
03:24And the second one, the mantle, is now upon us.
03:27It's a hard and rocky layer about 1,100 miles thick.
03:31Thanks to its size, Mars isn't seismically active any longer.
03:35There's simply no magma boiling close underneath the surface of the planet, making it silent and docile.
03:41It's a long dig, but we finally come to a screeching halt, bumping into the core.
03:46A ball of iron, nickel, and sulfur with a diameter of 2,000 to 2,600 miles.
03:53This core is bigger than that of Mercury.
03:55But the planet itself is larger too, so it figures.
03:58Okay, then, our next stop is even more interesting, because it's Jupiter.
04:04This gas giant has a mass twice that of all the other planets in the solar system combined.
04:10And we landed right in the middle of an ocean.
04:13The ocean, I dare say, it's the largest one in the whole system, and it's made of liquid hydrogen.
04:19The drill goes smoothly through the surface of the planet, because there's no rock or hard metal here,
04:24only gas and liquid.
04:25But the shaking, yikes!
04:28The pressure on this planet is more than just huge.
04:30It's unimaginable.
04:32The drill is barely able to withstand it, and as it's going deeper, the pressure's becoming higher too.
04:38We've reached Jupiter's core, and it's nearly too much to bear.
04:42The temperature here is about 90,000 degrees Fahrenheit.
04:46And the core itself is not solid, but liquid as well, kept together by the immense pressure from all sides.
04:52The drill starts to rattle.
04:53Bad sign.
04:55Let's get out of here before it breaks.
04:57Whew!
04:58No winds, no pressure, no heat.
05:01All around us is a vast, icy wasteland, crisscrossed by ridges and reddish bands.
05:07It's Europa, one of Jupiter's most promising moons.
05:10As we drill through the ice, let me explain.
05:14Europa is one of the candidates to have extraterrestrial life in the solar system.
05:18And it can be found right beneath the icy shell through which we're now digging.
05:23It's only 10 to 15 miles thick, while down below is an enormous saltwater ocean, twice bigger than all of
05:31Earth's oceans combined.
05:32The deepest point on Earth is Challenger Deep, and it's a bit over 6 miles down.
05:37The ocean on Europa, on the other hand, can be up to 100 miles deep.
05:42Who knows what can be lurking in that deep, dark sea?
05:46Anyway, we travel fast through the water and finally reach the bottom of the ocean.
05:51The mantle starts here, and it's made of rock, just like on Earth.
05:55And not much deeper in, we find the metal core of the moon.
05:59Europa is a little smaller than Earth's moon, so it's no surprise we reach its center pretty fast.
06:05Okay, skip drive on.
06:07Let's go further.
06:09Oh, I'd rather we drill in as fast as we can.
06:12Just look around, it's blazing here.
06:14We're definitely on EO, another moon of Jupiter, and the most volcanically active world in the solar system.
06:21Look, that volcano is twice the size of Everest, and it's erupting right now.
06:26Thankfully, we're under EO's surface already.
06:28But that's not to say we're safe.
06:30It's all molten down here too, mostly yellow and brownish hue, due to the huge amounts of sulfur.
06:36The stench must be horrible.
06:39Anyway, the most peculiar feature is that both inside and outside, everything's always on the move on EO.
06:46Jupiter and its other moons create tremendous tidal forces, making the surface of EO swell over 300 feet up and
06:53down.
06:53Like the largest tsunamis on Earth, only here, it's not water, but rock.
06:58The deeper we go, the calmer it gets, though, until we're finally at the iron core.
07:03However, it's still hot here, but at least there's no shaking and swelling like above.
07:08Let's put up another flag and go to the next point.
07:13And that would be Saturn!
07:15The second largest planet of the solar system, and the one best known for its spectacular rings.
07:21Not the only one to have them at all, mind you, but we'll get to it.
07:24Now, as you've surely noticed, our drill is simply falling down through the gaseous hydrogen and helium, making up most
07:32of the planet's surface and atmosphere.
07:34No need to work here.
07:35Just wait and hope the immense pressure won't crush our drill to a hunk of junk.
07:39At last, the pressure's become so enormous that we find ourselves in the liquid hydrogen, and here, we start diving.
07:48Soon, we'll reach the solid core of Saturn.
07:50Ah, here we are.
07:51It's made of iron and nickel, and is actually quite small compared to the rest of the planet.
07:56Well, the last destination awaits, so come on!
08:01And here we come.
08:02Neptune.
08:04The drill immediately deploys anchors, because the winds here are extremely powerful.
08:08They reach speeds five times greater than the most devastating hurricanes on Earth.
08:13Neptune is covered in a pretty thin layer of hydrogen and helium, just like Saturn or Jupiter.
08:19But underneath, there's much more than that.
08:22It's hot, windy, and lonely here on the outskirts of the solar system.
08:26So, let's dig already.
08:27Beneath the gases, there's suddenly a bubbling hot mass of water, methane, and ammonia.
08:34Pew!
08:34These substances are hot, despite Neptune being called an ice giant.
08:38The name comes from its core.
08:41Deep inside, where we're quickly headed right now, a small ball of rock and ice sits all alone.
08:47And despite the boiling temperatures above, the ice beneath is ever cold.
08:57Millions of people around the world go out on the streets and rooftops to look at the amazing cosmic phenomenon.
09:04Another planet, right next to the moon.
09:07A big red one.
09:09At first, everyone's excited.
09:11Mars showing up out of nowhere is having a strange effect on humanity.
09:16Just as the moon can affect the psychological and physical state of some people, Mars' unexpected visit is causing people
09:24to behave pretty strangely.
09:26Every night, the sky is lit up by the white light of the moon and the red glow of Mars.
09:31Many people get a sort of instant insomnia.
09:35Some even stop drinking coffee because they no longer feel sleepy.
09:39Mars brings out energy and a little wildness in people, making them laugh more, and even drives a few poor
09:46people crazy.
09:47They begin to go out of their houses more often and enjoy the unusual night sky.
09:53A few days later, everybody can see what's happening.
09:56Mars is getting bigger.
09:59Scientists announced that the red planet is slowly moving towards Earth.
10:03A collision is inevitable.
10:06Earthlings only have a few years left.
10:08A few months ago, a huge asteroid crashed into the red planet with such force that Mars simply flew out
10:15of its own orbit and went rogue.
10:17The chance that Mars would fly close to Earth was always going to be pretty high.
10:22After about three seconds of being announced, the news went viral and panic set in.
10:28The situation's getting worse and worse.
10:31The closer Mars gets, the more it affects people on a physical level.
10:35Hundreds of videos pop up showing collision simulations of Mars and Earth.
10:40And there's no happy ending.
10:42Want to see what happens?
10:44One famous blogger asked her followers.
10:46The Earth's almost completely covered with water.
10:49And Mars is all dust, sand, and rocks.
10:52Then she puts a huge watermelon in the middle of her room.
10:56From the far end, she launches a bowling ball at it.
10:59Strike!
11:01Mars looks almost the same size as the Moon now.
11:05It's about to come into the Moon's orbit, and it's affecting the Earth's magnetic field.
11:10Floods, hurricanes, tsunamis, powerful thunderstorms.
11:14They go from bad to worse.
11:17Animals go crazy.
11:19Birds no longer migrate south.
11:21The polar northern lights appear in the Caribbean.
11:25The economy isn't handling the news that well.
11:28People stop showing up to work.
11:30Why wouldn't they?
11:31They just want to have fun and be with loved ones.
11:34There are enough resources on the planet to last until the catastrophe,
11:38so no one's even trying to fix the Earth's problems.
11:42Clothing, food, cars, yachts, whatever.
11:45Everything loses its value and becomes free.
11:49Every day, huge street parties pop up all over the world.
11:53People decide to live their last months in peace and harmony.
11:56The global catastrophes uniting humanity like never before.
12:01To go out with a bang, Earthlings team up to organize a huge rock concert.
12:06The Red Giant destroying our beautiful blue planet.
12:10Yeah, rock and roll's the perfect soundtrack.
12:12There's just enough time to eat, dance, party, and listen to good music.
12:18Huge stages are built all over the planet.
12:21It's every musician's last concert.
12:24During all that preparation, hope suddenly appears.
12:27Scientists have calculated all the events that'll occur when Mars crashes into Earth,
12:32and they have a simple plan.
12:34Luckily, humans had already planned on moving to Mars,
12:38so they already have been building spaceships for years.
12:41There's no time to get to another planet before the collision.
12:44But the good news is that people can wait out the disaster just outside Earth's orbit.
12:50You get to sit in a space station, munch some popcorn, relax, and enjoy the show.
12:55When the dust settles, it might just be possible to return to Earth, or what's left of it.
13:01After learning about this plan, people start working on finishing the ship's night and day.
13:06Everyone in the world pitches in.
13:09There are still two years left before the big day.
13:12The huge concert stages are converted into more space stations.
13:16Mars is now giving people more energy, and with epic teamwork,
13:20people manage to create thousands of stations in just a few months.
13:24That's what happens when 7 billion people work together.
13:28Farmers, physical therapists, chefs, engineers, athletes, accountants, all on the same team.
13:35Mars is now closer to us than the Moon.
13:38The red giant blocks out the Sun, and our planet is plunged into darkness.
13:43There are only a few days left.
13:45People are working like ants in a massive colony,
13:48putting the finishing touches on several hundred thousand space stations.
13:52It takes four whole days for everyone to get on board.
13:55Plus, there's the loading of supplies.
13:58Animals, fish, seeds, plants, vegetables, fruits, video games, fruit roll-ups.
14:04The red giant is scheduled to enter Earth's orbit in a couple of days.
14:08That's when it will really pick up speed.
14:11Mars is only a little more than half the size of Earth.
14:14But up in the sky, it looks infinitely huge.
14:18The ships start taking off.
14:21People take a last look around, memorizing every inch.
14:25In a few hours, it'll all change forever.
14:28However, the stations fly up far enough away to clear any orbits.
14:33Two worlds colliding together should still have a soundtrack, though.
14:37Rock stars on every ship organize an outer space music festival.
14:41To the awesome sound of rock,
14:44Mars enters Earth's atmosphere and burns a thin layer of its own surface.
14:49This releases an incredible amount of energy.
14:52It gets faster and faster and smashes into the Pacific Ocean.
14:57A huge blast wave sweeps across the entire planet.
15:01Everything is lit up by flames,
15:03and everyone on the ships has to put on sunglasses to avoid being blinded.
15:08Our blue planet is turning into a fiery one.
15:10The dust of Mars mixes with the water of Earth.
15:14The force of the impact goes through the Earth's crust into the liquid-hot magma.
15:20Hundreds of pieces of Mars, some the size of entire countries,
15:24are somehow floating in the atmosphere.
15:26The collision generates so much energy that all oceans boil and evaporate.
15:32Seas and rivers of molten metal are now spreading all over Earth.
15:37Days, weeks, months pass.
15:39A belt made up of bits of Mars forms around the Earth.
15:43It's like a fiery version of Saturn.
15:46It'll take a long time before it's safe to land back down.
15:49But humanity can't stay alive on the ships all that time.
15:53Food, water, and oxygen will run out after a few years.
15:57But scientists already have a plan.
16:00The ships flip a switch and become huge cryo chambers.
16:04The ships are equipped with energy panels,
16:06and the roasting-hot Earths giving off a lot of energy.
16:10Totally enough to keep the ships working while everyone on board takes a few thousand-year nap.
16:15As soon as the planet cools down, humans will wake up.
16:20Hundreds of thousands of years pass.
16:22One day, alarms go off simultaneously on all the ships.
16:26People wake up, slowly.
16:28Their bodies are exhausted.
16:30But after a few billion cups of coffee, everyone's ready to go.
16:35Down on Earth, new continents should have formed,
16:38and the atmosphere is most likely way different.
16:40The planet might have lost its original orbit,
16:43so it might be spinning at a different angle.
16:46The seasons as we know them, gone.
16:48All the water on Earth evaporated in the first few hours.
16:52But there were huge glaciers on Mars, which might have melted on impact.
16:56Mars may have shared its water with our planet.
17:00The clouds of dust and dirt should have settled by now.
17:03And the ground should be pretty good for growing stuff on.
17:06All that magma probably spewed up a bunch of useful minerals and chemicals.
17:11It's going to be difficult, but humanity somehow must adapt to the new Earth.
17:16People are ready for anything.
17:18All the Earthlings run to the nearest windows
17:21to see what their beloved planet looks like after all these centuries.
17:25Um, where is it?
17:27People are craning their necks, looking out at the empty spot where the Earth used to be.
17:33The impact of Mars was so strong that it pushed the Earth out of its orbit around the Sun.
17:39It's gone.
17:40Great.
17:41What are we going to do now?
17:43Some bearded guy grabs a guitar and says,
17:46Let's play!
17:49The planet races through space.
17:52Its orbit is unstable, like a pool ball gliding across the table, looking for a target to collide into.
17:58Only this ball is the size of Mars, and it's going 9,000 miles per hour.
18:04Boom!
18:05It crashes into another planet.
18:08This Mars-sized object was called Theia, and what it smashed into was Earth.
18:14The impact released 100 million times more energy than the asteroid that wiped out the dinosaurs.
18:21The planetary collision threw tons of solid material from both objects out into space.
18:27But only one of the bodies survived.
18:30Theia was obliterated and then swallowed entirely by early Earth.
18:34But that debris didn't go flying endlessly into the cosmic void.
18:39No, something crucial happened.
18:41All those solid chunks gathered into a cloud.
18:45Gravity squished it together, pressing more and more.
18:49And in the end, our Moon was born.
18:52So goes the theory.
18:54At the time of the impact, the solar system was just forming.
18:58And this rendezvous of epic proportions probably wouldn't have happened if it weren't for a newly formed Jupiter,
19:05throwing Theia off its orbit and straight into Earth.
19:09Our young planet withstood the blow.
19:12Time passed.
19:13Earth evolved.
19:14Its surface will become unrecognizable over the next 4.5 billion years.
19:20It's hard for the human mind to understand this vast amount of time.
19:25So, we'll squeeze it all into one day.
19:28If midnight is when Earth first formed from gas and dust that remained after the Sun's creation,
19:34the next 4 hours show a lifeless planet.
19:38Red hot, covered in lava, constantly bombarded by asteroids and, as you know by now, even a whole other planet.
19:47Yet life finds a way.
19:49The first cells appear.
19:51It's 4 a.m. on the clock.
19:53At 2.08 p.m., we see the first single-celled organisms form.
19:58It's not until 8.28 p.m. that sea plants appear.
20:0220 minutes later, what's this?
20:05Jellyfish.
20:06After them, the planet flourishes with different fish, reptiles, insects.
20:11The forests grow at 10.30 p.m.
20:14Between 10.56 and 11.40, dinosaurs roamed the Earth.
20:19The giant lizards ruled our planet for less than one hour.
20:23A minute before the dinosaurs' extinction at 11.39 p.m., the first mammals begin to run around the planet.
20:30At 11.58 and 43 seconds, humans appear.
20:35In the cosmic scale of things, we've only ruled this planet for 1 minute and 17 seconds.
20:42So here's the main question baffling scientists.
20:45Why didn't life on Earth ever stop?
20:48It had every chance to cease.
20:50Why didn't our planet become like Venus or Mars?
20:54They both once had an atmosphere and oceans.
20:57Today, they're lifeless deserts.
20:59Forget about complex scientific concepts and theories of the universe's structure.
21:05Our little rock and all its inhabitants are just incredibly lucky.
21:10Professor Toby Tyrell at the University of Southampton used computer programs and climate simulations
21:17to solve the puzzle of why asteroid collisions in ice ages didn't turn our little rock into a lifeless wasteland.
21:25The research team took not 10, 100, or 1,000 virtual planets similar to Earth.
21:31They used 100,000 for the experiment.
21:34And every single one of those 100,000 were simulated 100 times.
21:40They exposed these virtual planets to different phenomena.
21:44They were bombarded by asteroids, frozen, exposed to epic eruptions of supervolcanoes
21:50that blackened the skies and blocked the surface from the sun's rays.
21:54Just 9%, or 8,700 of them, were successful one time in 100 simulations.
22:01Of that group, 4,500 planets remain inhabited 10 times.
22:06Only on one planet out of 100,000, life didn't stop all 100 times.
22:13If life is a lottery, Earth got extremely lucky.
22:17In 2009, the unique Kepler telescope was launched into space.
22:22Its task?
22:23Search one patch of the night sky, or 150,000 stars, for rocky Earth-like planets.
22:31Over 9 years in service, it ended up surveying more than 500,000 stars.
22:37In all that time, with all those observations, over nearly a decade,
22:43Kepler discovered 2,600 possible Earth-like planets.
22:47The weird thing is, most of them are a type you can't find in our own solar system.
22:52There's something between the size of Earth and Neptune.
22:55But back to the real Earth.
22:57If you go far from the city and look up at the sky, you'll see an ocean of stars.
23:03If you're lucky, and it's a clear night, with an unaided eye, you could count a maximum of 2,500
23:10points of light.
23:12Yet, there are at least 100 billion stars in the Milky Way.
23:16Some estimates put the numbers of stars in the Milky Way up to 400 billion.
23:22So, where's this giant range coming from?
23:24Well, counting stars isn't exactly an easy job.
23:28Scientists obviously don't number each one individually.
23:321, 2, 3, and so on.
23:34You know how long it takes to count just 1 billion?
23:37Over 100 years!
23:38Now, multiply that by 400.
23:42Instead, they look at small patches of space and use some complex scientific formulas to make educated guesses of how
23:50many stars there are in total.
23:52You can do a similar experiment yourself.
23:54Imagine a bucket filled with 10 pounds of rock, sand, soil, and other items.
24:00Your job?
24:01Understand how many rocks are in that mix.
24:05We'll count only those rocks that are visible to us from above.
24:09Get a rough estimate of their volume and weight, what percentage of the total we can see, and, with some
24:15calculation, you can get a number.
24:17Is it exact?
24:18Nah.
24:19Why?
24:20Because you can't know if the rocks in the bucket are spread evenly throughout.
24:24Or if they're all about the same size throughout.
24:27What if the ones at the bottom, if there are any, are bigger or smaller than your sample view?
24:33They could have completely different weights and volumes.
24:36That bucket is our Milky Way galaxy, and the rocks you are counting are stars.
24:42The point?
24:43Scientists can't know for sure how many stars there really are.
24:47Maybe 100 billion?
24:49Or perhaps 4 times that.
24:51Of those, 4 billion are like our sun.
24:54With our own galaxy, the most accepted estimate for planets that could potentially support life is 300 million.
25:01Though, as the tradition of scientific inexactness goes, that number could be up to 5 billion or more.
25:08Either way, lots of real estate to choose from.
25:12And that's just the Milky Way.
25:14But get this.
25:15It's just one of 200 billion galaxies in the observable universe.
25:20The most recent research puts that number 10 times higher.
25:24Something like trillions of galaxies in space.
25:27And we've only studied less than 10% of them.
25:31As for how many stars there are in the universe, scientists put it at 1 septillion.
25:37That's 1 followed by 24 zeros.
25:39Again, it's all estimates, because we can't know for sure.
25:44So far, one thing is clear.
25:46Our Earth is the only place in the universe that we know of where there's life.
25:51And this planet has done everything it can to change that.
25:55Over the past 540 million years, more than 20 major extinction events have occurred.
26:02The last one was 66 million years ago.
26:05Yep, it was the one that took out the dinosaurs.
26:08And 75% of all life on this planet, for that matter.
26:12An object 7 miles across in diameter smashed into our planet.
26:17It was going 120 times faster than the fastest car today.
26:21Over 900,000 miles all around the impact site, everything caught fire.
26:27A huge tsunami swept across the world's oceans.
26:31Billions of tons of dust and sulfur rose into the sky and blocked the sun's warm rays.
26:37A global cooling came to Earth.
26:39A little over 200 million years ago, there was a lesser-known extinction event that wiped out half of all
26:46life on the planet.
26:48Most likely, volcanoes or an asteroid strike are to blame.
26:52Other theories say the movement of tectonic plates triggered another ice age.
26:57At that time, huge crocodiles ruled the Earth.
27:00They disappeared, and new animals entered the arena of history.
27:04Dinosaurs.
27:05But the worst this planet has ever seen was the Permian-Triassic event about 250 million years ago.
27:1380% of marine life, 70% of land animals and plants.
27:18All gone.
27:20Volcanoes spewed out a colossal amount of lava, where modern-day Siberia is.
27:25But it affected the entire planet.
27:28Around 445 million years ago, the dominant life form on our planet was marine invertebrates.
27:35There was only one continent, Gondwana, and plants were just starting to flourish on land.
27:41But something happened that took out 75 to 85% of all living organisms.
27:47It could have been an ice age, rising temperatures, or a more daring theory.
27:52Some think it could have been a huge star exploding 6,000 light-years from Earth.
27:58It launched a jet-like gamma ray burst that ripped across space, and poor little Earth happened to be in
28:05its path.
28:06It burned off the ozone layer instantly.
28:09Yeah, we kind of need that thing to protect us.