These Facts About Space Will Rocket Your Mind
Get ready to blast off into the cosmos with some mind-blowing facts that'll make your brain feel like it's soaring through the galaxy! From black holes that gobble up entire stars to planets made of diamond and stars that rain glass, this video is packed with jaw-dropping tidbits that'll have you seeing stars in a whole new light. Trust me, you won't want to miss this stellar adventure! ✨
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00:00 Uh-oh, something is nearing the surface of the planet.
00:05 It looks like a fireball, hurtling closer and closer at a truly incredible speed.
00:10 Soon, it becomes obvious that the collision is inevitable.
00:15 The impact leaves a huge crater, it evaporates thousands of cubic miles of solid rock, and
00:20 it also sets off a series of terrible natural disasters.
00:24 I know what you're thinking.
00:26 You believe I'm talking about the catastrophic collision that occurred around 66 million
00:31 years ago on Earth.
00:32 You know, the one that's responsible for the extinction of non-avian dinosaurs and
00:37 three-quarters of other life forms on our planet?
00:40 But no, the disaster I'm talking about happened on a different planet.
00:45 Scientists think that our close neighbor, Mars, once experienced the same catastrophe
00:49 that struck Earth.
00:51 It happened around 3.4 billion years ago.
00:54 An asteroid collision might've caused a mega-tsunami on the Red Planet, similar to
00:59 the one that caused the Chicxulub impact on Earth.
01:03 Scientists have identified an impact crater on Mars that was probably left by a comet
01:08 or asteroid collision with the surface of the planet.
01:11 Most likely, the space body landed in an ocean in the Martian northern lowlands.
01:16 And the impact was so powerful that it caused a mega-tsunami.
01:22 For the latest studies, the exact location of the impact crater wasn't verified.
01:27 It was just a theory.
01:28 To confirm it, a team of astronomers simulated a comet and asteroid collision in the area
01:34 where they supposed the impact crater was.
01:37 They even named this crater "Paul."
01:39 Paul is 68 miles across and lies in a region that is almost 400 feet below the supposed
01:46 sea level.
01:47 Anyway, the simulations formed several craters of the same size as Paul.
01:52 One of the simulations claimed that these craters had been left by a 5-mile-wide asteroid
01:58 that had encountered strong ground resistance.
02:01 The other simulation showed that the craters had been caused by a bit smaller asteroid
02:05 that met a weaker ground resistance.
02:08 But according to both simulations, the impact crater was almost 70 miles in diameter, and
02:14 the collisions produced mega-tsunamis up to 900 miles away from the center of the impact
02:19 site.
02:20 These simulations also helped scientists estimate the height of the tsunami.
02:24 It was about 820 feet tall, almost as tall as the Eiffel Tower.
02:29 The authors of the study also suggest that the Paul crater might be similar to the Chicxulub
02:35 impact crater on our planet.
02:39 The Chicxulub asteroid, as we now know it, is believed to come from the outer reaches
02:44 of the Solar System.
02:45 This space body was at least 6 miles across.
02:48 It crashed into the shallow seawaters near the Yucatan Peninsula.
02:53 This splashdown was so powerful that it left its signature on the entire face of the planet.
03:00 In 2021, researchers found out that the collision had carved mega-ripples into Earth's crust
03:06 in the region of modern-day central Louisiana.
03:09 An even newer study suggests that the asteroid also triggered a tsunami so devastating it
03:15 eroded seafloor sediments half a world away.
03:19 The team of scientists remodeled the events of the first 10 minutes after the impact,
03:24 and the models showed that the asteroid had produced waves up to 30,000 times greater
03:29 than one of the largest tsunamis people have ever recorded – the Indian Ocean tsunami
03:34 that hit Indonesia in 2004.
03:37 The collision displaced so much water that it created a wave almost a mile high.
03:42 That's like two Burj Khalifas, which is the tallest construction in the world, stacked
03:47 one on top of the other.
03:49 And of course, all that empty space didn't stay empty for long.
03:52 The ocean gushed back to fill the crater, but in the process, it only ricocheted off
03:58 the crater's rim, which produced even more waves.
04:02 After that, tsunami waves that were more than 33 feet tall traveled around the world at
04:07 a speed of 3 feet per second, lashing at all coastlines on their way.
04:12 Imagine a 3-story building rushing up to you.
04:15 No wonder the largest and fastest-moving waves occurred near the impact area in the open
04:20 waters of the Gulf of Mexico.
04:22 Those rose more than 330 feet tall, which is taller than the Statue of Liberty, and
04:27 moved at a speed 10 times greater than more distant tsunami waves.
04:34 But back to the Red Planet.
04:36 Some experts think that not one but two mega-tsunamis could happen on Mars.
04:41 They could be triggered by a pair of meteor impacts that were several millions of years
04:45 apart.
04:47 Between these two collisions, Mars went through a period of climate changes.
04:51 As a result, liquid water on its surface turned into ice.
04:55 In other words, the first asteroid impact most likely produced waves composed of liquid
05:00 water, and the second tsunami was probably formed by rounded chunks of ice water.
05:06 By the way, the largest asteroid to have ever crashed into Earth might not actually be the
05:11 one that ended dinosaurs.
05:14 A much more catastrophic collision likely happened about 3.5 billion years ago.
05:20 New evidence scientists found in northwestern Australia suggests that the asteroid I'm
05:25 talking about was 12 to 18 miles across.
05:29 It struck Earth at an immense speed, releasing an unimaginable amount of energy.
05:34 Now this made me think, what if something like that happened these days?
05:38 More than 30,000 objects that are circling Earth these days could potentially crash into
05:43 our planet.
05:44 NASA considers around 1,500 of them to be potentially hazardous.
05:49 These space rocks are the remains left after the Solar System was formed some 4.6 billion
05:54 years ago.
05:56 For example, in 2004, astronomers discovered a huge asteroid nearing Earth.
06:02 The first observations showed that the chance of the space rock hitting our planet was less
06:07 than 3%.
06:09 The asteroid was named Apophis.
06:10 It's more than 1,200 feet across and weighs about 20 million tons.
06:15 It's supposed to streak across the sky on April 13, 2029.
06:20 Apophis will pass at a distance of 19,000 miles away from Earth's surface.
06:25 But even though the space rock might miss our planet in 2029, it doesn't mean it won't
06:30 return 15 years later in 2036.
06:35 If such an object hits our planet, the consequences will be unpredictable.
06:40 They can vary from shattered glass and broken windows to most life forms getting wiped off
06:45 the face of the Earth.
06:46 And it'll probably affect the Internet.
06:49 That last thought is truly scary.
06:52 But luckily, modern technologies are likely to help us avoid any catastrophic consequences.
06:58 Experts have developed several ways to prevent a real-life disaster movie from happening.
07:02 For one thing, we could use a spacecraft to knock this visitor from outer space off its
07:08 course.
07:09 Or it could somehow be blasted into pieces.
07:12 Scientists could also slow the thing down with the help of concentrated sunlight.
07:17 Or people could tug it away with a gravity tractor.
07:20 That's a theoretical spacecraft that can influence objects in space without touching
07:25 them.
07:26 In sci-fi movies, a huge asteroid often sneaks up on Earth and turns out to be a nasty surprise
07:32 to astronomers.
07:33 It hurdles toward our planet at breakneck speed and gets discovered just weeks or even
07:38 days before the collision.
07:40 Our Sun.
07:42 Scenario 1.
07:44 Something strange just happened now.
07:46 Every TV channel.
07:47 The news.
07:48 They're all talking about a black hole that came closer to us.
07:52 On the spot where our Sun used to be.
07:55 You can even see an accretion disk.
07:57 And the background of the sky looks kind of distorted.
08:00 Which means it got really close.
08:02 Normally, black holes are so far away that we can't see them with the unaided eye.
08:07 You can't even see them with a telescope directly.
08:10 What's it doing here so close?
08:13 And where's the Sun?
08:14 Did the black hole swallow it?
08:16 The Sun used to be in the center of our solar system.
08:19 Far enough not to burn us, but still close enough to give us light, warmth, and beautiful
08:24 scenes when it rises in the east and goes to rest in the west.
08:28 Hey, this one even rhymes.
08:31 It gave us life.
08:32 The most massive body in our solar system contains 99.8% of its total mass.
08:38 It's so wide, you could fit more than a million Earths inside of the Sun.
08:43 Maybe our Sun turned into a black hole.
08:45 But it's way too early for that to happen.
08:48 I mean, that's how they form.
08:50 When enormous stars come to the end of their life cycle and explode, which is called a
08:54 supernova, they end up collapsing on themselves, becoming very small.
08:59 It's a tiny size and a huge mass.
09:01 That's what makes black holes' gravity so strong.
09:04 And even light that comes too close can't escape.
09:08 And all the stars in the universe are shrinking and will disappear at some moment.
09:13 Our Sun loses 4 million tons of mass every second.
09:16 And eventually, the only energy left in the universe will be generated by black holes.
09:22 A black hole is surrounded by dust, gas, and radiation.
09:26 The radiation is very dangerous, so we hope our planet won't come near it.
09:31 Our solar system doesn't have light anymore.
09:33 No light and no heat either.
09:36 So even Mercury and Venus will probably get covered in ice pretty soon, not to mention
09:40 Earth.
09:41 Do I need to say nothing will survive this new ice age?
09:45 The only salvation might come from the accretion disk that spins so fast it generates heat.
09:51 But that's too many chances to take.
09:53 Still, at least if the black hole has the same exact mass as the Sun before it, all
09:58 the planets will remain in the same orbits, Earth included.
10:01 But if it has a mass bigger than our Sun, which is something our scientists are currently
10:06 trying to figure out, then bye-bye, solar system.
10:09 It was nice knowing you.
10:11 Scenario 2.
10:13 Oh no, what's happening?
10:16 It was supposed to be a nice sunny day, but now you see darkness descending so abruptly.
10:21 How come it's night, yet the clock says it's 2pm?
10:24 And the Moon looks different.
10:28 The TV reports say our Sun is gone.
10:31 And due to some mysterious events, the Moon is not orbiting the Earth anymore.
10:36 It's in the center of our solar system now.
10:38 We don't have much time left.
10:40 Since the Sun is not in the center of our solar system, we now have 8 minutes and 20
10:44 seconds to become aware of it.
10:46 It may take millions of years for the Sun's energy to travel from its core to the surface,
10:51 but 8 minutes and 20 seconds is exactly how long it takes for sunlight to reach Earth.
10:55 The light takes a journey across 93 million miles, which is the distance that separates
11:00 us from the Sun.
11:03 We are not in the habitable zone anymore.
11:05 The habitable zone is the distance from a star.
11:07 In our case, the Sun, at which liquid water could exist on the surface of a planet.
11:12 Now that the Sun's gone, its light won't reach us anymore, and our planet will gradually
11:17 become a frozen, lifeless rock.
11:20 Who knows if we'll have enough time to come up with some technologies that would provide
11:23 us with the solar energy we need to sustain life on Earth.
11:27 If not, well, millions or billions of years later, scientists from some other civilizations
11:33 would explore it, trying to find evidence if life ever even existed there.
11:37 It would be the same as we do with Mars and other planets in our solar system, trying
11:41 to figure out if they've always been lifeless or if there might be a sign that some organisms
11:46 used to live there.
11:48 Something else, also vital for our life, travels at the speed of light.
11:52 Gravity.
11:53 Without the Sun, for roughly 8 more minutes, the planets would continue circling the empty
11:58 center of our solar system, until the clock ticks and they finally drift somewhere into
12:03 an unknown direction of outer space.
12:06 Our Moon doesn't have a strong enough gravity to keep us in place.
12:09 It can't shine so brightly to give us warmth and support life.
12:13 It's so far, we can barely see it now.
12:16 Without the Moon, that peacefully travels close to our planet as it used to, we can
12:20 see tides are getting lower incredibly fast.
12:23 Oh, and it's becoming really windy.
12:26 Tides are so much stronger and faster now.
12:29 When things were normal, our planet sat at a 23.5 degree tilt, which is the reason we
12:35 had changing weather and seasons.
12:37 Now the tilt is so extreme, it's getting very cold very fast.
12:42 And our time is almost up.
12:44 People are screaming, everyone's in panic.
12:46 We still have maybe one minute left until we sink into eternal darkness.
12:52 Scenario #3.
12:53 We're not sure what exactly happened and how the life we carelessly lived yesterday
12:57 came to an end.
12:59 No one could predict it, but it seems that out of nowhere, a giant neutron star took
13:04 the spot where our Sun used to be.
13:06 It's not something we'd recognize on our own.
13:08 We just noticed something was different, and the Sun kinda got smaller and weirder.
13:13 The rest we heard on the news, and no one knows how it happened.
13:17 Maybe our Sun is somewhere behind the neutron star.
13:20 Or the star pushed it out of our solar system and into an unknown direction?
13:25 A neutron star is the densest space object we know about.
13:29 It has almost twice as much mass as our Sun.
13:31 But it's all squeezed into a star only 10 miles, 15 kilometers, across, which is about
13:37 the size of a city on Earth.
13:39 A neutron star forms when a huge star runs out of fuel.
13:43 It collapses in a big explosion.
13:45 This very central region, the core, collapses, which is why every electron, negatively charged
13:51 particle, and proton, positively charged particle, crush together into a neutron, which is either
13:57 uncharged or neutrally charged.
14:00 We're in a very tricky situation now, basically waiting for our end to come.
14:05 This neutron star has gravity 2 billion times stronger than the one Earth has.
14:10 This means our new "Sun" will pull all the planets in our solar system towards itself
14:15 and eventually destroy them.
14:18 Now as a child, weren't you taught not to play with your food?
14:21 Well, apparently, these astronauts weren't.
14:25 Floating Jello cubes across the cabin while in zero-g is a lot of fun, but it is also
14:30 a sign of a potential problem called space euphoria.
14:34 No one ever considered that extreme happiness in space could become a severe problem, but
14:39 it can become a serious problem, and that's no kidding.
14:43 For many years, space euphoria went undetected, although it was right there, front and center,
14:48 for all to see.
14:50 When Apollo 14 astronaut Alan Shepard smuggled golf balls onto the Moon and tried to create
14:56 a tiny "moon" for the Moon by attempting to hit a golf ball into orbit around the Moon,
15:01 everyone thought it was funny.
15:03 Apollo 16 astronaut Charles Duke thought it would be funny if he tried to compete with
15:07 the 1972 Olympic athletes back on Earth.
15:11 He attempted to outjump the Olympic athletes to benefit from the 1/6th gravity on the Moon.
15:16 Duke jumped so high that he rotated onto his back and fell crashing onto the life support
15:21 system in his backpack.
15:23 It could've been a fatal fall if the bag had cracked.
15:26 Duke's commander John Young said, "That's not funny."
15:29 And it sure wasn't.
15:31 Yet when Apollo 17 astronauts began dancing and singing children's nursery songs while
15:36 collecting rock samples, everyone still thought it was cute.
15:40 Space euphoria again went unnoticed.
15:43 As early as 1965, when Ed White became the first American to walk in space on a tethered
15:49 spacewalk, his space euphoria became evident.
15:53 He stayed out much longer than was necessary to test his mobility with the very first jetpack,
15:58 or MMU as it was called, officially the Manned Maneuvering Unit.
16:02 In his own words, "I'm not coming back.
16:05 This is fun!"
16:06 Finally, when ordered to return to his Gemini spacecraft, Ed White said it was "the saddest
16:12 day of my life."
16:13 Obviously, something sinister is at work with space euphoria.
16:18 Weightlessness, combined with the view of Earth passing below, creates an exhilaration
16:22 that overcomes all sense of duty.
16:25 It is the great danger of space euphoria.
16:28 Now in hindsight, the effects of space euphoria could be seen when Apollo 17 astronauts drove
16:34 the Lunar Rover on the Moon.
16:36 They exceeded the recommended speed limit and could be heard whooping and yelling as
16:40 the rover rocked onto two wheels, even becoming airborne at times.
16:45 Canadian astronaut Chris Hadfield was busy at work during his tethered EVA (extravehicular
16:50 activity) when he paused to look over his shoulder.
16:53 The glory of space smacked him in the face.
16:56 He was so emotionally overwhelmed at the magnificent beauty of the Milky Way galaxy that tears
17:02 began to fill up Hadfield's eyes.
17:04 Now in space, tears do not flow down your cheeks; they pool up in your eyes.
17:09 Hadfield had become blinded by tears of joy.
17:12 But Hadfield, against protocol, refused to tell his supervisors on Earth.
17:17 Only after he was no longer able to work did Hadfield speak a famous quote, "Houston,
17:22 I have a problem."
17:24 It was a direct result of space euphoria.
17:27 Astronaut Hadfield managed to get back into the space shuttle, but his EVA was not fulfilled.
17:32 Space euphoria had interfered.
17:35 There is another aspect of space euphoria that deserves serious attention.
17:39 It is something called the "overview effect."
17:43 Weightlessness in space affects everything from the physical and psychological health
17:47 of the astronauts to the physics of using all the mechanical equipment of the spacecraft.
17:52 However, weightlessness in space is not due to a lack of gravity.
17:57 Astronauts orbit Earth less than 300 miles up, called LEO, low Earth orbit.
18:01 There's plenty of gravity in low Earth orbit, the Earth's gravity keeps the Moon in orbit,
18:06 and the Moon is about 250,000 miles away.
18:10 In fact, a 150-pound astronaut would weigh 142 pounds in LEO.
18:16 Weightlessness in space is due to free fall, not lack of gravity.
18:20 Earth goes up, must come down.
18:23 The rocket blasts off, and about 8 minutes later, the engines shut off.
18:27 The spacecraft begins to fall back to Earth.
18:30 Fortunately, by this time, the rocket has achieved orbital velocity, which is about
18:35 17,500 miles per hour.
18:37 So that it falls towards Earth, but never hits the Earth.
18:41 It keeps falling and falling around and around, precisely in the same curved path as the surface
18:46 of the Earth.
18:47 It's in orbit.
18:49 It is free fall, even though everyone calls it zero-g, it's not.
18:54 If you were to place a bathroom scale under your feet when in free fall, it would show
18:58 zero.
18:59 You would weigh nothing.
19:00 That's because the bathroom scale is falling too.
19:04 The exciting thing is that astronauts retain all their muscle power, their mass stays the
19:08 same.
19:09 Therefore, they can lift heavy equipment in space that would weigh hundreds or even thousands
19:14 of pounds on Earth.
19:16 Astronauts become superhumans in space.
19:18 And that creates another unusual situation.
19:21 There are lots of unusual situations in space.
19:25 On the very first trip to the Moon, the Apollo 8 astronauts were not even scheduled to look
19:30 back and photograph the Earth.
19:32 Apollo 8 astronauts took only a limited number of pictures of Earth.
19:35 That's unusual and kinda weird.
19:38 But Earthrise from the Moon became perhaps the most influential environmentalist picture
19:43 of the 20th century, and it wasn't even planned.
19:47 But this is the key to understanding the overview effect.
19:51 Surprise at the unexpected.
19:53 Even today, almost all globes of Earth are not of Earth.
19:57 Globes in schools and libraries show each country, usually in different colors.
20:01 Each country, sure enough, contains a star, but it is to mark the capital city of that
20:06 country.
20:07 It is not how the Earth looks from space.
20:09 These globes are not globes of the planet Earth.
20:12 In fact, it isn't easy to even find a globe of the planet Earth.
20:17 Read the labels on these classroom globes.
20:19 The geopolitical world.
20:21 These are globes of a place called "the world."
20:24 There is no planet called "the world."
20:26 The world does not live in space.
20:28 It lives on someone's desk or shelf.
20:31 The definition of space is geological in origin.
20:35 Space is defined as existing up to, but not including, the atmosphere of Earth.
20:40 Earth isn't even an astronomical object.
20:43 It explains why the very first mission to the Moon, the Apollo 8 mission, had not scheduled
20:47 any pictures of Earth.
20:49 Selfies weren't invented then.
20:51 It also explains why the psychological impact of seeing Earth rise from the Moon was so
20:56 profound.
20:57 Now, did you know that there's an astronomical object in which space and time actually swap
21:03 places?
21:04 How does that work?
21:06 And what exactly does swapping space and time mean?
21:08 Well, let's figure it out.
21:11 Imagine that you're on a spacecraft.
21:13 The vehicle can only move straight.
21:15 Your path leads to some inevitable point, and you have no idea what lies ahead.
21:20 You can only hope that it won't be too bad.
21:23 Meanwhile, everything around you is complete madness.
21:27 A chaotic collage of many historical events.
21:30 What do you see?
21:31 Ancient humans and dinosaurs?
21:33 The birth of the Universe?
21:34 A future?
21:35 Who knows?
21:36 That's what the Universe would look like if we swapped time and space.
21:42 And theoretically, this is what you would see if you fell into a black hole and somehow
21:47 were able to survive.
21:48 But how is something like this even possible?
21:52 First of all, let's discuss time and space.
21:55 Imagine drawing a light bulb on a sheet of paper.
21:58 Then grab one more sheet and draw how it lit up.
22:01 Right now it's just a small circle of light.
22:04 On your sheet, the circle of light is growing.
22:07 It gets bigger and bigger in size, until finally it turns into a giant circle.
22:13 In real life, the bulb lights up in the blink of an eye.
22:16 That's because the speed of light is the fastest in the Universe.
22:20 But here, on our drawings, we captured the propagation of light frame by frame.
22:25 We see how over time the light has grown from a small dot to a large circle.
22:30 But if you connect these circles, doesn't it remind you of some shape?
22:35 For example, a cone?
22:37 Yes, exactly.
22:38 This is called a light cone.
22:40 And time is the central axis of this cone.
22:44 Why?
22:45 Because light turns from a small dot into a large circle over time.
22:49 To remember it, let's draw a time vector -- an arrow inside the cone.
22:54 It goes from the past to the future.
22:56 Meanwhile, the circles are space.
22:59 In space, we can move however we want, in any direction.
23:03 We can move up or down, in zigzags and so on.
23:06 But no matter what zigzags we draw, along the timeline, we're always moving forward.
23:12 We can't turn back in time, and we can't stop it.
23:15 This helps us define time and space.
23:19 Time is the direction in which the light cone is oriented.
23:22 This is the direction where all our paths lead, and where our future inevitably lies.
23:27 And space is the whole variety of directions perpendicular to the timeline.
23:32 This is a straightforward graph.
23:35 If it could be applied to the entire universe, then time would flow the same everywhere.
23:40 However, if you've watched at least some popular sci-fi movies, you know that this isn't the
23:45 case.
23:46 In reality, time can be crazy.
23:49 For example, if you're chilling near a black hole, what will be two hours for you may turn
23:54 out to be 20 years for your friend on Earth.
23:57 But why?
23:58 Well, take a deep breath.
24:00 Now gravity comes into play.
24:02 Oh, I know about gravity.
24:04 It's that thing that helps me to stand on the ground, you may think.
24:07 But it's much, much more complicated than that.
24:11 Gravity is one of the basic physical forces in our world, and it's incredibly powerful.
24:16 In fact, she's such a girl boss that she can distort space and time.
24:21 She can literally influence the speed of time like an almighty wizard.
24:25 How?
24:26 Well, let's take something slightly bigger than a light bulb.
24:29 For example, a supernova.
24:32 Somewhere in the universe, a star has just made a boom.
24:35 How do we know about it?
24:37 Well, nothing in the universe -- no sound, no radio waves, nothing -- travels faster
24:43 than light.
24:44 So, we'll know about the birth of a supernova only when we see it.
24:48 And this will happen only when its light cone grows enough and reaches our planet.
24:52 So, the light cone grows and grows.
24:56 So far, everything is fine.
24:57 And finally, it reaches our planet.
25:00 But there's a catch.
25:01 You see, our planet is very massive.
25:04 VERY massive.
25:05 And it has pretty strong gravity.
25:07 What happens then?
25:09 Gravity changes the direction of the light cone.
25:12 It begins to attract the cone to the center of our planet.
25:15 And with it, it also attracts our arrow of time.
25:19 That means it slows the time down.
25:21 And the closer the light cone is to us, the more the arrow bends, and the slower time
25:26 goes.
25:27 What does it mean?
25:28 Well, for example, the fact that the watch on your ankle will lag behind the watch on
25:33 your wrist.
25:34 That your head is aging faster than your legs.
25:37 And that astronauts in Earth's orbit age a little slower than people on Earth.
25:42 This is what scientists call "general relativity."
25:45 Right.
25:46 But how does this relate to our topic?
25:48 How can we understand what will happen if we swap space and time?
25:52 Don't worry, we're almost there.
25:55 Now imagine a cosmic body with incredibly strong gravity.
25:59 It bends time and space so much that it feels like they swap.
26:04 This is a black hole.
26:06 A black hole attracts absolutely everything to its center.
26:09 No stars, planets, no light can escape from there.
26:13 Let's say our light cone is approaching it.
26:16 First, as usual, time begins to bend toward the center of the black hole, attracted by
26:21 its gravity.
26:22 But the gravity is very strong, so it bends more and more.
26:26 And time goes slower and slower the closer you're to the center.
26:30 In the end, the light cone crosses the boundary of the black hole, the so-called "event
26:36 horizon."
26:37 At this point, it gets so distorted that now it's literally pointing downwards.
26:42 We can say that time has changed its direction.
26:45 Time is pointing downwards.
26:47 What kind of nonsense is that, you may ask?
26:49 It'll be easier to explain in a real example.
26:53 Imagine you're a crazy astronaut who decided to jump into a black hole.
26:57 And there's an observer in the spaceship who watches you doing this for some reason.
27:02 At first, for you, nothing changes.
27:04 You look at your watch, you see that 5 minutes have passed, and everything's okay.
27:09 But for the observer?
27:11 First of all, you'll fall for a very long time.
27:14 The observer has been sitting there for 50 years, and you're still falling.
27:19 All because your time has slowed down.
27:22 Secondly, since space is also distorted near the black hole, the observer will see how
27:27 you'll begin to stretch like spaghetti.
27:30 This is a scientific term, by the way.
27:32 It's called "spaghettification."
27:36 They say, somewhere out there, there's a pen that can work in zero gravity, at extreme
27:40 temperatures, and even underwater.
27:43 They say this pen can write on almost any surface.
27:46 Or if you turn it upside down, or when your surroundings are heated up to 570°F. They
27:52 say NASA spent millions, or probably billions of dollars, and almost a decade to develop
27:58 such a pen.
27:59 The problem with ballpoint pens in space is that they don't work in the conditions of
28:03 weightlessness.
28:04 The ink can't flow to the ball normally, since gravity doesn't affect it.
28:09 Instead, pressure is created in the ink reservoir, and pens start leaking.
28:14 Some time ago, NASA used pencils, but wooden pencils were considered to be a fire hazard
28:19 in most spaceships.
28:20 All because, at that time, the atmosphere inside them was 100% oxygen.
28:26 The need for a super pen was obvious.
28:28 But whatever the rumors claim, NASA did not create such a pen, spending a fortune on the
28:34 research.
28:35 This development was sponsored by Paul C. Fisher of the Fisher Pen Company, based in
28:39 Chicago.
28:40 He spent over $1 million and almost 10 years to make a pressurized ink cartridge.
28:46 It was supposed to allow space pens to function in zero gravity and other extreme conditions.
28:51 Eventually, they got a pen that could write at a temperature of -30 to 250°F, which is
28:58 really impressive, isn't it?
29:00 The pen was patented in 1966, and one year later, after conducting several thorough tests,
29:06 NASA started to provide Apollo astronauts with such pens.
29:10 Interestingly, the rumors about NASA spending an insane amount of money on the development
29:15 of space pens have been circulating for decades.
29:18 They have been debunked many times, but they appear again and again.
29:23 Many sci-fi movies can make you believe that everything happening in space is accompanied
29:28 by some kind of a sound effect, which is a totally false misconception.
29:33 In space, no one will hear you scream.
29:35 You know why?
29:36 There's no air in space, it's an almost perfect vacuum.
29:40 And sound waves don't travel through a vacuum.
29:43 They can't reach your eardrums and make them vibrate, sending signals to your brain.
29:47 But it's a good thing, especially for astronauts on spacewalks.
29:51 If not for the quietness of space, they would be constantly overwhelmed by the noise of
29:56 solar storms.
29:58 Here's another one.
29:59 All comets have beautiful long tails.
30:02 It's nothing but a popular misconception.
30:04 In reality, comets are very difficult space bodies to spot.
30:08 They usually spend large amounts of time far away from stars.
30:12 There, in the darkness of space, they remain rather inactive and completely frozen.
30:18 Comets only get tails once they come close to a star.
30:21 That's when they start warming up.
30:23 This process makes them form some kind of a cloudy atmosphere, which is called a coma,
30:28 and a distinctive tail.
30:30 The tail always points away from the star that influences the comet.
30:34 It happens because the tail gets blown in the opposite direction by solar radiation
30:39 and solar winds.
30:40 That's why the tail can often be in front of the comet, not trailing after it.
30:45 Now let's look at a light year.
30:48 This very notion makes us believe we speak about time here.
30:51 But in reality, light years measure distance.
30:55 NASA's definition of a light year goes like this.
30:58 The total distance that a beam of light moving in a straight line travels in a year.
31:03 And since light moves at a speed of 186,000 miles per second, a light year equals almost
31:10 6 trillion miles.
31:12 Hey, do the math!
31:14 People often believe that in space, you experience zero gravity.
31:18 Hence the weightlessness astronauts feel on the International Space Station.
31:22 But that's not exactly true.
31:25 Gravity is one of the most important forces that exist in the Universe.
31:29 Thanks to it, the Moon can orbit Earth, and the Sun doesn't float away from our home
31:33 Milky Way galaxy.
31:35 But the astronauts on the ISS experience not full-fledged, but microgravity, which means
31:41 very small gravity.
31:43 The gravity on the space station is only 10% weaker than the gravity on Earth's surface.
31:48 But astronauts are constantly in free fall.
31:51 The spacecraft, the people inside, and all the objects aboard keep falling forward, not
31:56 down, but around our planet, following a specific orbit.
32:00 And since they're all falling together, the crew and the stuff inside seem to be floating.
32:05 That's why astronauts can move things as heavy as hundreds of pounds with their fingertips.
32:11 And even though microgravity is often called zero gravity, they're very different things.
32:17 It may seem as if the Sun is always on fire.
32:20 At least, that's what it looks like in pictures.
32:22 But in reality, our star is a giant ball of gas.
32:26 Hey, I can relate.
32:28 Nuclear reactions happening in its core at all times makes the Sun burn.
32:33 Every second, hundreds of millions of tons of hydrogen are converted into almost as much
32:38 helium.
32:39 During this process, huge amounts of energy are released as gamma rays.
32:44 Then these rays turn into light.
32:46 In other words, the Sun does emit blinding light and incredible heat.
32:50 But it's not actually on fire, because no oxygen is involved in the process.
32:56 A human can explode if they get into open space without a spacesuit.
33:00 Well, contrary to popular belief, taking off a spacesuit during a spacewalk won't be as
33:06 dramatic as it's often pictured in movies.
33:09 A person will lose consciousness due to a lack of oxygen after 15 seconds of being in
33:14 outer space without protection.
33:16 Before it happens, the person should breathe out as much air as possible.
33:20 Otherwise, this oxygen will damage their lungs from the inside.
33:24 Then, without the protection of the spacesuit, which is like a mini-spaceship, the pressure
33:29 inside their body will drop.
33:31 This will cause even more serious troubles.
33:33 And even though this person definitely won't burst, they won't want to stay outside for
33:37 too long.
33:39 Black holes are giant, scary, cosmic vacuum cleaners, they say.
33:43 But in reality, black holes are more like fly traps.
33:47 They don't look for things to munch on.
33:49 Instead, they sit out there quite passively.
33:52 Only when a star comes too close does a black hole spring into action.
33:57 Even so, only those space objects that cross a certain border get ripped apart.
34:02 If the Sun were suddenly replaced with a black hole, Earth's orbit wouldn't change.
34:06 At the same time, Earth's temperature would be different.
34:09 There would be no solar wind, and no magnetic storms created by the Sun would affect our
34:14 planet.
34:15 And let's say the black hole that replaced the Sun had the same mass as our star.
34:19 Then, according to the law of physics, Earth would have to come very close to get pulled
34:24 into this black hole.
34:25 Now, the "dark side" of the moon myth was debunked more than 50 years ago.
34:30 And still, not everyone knows that this dark side is simply part of the Earth's natural
34:35 satellite that faces away from our planet.
34:38 You may think the Earth is pretty big, but the Sun makes up almost 99.9% of the mass
34:44 of the whole solar system.
34:46 The rest of the mass is made up by the planets and their satellites, asteroids, comets, gas,
34:52 and dust.
34:53 It's around 93 million miles away from our planet, but it keeps us warm every day.
35:00 Its temperature is about 10,000 degrees Fahrenheit, but the space surrounding it is still cold
35:05 as ice.
35:06 To understand this, we need to distinguish between heat and temperature.
35:11 Heat is the energy inside some object.
35:14 Temperature is something that tells us if that object is hot or cold.
35:19 When the heat is transferred to that object, it makes its temperature go up.
35:23 When the object is losing heat, the temperature goes down.
35:27 Heat can be transferred in three different ways.
35:30 The Sun does it through radiation.
35:32 That means it's releasing heat in the form of light.
35:35 Our body radiates heat, too, as infrared waves.
35:39 That's why thermal imaging cameras will detect that you're in the room even at night.
35:44 The hotter the object, the more heat it will radiate.
35:47 The temperature only affects matter.
35:50 Since space is mostly a vacuum, it doesn't have enough particles for heat to transfer
35:54 in any other way than through radiation.
35:57 When the heat from the Sun gets to an object, the atoms start absorbing energy, but the
36:02 heat can't transfer since there's no matter in space.
36:06 Those rare atoms and molecules in space will absorb the heat, and they'll simply stay
36:11 that way, while the cold vacuum will stay cold.
36:15 There's a lot of matter inside Earth's atmosphere, so the energy of the Sun can transfer
36:20 easily.
36:21 But if you put an object outside of the Earth's atmosphere in direct sunlight, it would end
36:26 up heated to 250 degrees Fahrenheit, because it's matter made of atoms and molecules.
36:33 The temperature of the vacuum is negative 454 degrees Fahrenheit.
36:38 That means, depending on where you are, space can either burn or freeze you.
36:43 The Sun isn't actually yellow.
36:45 It emits light over a wide range of wavelengths.
36:49 We can tell both its temperature and color by the peak in its spectrum.
36:53 For instance, cooler stars will appear red, and hotter stars will be blue with yellow,
36:59 orange and white stars in between.
37:02 When it comes to the Sun, the spectrum peaks at a wavelength we'd usually call green,
37:07 but our eye perceives it differently.
37:09 So the shade of green in combination with other wavelengths from the spectrum is going
37:14 to look white to the human eye.
37:17 We generally see the Sun as yellow because our atmosphere scatters blue light more efficiently
37:22 than the red one.
37:23 During sunrise and sunset, there's more red light in the spectrum of the Sun, which
37:28 gives us amazing sceneries.
37:31 Sunspots are part of the Sun's visible surface that are on average way cooler than
37:35 the Sun itself.
37:37 They overlap with parts that have an increased magnetic field.
37:41 These parts don't allow the release of heat to the Sun's visible surface.
37:45 That way, the rest of the Sun's surface is three times brighter than those sunspots.
37:51 That contrast makes them appear almost black.
37:55 If we could take a sunspot apart from the Sun and place it somewhere in the night sky,
37:59 it would be different, as bright as the Moon when we see it from the Earth.
38:04 All the planets in our solar system spin in the same direction because they were formed
38:08 from one protoplanetary cloud, except for Uranus and Venus.
38:13 They have probably had some strong impact on them that made them spin in the opposite
38:18 direction.
38:19 But it's different with galaxies.
38:21 They don't usually form the same cloud of dust and particles.
38:24 Also, they're not randomly distributed across space.
38:29 They come in filaments, dense, slender strands of dark matter and galaxies, with voids in
38:35 between.
38:37 Proto-galaxies are linked by gravitational forces in small areas of space.
38:41 This is probably because of the distribution of dark matter throughout the universe.
38:46 The matter in the filaments moves in a corkscrew motion and goes towards the densest area.
38:52 So, there might be a common direction galaxies tend to spin, but it's mostly random.
38:58 There's a possibility we'll see a lunar elevator one day.
39:02 Yep, a cable anchored to the surface of the Moon.
39:05 It would stretch 250,000 miles.
39:08 We wouldn't be able to directly attach it to our planet because both Earth and the Moon
39:13 are moving.
39:15 But we could keep it terminated high in our planet's orbit.
39:19 Some researchers believe we could build such an elevator for a few billion dollars.
39:24 The Moon has resources we could definitely use.
39:27 A rare form of helium found there could be of use in fusion power stations on our planet.
39:33 Also, we could take some other rare elements and use them in smartphones and the rest of
39:38 electronics.
39:39 So, after around 53 trips up and down, the elevator could pay for itself.
39:45 The cable would be as thick as a pencil, but its weight would be around 40 tons.
39:51 It could even be made of materials we already have here on Earth, with no need to invent
39:56 something.
39:57 There could even be a combination of two elevators.
40:00 A spacecraft would winch up an elevator from the surface of our planet to a space station.
40:06 Then it would be flung towards the Moon.
40:09 There would be another elevator to finally lower it down to the surface of the Moon.
40:14 Planets in our solar system have predictable and stable orbits.
40:18 But gas giant collisions could have happened at an early stage when a planetary system
40:23 was still forming.
40:25 In case of a head-on collision, two gas giants would merge.
40:29 They wouldn't end up losing their mass, the materials in their gaseous envelopes, or the
40:33 ones in their solid cores.
40:36 Such a collision at a higher speed would cause the loss of the major part of the envelope
40:41 gas.
40:42 And very high speeds…
40:43 Boom!
40:44 Both planets are gone!
40:45 It's staring at you, and you're staring at it.
40:49 A giant eye that seems to be pulling you into an abyss.
40:52 You're hovering over it in your space copter.
40:56 But however scared you might be, you still need to do your job.
41:00 So you send your copter down to the surface of the Red Planet.
41:03 Right, that's where you are – on Mars!
41:06 But first things first.
41:08 You take a moment to remember everything you know about the 4th planet from the Sun.
41:12 It's the last of the inner planets.
41:14 Those are the planets that lie within the asteroid belt.
41:17 They're also called terrestrial, since they're made up of rocks and metals.
41:21 The atmosphere of Mars is much thinner than Earth's.
41:24 It contains 95% carbon dioxide and a mere 1% of oxygen.
41:29 In other words, don't even think about pulling off your helmet.
41:33 Anyway, there's no time to waste.
41:35 You land on the surface of the planet and find yourself in a brownish-red world.
41:39 That's a good thing you're wearing a spacesuit – this place is freezing cold!
41:44 The thermometer sewn into the sleeve of your suit shows -80°F.
41:50 Time to take your first step on the Martian surface.
41:53 The planet looks quite colorful, and the hue of a particular area depends on the minerals
41:58 that make up the soil.
42:00 The ground under your feet is covered in fine dust.
42:03 It looks like rust.
42:04 The same orange dust is in the air.
42:07 Good thing you have your own supply of oxygen and don't need to breathe Martian air.
42:11 The layer of this dust covering the surface of Mars can be from 6 to 40 feet thick.
42:17 You hope you'll avoid getting swallowed by some Martian quicksand.
42:21 You start walking, feeling very light.
42:24 Mars is just 15% of our planet's volume and a mere 11% of Earth's mass.
42:29 It means that gravity here is much weaker – its pull is 38% as strong as the pull
42:34 of gravity on the surface of Earth.
42:37 You jump up and down and then try to run several hundred feet.
42:41 You haven't even broken a sweat!
42:43 What makes it harder for you to explore the place on foot is that the planet's surface
42:48 is rocky, covered with craters and volcanoes, old dry lake beds, and canyons.
42:54 You see something huge towering on the horizon, but you try to suppress your curiosity.
42:59 You'll have enough time to figure out what it is later.
43:03 Suddenly, a massive cloud appears in the distance.
43:06 It looks as if a huge herd of horses is approaching you.
43:10 In reality, you'd better get back into your copter and fly away as fast as you can.
43:15 That's one of Mars' infamous dust storms.
43:18 They mostly occur during the summer in the southern hemisphere of the Red Planet.
43:22 They can sometimes cover the entire planet.
43:25 And you see the largest ones from Earth!
43:28 You hop into your copter and set a course for the eye that scared you so much.
43:32 Winding channels that look like veins run through the eyeball.
43:36 But the closer you get, the less it looks like an actual eye.
43:40 Then you realize it's a crater – it's giant, almost 19 miles across!
43:46 Around the crater, which looks as if it has a pupil, there are other even bigger craters.
43:51 They likely formed billions of years ago.
43:54 That's when Mars had to withstand multiple attacks of space rocks.
43:58 But why is the eye crater darker than the surrounding landscape?
44:03 Scientists think that once, there was Martian water in the enormous pit.
44:07 Under those channels, they were likely carrying that water.
44:11 And since the crater was filled with water, it stopped some substances and minerals from
44:15 eroding away.
44:17 Now, remember that towering something on the horizon?
44:20 It's time to go and explore it!
44:23 When you come close, you realize it's the largest shield volcano in the entire Solar
44:28 System – Olympus Mons.
44:30 It's more than 370 miles in diameter, which is almost the same size as the state of Arizona!
44:37 You tilt your head – wow!
44:39 The mountain is 16 miles high!
44:42 It's also rimmed by 4-mile-high cliffs.
44:45 To picture the sheer size of the volcano, let's make some comparisons.
44:49 The largest volcano on Earth is Mauna Loa, towering around 2.5 miles above sea level
44:55 and stretching 75 miles across.
44:58 Sounds impressive, but the volume of Olympus Mons is around 100 times larger than that
45:04 of Mauna Loa.
45:05 The Martian giant could swallow the whole chain of Hawaiian islands from Kauai to Hawaii.
45:11 But why is this volcano so large?
45:14 It might be the result of lower surface gravity and higher eruption rates.
45:18 Or the reason might be the Red Planet's crust, which is very different from Earth's.
45:23 It's static.
45:24 You see, on our planet, the crust is made of 15-20 moving tectonic plates.
45:30 Those plates move over hot spots, producing lava, new volcanoes form, and the already
45:35 existing ones become extinct.
45:37 That's why lava can get to the surface through many vents.
45:41 But on Mars, the crust isn't broken into the same tectonic plates as on Earth.
45:46 And the lava has nothing to do but pile in one very, very large volcano.
45:53 So how about getting closer to the enormous mountain?
45:56 But once you step out of your copter on Martian soil, the ground under your feet starts shaking.
46:02 Well, that's a Marsquake.
46:04 But how can it happen if Mars doesn't have any actively shifting tectonic plates?
46:09 Specialists from NASA are sure Marsquakes occur when energy inside the planet gets suddenly
46:15 released.
46:16 It leads to rock fractures and cracks in the planet's crust.
46:20 Another powerful jolt, and one of such cracks opens right next to you.
46:25 You fall to the ground, afraid to move, but soon, everything calms down.
46:30 You wait for a couple of minutes, just to be sure, and get up.
46:34 Oh look, here's a perfect opportunity to explore the insides of the Red Planet.
46:39 The crack is large enough to send a special research robot.
46:43 The planet's crust is thin and consists of volcanic basalt rock.
46:48 The mantle that surrounds the core of the planet is made up of thick silicates, oxygen,
46:53 and some minerals.
46:54 You can probably compare it with soft, rocky toothpaste.
46:57 Mars' mantle is also much thinner than Earth's.
47:01 It's just 800 to 1100 miles thick.
47:04 As for the planet's core, it's made mostly of iron, nickel, and sulfur and is between
47:09 900 and 1200 miles wide.
47:12 This core doesn't move.
47:13 That's why Mars doesn't have a planet-wide magnetic field.
47:18 Unfortunately, your drone is now lost in the depths of the Red Planet.
47:22 You leave it there and continue your exploration.
47:25 Your next destination is Valles Marineris.
47:28 It sounds more like an Italian red sauce, but it's actually an enormous canyon, or
47:33 rather a canyon system, that runs along Mars' equator.
47:37 It's as awe-inspiring as Olympus Mons, more than 2,600 miles long and over 4 miles deep.
47:44 The thing is so huge, it could span the entire continental United States from the Pacific
47:49 to the Atlantic Ocean.
47:50 That's it for today!
47:52 So hey, if you pacified your curiosity, then give the video a like and share it with your
47:56 friends!
47:57 Or if you want more, just click on these videos and stay on the Bright Side!