Moon Facts That Will Make You Crave a Lunar Liftoff

Bright Side

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Transcript

00:00:00People stop their cars on the highway, get out of them, and lift their heads in wonder.

00:00:05In the cities, everyone takes to the streets.

00:00:08Balconies and rooftops of houses are full of people staring at the moon in shock.

00:00:13It's red.

00:00:14Some people scream that it's the end of the world.

00:00:17Some seek shelter.

00:00:19Indeed, the usual white moon now looks like it's been doused in red paint.

00:00:24There's no need to be afraid if you see such a thing.

00:00:27On the contrary, enjoy the view.

00:00:29Because you have witnessed a rare astronomical phenomenon.

00:00:33This is a total lunar eclipse.

00:00:36Here's the sun.

00:00:37It's in the center of our solar system.

00:00:39Mercury, Venus, and here's Earth and the moon.

00:00:43The Earth takes 365 days to orbit around the star.

00:00:47At the same time, the moon revolves around the Earth and completely orbits our planet in 27 days.

00:00:53The Earth creates a shadow zone, and sometimes the moon passes through it.

00:00:58The shadow is cone-shaped and gradually narrows.

00:01:02The moon is 238,000 miles away.

00:01:05That's like nine lengths of the equator.

00:01:07At this distance, the width of the shadow is about 2.6 times the width of the moon.

00:01:14When the moon is in this zone, direct sunlight doesn't reach it.

00:01:18That is, it should have disappeared.

00:01:20But instead, it becomes red.

00:01:23All because the sun's rays pass through the Earth's atmosphere.

00:01:27They scatter, and most of the blue light disappears.

00:01:30But the red and orange rays continue and hit the surface of the moon.

00:01:35Voila!

00:01:36You see a phenomenon called the blood moon.

00:01:39By the way, this curvature of light occurs at sunsets and dawns.

00:01:44The atmosphere scatters the blue light, and you see a red and orange sky.

00:01:49If you were standing on the surface of the moon during a total lunar eclipse,

00:01:53planet Earth would be exactly between you and the sun.

00:01:56So, you would be able to observe the solar eclipse.

00:02:00The surface of the Earth would become entirely dark for you.

00:02:03All you'd see would be the sun's corona illuminating the edges of the planet.

00:02:08The Earth from the surface of the moon is almost the same size as the moon from the surface of the Earth.

00:02:15Such a red eclipse of the moon is rare because several factors must coincide.

00:02:20One of them is that the moon must be full.

00:02:23Usually, you can see two total lunar eclipses a year.

00:02:27In 2038, you'll be able to see four such eclipses.

00:02:31And the eclipse itself can last up to 108 minutes.

00:02:35But this is rare, and the last time such a long blood moon was seen was in 2000.

00:02:41Many years ago, people didn't know so many facts about our satellite,

00:02:45and the sight of a red moon frightened them.

00:02:47It was a bad sign and a harbinger of trouble.

00:02:51People who knew the schedule of eclipses could take advantage of it.

00:02:55For example, Christopher Columbus had an astronomical almanac

00:02:59and knew when the next lunar eclipse would occur.

00:03:02He frightened the inhabitants of the Caribbean islands when he predicted the red moon.

00:03:09Once upon a time, the moon used to be a red ball of lava.

00:03:12This was way back in time, 4.5 billion years ago.

00:03:16Now, this is our solar system.

00:03:18It's full of dust and asteroids.

00:03:20They're constantly bumping into each other, playing space billiards.

00:03:24This is Earth.

00:03:25It's just beginning to cool off from the constant asteroid and comet impacts.

00:03:29But then, Theia appears on the horizon, a planet the size of Mars.

00:03:35It had a chaotic orbit and was approaching Earth in a spiral.

00:03:39A collision was inevitable,

00:03:41and at one point, one of the biggest crashes in our solar system occurred.

00:03:45Theia struck the Earth at an angle.

00:03:48It ripped out part of the Earth's crust and threw it into space.

00:03:51The Earth, in turn, absorbed part of the planet that rammed it.

00:03:55The debris from the collision circled the Earth for a long time.

00:03:59They were a kind of ring, almost like Saturn's.

00:04:02Debris in orbit collided and piled up around a common center of gravity.

00:04:07And that's how the Earth got the moon.

00:04:10There's a theory that this collision helped give birth to life on our planet.

00:04:14Theia hit the Earth at a perfect angle.

00:04:17If the crash had been head-on,

00:04:19both planets would likely have been destroyed in a massive explosion.

00:04:23If the impact had been tangential,

00:04:26then there wouldn't have been enough debris in Earth's orbit to form the moon.

00:04:30But we got the lucky ticket.

00:04:32The moon stabilized the Earth's rotation.

00:04:34The collision shattered the planet's solid crust and allowed oceans to form.

00:04:39Remember, water is the basis of life.

00:04:42When the cores of Earth and Theia merged,

00:04:45we got a powerful magnetosphere.

00:04:47This protects all living organisms from solar radiation.

00:04:51The moon, along with the sun, controls the tides.

00:04:55Its gravity seems to draw water to it from the Earth's surface.

00:04:58The sun does the same thing.

00:05:00That is, if we imagine the Earth as a ball of water,

00:05:04there would be two mountains,

00:05:05one on the moon's side and one on the sun's side.

00:05:09And as the moon moves around the Earth,

00:05:11this mountain of water moves with it.

00:05:14If you were in the open ocean with a tape measure,

00:05:16you would see that the moon is attracting water to itself by about 4 to 6 inches.

00:05:22The moon is gravitationally locked with the Earth.

00:05:25That's why it's always turned to us with one side, like Mercury and the sun.

00:05:30But the moon doesn't stand still.

00:05:32It's gradually moving away from our planet, about 1.5 inches a year.

00:05:37Not quickly, but in about 600 million years,

00:05:40it will have shrunk in our sky so much

00:05:42that we won't be able to see lunar eclipses anymore.

00:05:46Do you see this crater?

00:05:47It's Tycho.

00:05:48It's visible during a full moon because of these bright rays

00:05:51that extend thousands of miles from its epicenter.

00:05:54This is the youngest crater on the moon.

00:05:57Scientists say it appeared there due to a meteorite impact about 109 million years ago.

00:06:03At that time, dinosaurs were roaming the surface of our planet,

00:06:06and they may have seen the impact.

00:06:09It was most likely accompanied by a big explosion

00:06:12and looked like a salute in the night sky.

00:06:15Humanity loves to explore the moon.

00:06:18We've sent a bunch of missions there.

00:06:20A total of 12 people have set foot on the surface of the moon.

00:06:24The gravitational force there is six times less than on Earth.

00:06:27So, if the average person on our planet weighed about 180 pounds,

00:06:32on the surface of the moon, the scales would only show 30 pounds,

00:06:36like the weight of an average dog.

00:06:38That's why the astronauts moved, jumped, and fell so strangely there.

00:06:43And you would be six times stronger on the surface of the moon.

00:06:47Here on Earth, the average person could lift about 130 pounds.

00:06:51But on the moon, you could raise a big motorcycle or a grizzly bear.

00:06:56The surface of the moon is covered with regolith.

00:06:59This is the lunar dust that covers the solid ground.

00:07:02Such dust is good at preserving footprints.

00:07:05Here's the most famous footprint, which gave birth to many crazy theories.

00:07:10Here's the footprint, and here's the shoe that left it.

00:07:14But the shoe is completely flat.

00:07:16This is explained simply.

00:07:18The astronauts wore extra boots for walking on the lunar surface.

00:07:21They have exactly the kind of sole that left these marks.

00:07:25In addition to the footprints, we left many fascinating objects on the moon.

00:07:29Several lunar rovers, a golf ball, flags, and human waste.

00:07:34There's also a lot of broken satellites and rocket parts.

00:07:38All in all, about 413,000 pounds of human-made objects are there.

00:07:43That's the weight of three passenger planes or 31 adult elephants.

00:07:48In the future, we plan to resume missions to the moon.

00:07:51New landers will explore the surface of our satellite to find natural resources there.

00:07:56It's also a great place to test new rovers.

00:07:59We're even going to build something like the International Space Station in the moon's orbit.

00:08:03The Lunar Orbital Platform Gateway.

00:08:06It'll be a convenient platform for exploring our satellite and launching spacecraft into distant space.

00:08:12If you start from here, the spacecraft won't need to spend almost all its fuel to overcome the force of Earth's gravity.

00:08:19So such a station would save fuel and money.

00:08:23Scientists hope that we'll be able to mine water from the moon's surface.

00:08:27It's been proven that there's ice there, mostly at the bottom of craters where the sunlight doesn't reach.

00:08:32Perhaps we'll send a rover there that can drill down a few feet into the surface, searching for water.

00:08:38Humanity already has the technology to build a full-fledged colony there.

00:08:42It would take up to three days to get there.

00:08:45We just need to get enough solar panels and building materials to the moon.

00:08:50There's no atmosphere on the moon, so potential lunar inhabitants would be defenseless against solar radiation.

00:08:56We would have to build houses underground to provide protection.

00:09:00Modern 3D printers will help make construction easy and fast.

00:09:04However, food and water supplies can only be maintained by constant supplies from Earth.

00:09:09The same goes for oxygen.

00:09:11Each rocket launch costs millions of dollars, so for now, colonization of the moon is in question.

00:09:18The moon could also become an object for space tourism.

00:09:22Imagine a spaceship launches from Earth.

00:09:24Three days on the road, and you're orbiting the moon.

00:09:27The lunar module undocks, and you land on the surface.

00:09:31You ride the rover, explore the craters, then return to the lander.

00:09:35The engines start.

00:09:36The lander returns you to orbit.

00:09:39You dock with the ship and return to Earth.

00:09:41Sounds like some pretty great plans for a week's vacation.

00:09:47Soon we might start constructing loads of stuff on the moon.

00:09:52All because India's moon mission has recently detected sulfur near the moon's south pole.

00:09:59This chemical element can come in extremely handy for creating infrastructure on our satellite.

00:10:06It's the first time this chemical element has been discovered on Earth's natural satellite.

00:10:12This sought-after element is mostly found near Earth's volcanoes.

00:10:17Its appearance on the moon speaks volumes about the satellite's volcanic history

00:10:21and its past atmospheric conditions.

00:10:26The mission's rover detected this chemical element less than a week after touching down

00:10:30around 70 degrees from the moon's south pole on the 23rd of August, 2023.

00:10:37This historic landing on the lunar surface made India the fourth country to safely land a mission on the moon.

00:10:46It's also the first spacecraft to touch down so close to the south pole of our satellite.

00:10:51It's an area of strategic importance because it's believed to be home to deposits of water ice.

00:10:58If it turns out to be true, future missions might be able to harvest it

00:11:02and turn this water ice into drinking water or even rocket fuel.

00:11:08For two weeks, the lander carried out the data collection,

00:11:11mainly focused on the analysis of the moon's soil and its extremely thin atmosphere.

00:11:18Meanwhile, the solar-powered Pragyan rover started its quest to find frozen water on the moon.

00:11:24As for the lander, it demonstrated another amazing feat on the 3rd of September.

00:11:29The spacecraft fired up its engines and lifted itself for about 16 inches into the air.

00:11:36Then it made a tiny hop to land 12 to 16 inches away from its original position.

00:11:41It's kinda a big deal.

00:11:44Being able to get a lander back off the surface of the moon is essentially for future missions,

00:11:49showing that they can safely return soil samples or even astronauts back home after a lunar mission.

00:11:58In September, the Indian spacecraft was put into sleeping mode.

00:12:02The 14-day-long lunar night was approaching,

00:12:06and the spacecraft wasn't designed to collect scientific data during this period of time.

00:12:11So far, we've learned about a few major findings of the mission.

00:12:16One is related to measuring the temperature of the moon's topsoil at different depths.

00:12:21Intriguingly, the surface of the satellite in that region turned out to be hotter than expected.

00:12:27It was believed that the temperature could be between 68 and 86 degrees Fahrenheit on the surface,

00:12:34but it was around 158 degrees Fahrenheit, way hotter than it should be.

00:12:41The other discovery indicates the presence of several chemical elements, including oxygen.

00:12:47Besides, the data received from the spacecraft confirms the presence of aluminum,

00:12:52calcium, iron, titanium, silicon,

00:12:56and other chemical elements on the lunar surface close to the South Pole.

00:13:01The rover also used special instruments designed to measure quakes

00:13:06and rumbles beneath the lunar surface to detect some seismic activity.

00:13:11It brings us back to the sulfur detected thanks to the rover's spectroscope.

00:13:17Scientists are currently working on figuring out whether this element formed on the surface in a natural way,

00:13:23or whether it's the result of volcanic activity or a meteor strike.

00:13:29Another astonishing thing found on the moon is a rock, and it may be the oldest known Earth rock.

00:13:36A 0.7-inch-wide chip included in a large rock collection brought to our planet by Apollo astronauts

00:13:43might actually be a 4-billion-year-old fragment of Earth.

00:13:49This finding could help us paint a better picture of the intense pounding early Earth got at the dawn of its life.

00:13:58It could go like this. Soon after the rock formed, an asteroid impact might have blasted it from Earth.

00:14:04At that time, our planet's satellite was three times closer to Earth than it is today.

00:14:11The collision was so powerful that this chunk of terrestrial rock found its way to the moon.

00:14:16Later, this fragment got engulfed in a lunar breccia, a motley kind of rock.

00:14:22Eventually, the rock was brought back home to Earth by Apollo 14 astronauts.

00:14:28Even though scientists had found meteorites coming from Mars and the moon before,

00:14:32it was the first time a rock from the moon turned out to be a terrestrial meteorite.

00:14:37They also found out that the rock had formed in a water-rich environment at temperatures and pressures

00:14:43corresponding to those at around 12 miles beneath the surface of our planet.

00:14:51In 2019, China's Chang'e-4 mission made history by landing on the far side of the moon.

00:14:57The mission's rover helped researchers visualize structures hidden deep below the surface of the satellite,

00:15:04revealing billions of years of lunar history.

00:15:07The Yutu-2 rover made this discovery with the help of its lunar-penetrating radar.

00:15:13It imaged deep into the moon's surface and listened to echoes of sound bouncing back off structures

00:15:20hidden from view under the surface of the moon.

00:15:24It turned out those structures were resting at depths of almost 1,000 feet.

00:15:29The research suggests that the first 130 feet under the surface are made up of layers of dust, soil, and rocks.

00:15:37The instruments also discovered a concealed crater that must have formed after a large object slammed into the moon's surface.

00:15:45Long, long ago, ancient lava was likely to be flowing deep underground.

00:15:52Researchers believe that the broken rocks around the formation might be debris produced by the impact.

00:15:58They also found that the volcanic rock layers were thinner the closer they were to the surface.

00:16:04Such a thickness variation of lava flows might mean a decrease in the number and magnitude of eruptions over time.

00:16:12So, lunar volcanic activity gradually dwindled since the moon's formation around 4.5 billion years ago.

00:16:22On the far side of the moon, there is one of the largest and oldest impact craters in our solar system, the South Pole-Aitken Basin.

00:16:31Unfortunately, from Earth, you can only see its outer rim, which looks like a huge chain of mountains.

00:16:38It's a ginormous 8-mile-deep dent, stretching for more than 1,500 miles in diameter and covering one-fourth of the moon's surface.

00:16:48Astronomers are sure that this crater appeared when an asteroid collided with the moon around 4 billion years ago.

00:16:56And now, look at this gigantic chunk of metal the size of four states of Connecticut.

00:17:02As for its weight in pounds, it's enough to say that the number contains 18 zeros.

00:17:08This mysterious mass is hidden about 180 miles under the moon's surface, somewhere in the middle of the South Pole-Aitken Basin.

00:17:18It was discovered when GRAIL, which stands for NASA's Gravity Recovery and Interior Laboratory Mission, gathered data about our natural satellite.

00:17:28When examining this information, scientists noticed that in one place on the moon's surface, there was a weird change in gravity.

00:17:36After researching this phenomenon, they included that something mysterious was weighing down the basin floor there.

00:17:44So far, researchers haven't figured out the origin of the bizarre lump, but there are several theories.

00:17:51One of them claims that the finding is a chunk of dense oxide, which appeared when the moon was just taking its shape.

00:17:58At that time, the satellite was still covered with ancient oceans of magma, and the lump could be formed at the final stages of its cooling.

00:18:06However, most scientists support another theory, according to which the puzzling mass is part of the giant asteroid that once created the South Pole-Aitken Basin.

00:18:17Since the thing is metallic, it's probably the iron-nickel core of the asteroid.

00:18:24There might be a labyrinth of lava tubes on the moon.

00:18:27Not so long ago, astronomers received the results of underground topography and discovered a massive cave under the surface of Earth's satellite.

00:18:36It could be the result of the lunar volcanic activity that happened more than 3 billion years ago.

00:18:43Streams of lava hardened, creating a thick, hard crust on the outside.

00:18:49But inside, it kept flowing, melting the rock and creating tunnels and caves.

00:18:55Numerous small pits in the moon's surface discovered by NASA seem to be the openings to such lava tubes.

00:19:02If this theory is confirmed, the underground tunnels might serve not only as a convenient location for human-crewed space missions, but also as much-needed water sources for astronauts.

00:19:16How about playing golf, not on Earth, but on the moon?

00:19:20Let's journey back to a time 50 years ago, when one astronaut turned the lunar surface into the most unusual golf course ever.

00:19:30Any golfer will tell you how tricky it is to avoid sand traps.

00:19:34But picture Alan Shepard, a NASA astronaut dealing with an entire surface that feels like super-fine powder.

00:19:41During the Apollo 14 mission, he took a break to showcase some spacey golf skills for everyone watching from Earth.

00:19:48After his first shot, he excitedly made another.

00:19:51For him, it seemed the ball went forever and ever.

00:19:56Let's dial back to reality for a moment.

00:19:59Thanks to the research by the United States Golf Association, or USGA, we've got some numbers.

00:20:05They found that Alan's first moon ball traveled 24 yards, and his second stretched for 40 yards.

00:20:12Now, how does that compare to the average golf shots back here?

00:20:16In regular gravity, one usually swings to about 216 yards.

00:20:21Just goes to show, while we've upgraded our golf game on Earth with tech and training,

00:20:26the moon's low-gravity playground is a different environment altogether.

00:20:34Now, let's give Alan some props.

00:20:36Moon golf? Not as simple as you might think.

00:20:39His club wasn't one from your local sports store, it was a makeshift one.

00:20:43A moon sample collector with a club head stuck to it.

00:20:46Add to that the bulky spacesuit he had on.

00:20:49Imagine trying to swing wearing an outfit that's as stiff as cardboard.

00:20:54With all that gear, Alan could only muster a one-handed swing.

00:20:58Care to have a similar experience?

00:21:00Well, you might not be able to play golf on the moon anytime soon, but you can give it a shot underwater.

00:21:07Some say the conditions are similar.

00:21:11Here's where it gets even more interesting.

00:21:14The USGA didn't just take Alan's word on where the balls landed.

00:21:18They wanted to investigate.

00:21:20For starters, they used ultra-clear footage of the Apollo 14 mission.

00:21:25They also used some sharp images from NASA's special moon camera, launched in 2009.

00:21:31Using this imagery, they mapped out the journey of those two golf balls.

00:21:37Alan loved his unique golf club so much, he wanted to bring it back home.

00:21:43No big deal, right?

00:21:45Well, you see, in those days, astronauts would leave behind unnecessary items to make space for moon rocks.

00:21:51But not this club.

00:21:53So during the 70s, this interstellar golf club found a new home at the USGA Museum in New Jersey.

00:21:59Unlike regular golf clubs, this one had a twist.

00:22:03It was crafted from aluminum and Teflon.

00:22:05It was built to fold and fit snugly within the tight spaces of the lunar lander.

00:22:11How did this whole moon golf idea even pop up?

00:22:14Well, in 1970, golf legend Bob Hope paid a visit to NASA.

00:22:19Inspired by Hope's love for golf, an idea came into Shepard's head.

00:22:23Moon golf!

00:22:25To turn his dream into reality, he collaborated with a golf professional and NASA's tech specialists.

00:22:31Together, they crafted a club that met NASA's strict safety norms.

00:22:39But hey, Alan didn't want this to be just a surprise stunt.

00:22:42Remember, traveling to the moon required very strict protocols.

00:22:46They couldn't just randomly have a picnic up there, you know.

00:22:49So, Alan made sure NASA officials agreed with this impromptu game of golf.

00:22:54They were initially skeptical, but eventually gave the green light after Alan passionately laid out his plan.

00:23:00He also promised he'd start playing if everything went smoothly on the mission.

00:23:06Determined to make it perfect, Alan prepped like a champ.

00:23:09The story goes that he'd put on his hefty space suit and sneak off to secret spots so he could practice.

00:23:15Decades later, he'd still be reflecting on his lunar escapade.

00:23:19He was the only golfer to ever swing on the moon.

00:23:23It's not just golf balls that astronauts left behind on their trips.

00:23:27There were actually a lot of objects left on the moon between 1969 and 1972, the year of the last moon landing.

00:23:39Each time you gaze up at the moon, remember that there's a cute family photo up there,

00:23:43some huge science gadgets, a small statue, a bunch of, well, human waste bags, and yes, some American flags.

00:23:52Years have passed by, and yes, technically those items are still hanging out there,

00:23:57though they've probably seen better days because of the harsh conditions on the moon.

00:24:01Some items had a special place in the astronauts' hearts and were meant to stay on the moon.

00:24:06But hey, leaving some stuff behind also meant they could bring back moon samples.

00:24:11You know the feeling. It's like when you need to make room in your suitcase for souvenirs when you're finishing a vacation.

00:24:18Does NASA have a complete list of things they left on the moon?

00:24:21Well, not really.

00:24:23In fact, one team tried to create a record of some of the items and reached an amazing list of 106 left there from the Apollo 11 mission alone.

00:24:33That's not counting Neil Armstrong and Buzz Aldrin's famous footprints.

00:24:38The largest items at each landing site were mostly the science-y stuff, like pieces of their lunar module and experiments to study the moon in depth.

00:24:48Then there were some beautiful tokens, like Apollo 11's plaque and a special disc with messages from leaders around the world.

00:24:56Some say the astronauts also took medals to remember some heroic cosmonauts, and they even left a gold olive branch, an age-old symbol of peace.

00:25:07Now, later moon missions had a little more fun, like Alan Shepard did with his golf game.

00:25:12But the award for the most heartwarming moment goes to Charlie Duke.

00:25:16During the Apollo 16 mission, he left a picture of his family up there.

00:25:20It's like he wanted them to be a part of the adventure.

00:25:23Although, a heads up, those photos probably didn't age well because of the moon's high exposure to the sun's radiation.

00:25:30There might just be an art museum up there on our satellite, too.

00:25:34Let me explain.

00:25:35There is this tiny little art piece called the Moon Museum.

00:25:39It's a ceramic chip about the size of your nail, and it was crafted by an artist named Forrest Myers.

00:25:48This tiny object showcases miniature artworks from six talented people.

00:25:53Among them are even the famous Andy Warhol, the same artist known for his iconic soup cans and celebrity portraits.

00:26:01Forrest Myers said he wanted his mini museum to be on the moon, but there was a problem.

00:26:06NASA officials weren't exactly on board with the idea.

00:26:10However, Myers shared with the press that he handed over this art chip to an engineer working on the Apollo 12 mission.

00:26:18According to Myers, this engineer secretly tucked the Moon Museum onto a leg of the lunar lander.

00:26:24In case you haven't figured it out yet, these lunar landers don't come back to Earth after their mission.

00:26:30Take this with a grain of salt, though, as NASA has never confirmed this story.

00:26:34You might wonder, why did they leave all these things?

00:26:38Sometimes it was about making a statement, other times it was purely practical.

00:26:43At one point, it was mentioned that during the Apollo 11 mission, for example, a decision needed to be made.

00:26:50The astronauts had to quickly figure out what was essential for their trip back home.

00:26:55They ended up creating a clean-up spot, tossing away things they didn't need anymore.

00:27:03Leaving things behind on the Moon isn't that different from how we leave things behind on Earth,

00:27:08just like archaeologists study our ancient leftovers to learn about our ancestors.

00:27:13The stuff on the Moon gives us insights about those incredible lunar missions.

00:27:18Some things they left had done their job, like the pole for the flag or the camera they used to broadcast those steps on the Moon.

00:27:24Even the tools astronauts used to collect samples were left because they had more precious cargo to bring back.

00:27:30Moon rocks.

00:27:32When it comes to the current state of all these items, scientists are not entirely sure.

00:27:37We do know that NASA's Moon Observer has spotted some of their shadows.

00:27:41They're still up there.

00:27:43The official gear was built to resist, so it might behave a bit better.

00:27:47But those personal items? They've probably seen better days.

00:27:52It's been decades since the last manned Moon landing, Apollo 17, which happened in December 1972.

00:28:01Isn't it time we thought about going back to our dusty satellite?

00:28:06And maybe even staying there?

00:28:08NASA has made a promise on this subject.

00:28:11They're preparing to send astronauts on the Moon again, perhaps by 2025.

00:28:17This will all happen through a program called Artemis.

00:28:21It's also going to include the first woman ever to experience the lunar surface.

00:28:27Now you might ask, why haven't we done this already?

00:28:32One former NASA administrator said something interesting on the subject.

00:28:36It's not because of scientific or technological issues.

00:28:40Problem was that the potential projects took too long and were just too costly.

00:28:48You see, space travel, especially when it involves humans, isn't easy on the pockets.

00:28:54It's true that, in recent years, NASA had budgets of billions of dollars.

00:29:00Sure sounds like enough money, right?

00:29:03Well, not when you check out their to-do list.

00:29:06That's because they have to consider everything.

00:29:09From telescopes and giant rocket projects to missions also targeting the Sun, Jupiter, Mars and beyond.

00:29:17When you look at it this way, NASA needs to be very good at budgeting to achieve all those goals.

00:29:24It's not just because of finances, though.

00:29:27The Moon itself is quite problematic.

00:29:29It poses real dangers that cannot be taken lightly.

00:29:33For starters, its surface is filled with craters and boulders that aren't easy to land on.

00:29:38Then, there is the Moon dust, or regolith, if you'd like to call it by its scientific name.

00:29:45It was created over many years by meteorite impacts.

00:29:49It's extremely harsh and sticks to everything.

00:29:53It can potentially damage spacesuits, vehicles and systems quite quickly.

00:29:58Also, dealing with the lunar habitat isn't a walk in the park either.

00:30:03The Moon has no protective atmosphere.

00:30:06What this means is that for 14 days at a time, the lunar surface is faced with harsh rays from the Sun.

00:30:13That period is followed by another two weeks of total darkness.

00:30:17All these changes create extreme temperatures, which us humans are not really accustomed to.

00:30:24There are solutions, don't worry.

00:30:26NASA is working on dust and Sun-resistant spacesuits and vehicles.

00:30:31They're even developing a system that might supply electricity during those lunar nights.

00:30:36What's even more interesting about this system is it could come in handy on Mars too, once we get there.

00:30:44NASA also needs to draw in really smart people for its projects.

00:30:49Think about it.

00:30:50The average age of the people working for the mission control for Apollo 13 was just 26 years old.

00:30:58And these people had already been part of numerous missions by that time.

00:31:02Which means they'd had considerable experience from a very young age.

00:31:09But here's where other individuals can help too.

00:31:12In recent years, it wasn't just NASA who's been working tirelessly to revolutionize space travel.

00:31:19There are many successful people out there with enough resources to join in on these efforts.

00:31:25Some are developing new types of rockets that can land on the Moon too.

00:31:31In total, NASA landed 12 people on our satellite.

00:31:35It's definitely one of the most awesome moments in its history, if not the best.

00:31:40And those astronauts did amazing things up there.

00:31:43They brought back rocks, took snapshots, did science experiments and even left flags behind.

00:31:52These were all important moments of the Apollo missions.

00:31:56But they weren't meant to create a safe place for humans on the Moon.

00:32:01Scientists have had this idea of a lunar space station for a long time now.

00:32:06It's only logical.

00:32:08After all, it's just a three-day trip from Earth.

00:32:11It means we can, technically, afford to make little mistakes here and there, without messing up the whole project.

00:32:18Plus, we'd learn so much before venturing even further into space.

00:32:24A Moon base could provide fuel for deep space missions.

00:32:28We could also build telescopes up there and launch them way easier in space.

00:32:33It could also help us in another important project.

00:32:37Figure out how to make Mars habitable too.

00:32:40Not to mention, a lunar space station would help us learn more about the Moon's origin.

00:32:46Who knows, it could even bring in some money because of all that fun, exciting lunar tourism.

00:32:54Either way, the Apollo Moon program took a lot of work.

00:32:58For starters, let's look at the sheer number of people involved.

00:33:02Around 400,000 from every corner of the states.

00:33:07Not everything was picture-perfect.

00:33:10Tough.

00:33:11There were two main unfortunate events.

00:33:14Firstly, a fire mishap at the launch pad of Apollo 1.

00:33:18Secondly, an oxygen tank decided to throw a tantrum on Apollo 13, causing severe issues mid-mission.

00:33:28An important part of the project was Saturn V.

00:33:31It is, to this day, the most powerful rocket flown successfully, being 36 stories high.

00:33:38Still finding it hard to picture?

00:33:41This rocket stood twice as tall as Niagara Falls.

00:33:46Thanks to Saturn V, NASA successfully completed 13 missions.

00:33:51This included chauffeuring 24 astronauts towards the Moon, with half of them even having a little walk on its surface.

00:34:00The existing rockets and space shuttles can't go beyond low Earth orbit.

00:34:04In simpler terms, they can't reach the Moon with all the gadgets astronauts need to thrive.

00:34:11Current space vehicles are just not capable of carrying that load, at least not since the Apollo missions happened.

00:34:18Regardless, we did make a lot of progress on Earth, and are ready to send astronauts to our satellite pretty soon.

00:34:26Here's where the Artemis project comes in.

00:34:29It's a program overseen by NASA.

00:34:32And to make sure it all goes well, NASA previously launched Orion,

00:34:37a spacecraft with no crew on board to orbit the Moon and return to Earth.

00:34:43Think of it as an automated test drive.

00:34:46Before we actually send people out there again, we need to make sure all the devices work properly.

00:34:53One day, Orion will be the vehicle that will take astronauts to the Moon again.

00:34:58It features a launch abort system to keep astronauts safe in case something bad happens during launch.

00:35:05It also has a service module, which is the powerhouse that fuels and propels Orion

00:35:10and keeps astronauts alive with water, oxygen, power, and temperature control.

00:35:17All these future projects make one wonder.

00:35:20What will life on the Moon be like anyway?

00:35:23We can only use our imagination for now.

00:35:26Some say we'll be living in homes straight out of a fairy tale, something like a cozy hobbit hole.

00:35:33Living underground on the Moon might be a must.

00:35:36That's due to the scorching temperatures and the lack of oxygen.

00:35:41If you add meteorite threats and the non-stop radiation, it's no wonder we can't just walk on its surface.

00:35:49What about transportation?

00:35:51Big and small companies alike are trying to create the ideal Moon ride.

00:35:56If current estimations are current, one type of Moon taxi will take off as soon as 2024.

00:36:03Unlike our current rockets, these space taxis won't have to deal with the harsh conditions of re-entering Earth's atmosphere.

00:36:11It will be easier for them to make multiple round trips.

00:36:14To support our lunar living, we'll need to have a special area for space taxis to safely take off and land.

00:36:22Think of it as a landing pad on a firm, flat stretch of Moon surface, protected by walls to shield against Moon dust.

00:36:33Moving around on the Moon's surface will be made easier too.

00:36:37The next generation vehicles we're talking about will have their own controlled environment.

00:36:42Which means you won't need a space suit while inside.

00:36:46Should feel like stepping out of your space ride for a bit.

00:36:50Then of course, you'll need to put on your space suit.

00:36:53Alright.

00:36:55So we've got our homes and our rides sorted.

00:36:58But what about fuel?

00:37:00That's where the Moon throws us a lifeline.

00:37:02The Moon's lighter gravity means we don't need as much power to escape its pull.

00:37:07Plus, the Moon has ice.

00:37:10And that's super handy.

00:37:12We won't be able to convert this ice into rocket fuel.

00:37:15We'll need dedicated space gadgets to help gather this ice.

00:37:19One such tool is called Trident.

00:37:22It's like a drill, perfect for digging into the icy Moon surface.

00:37:26Additional robotic helpers would then turn this ice into fuel and deliver it to a space gas station.

00:37:33If this works, rockets on their way to Mars could stop by for a quick fuel top-up before continuing their journey.

00:37:43Put on your shades because Mercury is a hotspot.

00:37:47From the surface of this planet, the Sun looks three times bigger than it does from Earth.

00:37:52And the light is 11 times brighter.

00:37:55Mercury may spin slower than Earth, but it still knows how to have a good time.

00:38:00One day on this planet lasts a whopping 59 Earth days.

00:38:04But don't worry.

00:38:06A year on Mercury is only 88 Earth days long.

00:38:08So if you want to feel like a centenarian, just divide your age by naught, .25, or multiply it by 4.

00:38:15This way, you'll get your approximate Mercurian age. Easy peasy.

00:38:20And let's not forget about Mercury's funky orbit.

00:38:23For every two orbits around the Sun, it spins twice.

00:38:26That means each hemisphere gets a full year of daylight followed by a long night.

00:38:32Time zones would be a mess on this planet, so we'll just stick to GMT.

00:38:38Ugh, did anyone forget to take out the trash?

00:38:41Why does it smell of rotten eggs in here?

00:38:44Uh, sorry, it's because we're on Venus now, and these stinky clouds don't smell like roses.

00:38:50Any planet's day is basically just how long it takes for it to do a full spin on its axis.

00:38:55Well, Venus takes its sweet time with this, way slower than Earth, in fact.

00:39:01So a day on Venus lasts a whopping 243 Earth days, or almost 6,000 hours.

00:39:06Now here's where things get a bit tricky.

00:39:09Because Venus's day is so long, we actually use Earth's day as standard for keeping time on the planet.

00:39:14That means there's only one time zone for the whole planet.

00:39:17Seems convenient, huh?

00:39:19Venus's year is about 225 days.

00:39:22So if you were celebrating New Year's Eve on Earth in the year 2000, that would have been Venus's year 3251.

00:39:28So, to keep track of time on Venus, we can use the local year, made up of 225 Earth days,

00:39:35but every three years or so, there's an extra short year made up of only 224 days.

00:39:41Not that confusing.

00:39:43We have leap years on Earth, too.

00:39:45But it works a bit differently.

00:39:47We've made it to planet Earth.

00:39:50Woohoo! How many time zones do we have on this big blue ball?

00:39:53Give me a drumroll.

00:39:5524.

00:39:5624.

00:39:58And did you know that we can actually mess with time a little bit?

00:40:00Yep, in about 80 countries, mostly in Europe and North America, we have something called Daylight Saving Time.

00:40:07It's where we move our clocks forward an hour during the summer so we can soak up all that sweet, sweet sunshine.

00:40:13But beware, each country has its own rules about DST.

00:40:17So make sure you don't get caught snoozing when you're supposed to be working.

00:40:20And get this, some regions even have time zones that differ from UTC by half for quarter-hour increments.

00:40:28Can you imagine that the Moon is getting its own time zone?

00:40:33The European Space Agency announced on Monday that it's time for the Moon to have its own synchronized time zone.

00:40:40With more and more countries and private companies planning missions to our lunar neighbor,

00:40:45it's important that we all speak the same language when it comes to timekeeping.

00:40:51Right now, each mission carries Earth's coordinated universal time with it,

00:40:57which is fine when there are only a few missions happening at once.

00:41:01But with dozens of Moon missions planned over the next few years, things are going to get tricky.

00:41:06We need a system in place to make sure everyone's on the same page,

00:41:10or we'll end up with different spacecraft out of sync with each other, and nobody wants that kind of chaos in space.

00:41:16Precise timekeeping is super important for communication and navigation,

00:41:21so we need to figure out a way to make sure everyone's on the same page.

00:41:25The ESA hasn't figured out exactly what form this new lunar time zone will take, but they're working on it.

00:41:32Should there be a single organization responsible for keeping lunar time?

00:41:36Or should we let the Moon set its own time?

00:41:40And what about more granular time zones based on the Sun's position?

00:41:43These are all important questions that need to be answered.

00:41:48When it comes to a day on Mars, it's not too different from a day on Earth.

00:41:53We're talking 24 hours, 39 minutes, and 35 seconds.

00:41:57A Martian year is 1.8 Earth years, which means the Earth year 2000 happened in Martian year 1063.

00:42:05Almost forgot.

00:42:07The Martian year has 668 local days.

00:42:10Phew!

00:42:11We sorted out the Martian calendar, but Mars will need local time zones.

00:42:16Because of its elongated orbit, the difference between summer and winter hours will be significant.

00:42:21Daylight saving time will be a thing on Mars.

00:42:26A year on Jupiter lasts almost 12 Earth years.

00:42:30Yeah, that's like a lifetime in dog years.

00:42:33But don't worry, they've got 12 seasons to keep things interesting, each almost as long as an Earth year.

00:42:37But a day on Jupiter only lasts 9 hours and 55 minutes.

00:42:41Also, since Jupiter doesn't have a solid surface, the clouds move at different speeds,

00:42:46so two free-floating atmospheric stations could experience different days.

00:42:51Hey, if we lived on Jupiter, we'd be in bad need of some cool app tracking all those things.

00:42:57Anyway, if we ever terraform Jupiter's region, most of the population will still live on Jupiter's moons.

00:43:04Because the atmosphere is just too wild.

00:43:07And get this, the moon's revolution periods are connected,

00:43:11so we can use the same day counting system for all of them.

00:43:15On Io, we can have two standard Jovian days in one Earth day.

00:43:20How do we break that down?

00:43:22Well, we could have a minute of 53 seconds and an hour of 103 minutes.

00:43:27Or we could just stick with Earth's minute and hour and have a day that's 21 hours and 13 minutes long.

00:43:33How old are you?

00:43:34I'm 200 days old, and you?

00:43:36Sounds odd to you, Earth-dweller, but dudes on Saturn count their age in days.

00:43:41A year on Saturn is crazy long, like more than 29 Earth years.

00:43:45Kiddos would only get a fraction of a year, while the oldest folks might get a whopping three years.

00:43:50So to keep track of time on Saturn, we could divide up a Saturnian year into 29 or 30 seasons.

00:43:57Oh, and fun fact, Saturn doesn't even have a solid surface,

00:44:01just rotating clouds that spin at different speeds.

00:44:05But we could still set up some cool research stations or helium extraction balloons to float around up there.

00:44:11One Uranian year lasts a whopping 84 Earth years.

00:44:16So to make things easier, we'll stick to using Earth years for our calculations,

00:44:21and natural Uranian years can be used for special occasions, like reaching one Uranian year old.

00:44:27As Uranus doesn't have a solid surface, the rotation period is all over the place.

00:44:32Only science missions and helium mining companies are brave enough to venture into the atmosphere.

00:44:38And get this, each moon has its own day and date system. Pretty confusing.

00:44:44Most people won't ever celebrate one Neptunian year old.

00:44:48One year on Neptune is like that's way too long for us humans to stick around.

00:44:52But don't worry, we'll still bust out the confetti and party hats for special occasions,

00:44:57like when it's been two whole years since the first spaceship hit up Neptune.

00:45:02As for the rest of the time, we'll just use Earth years for all our business needs.

00:45:07Pluto takes a whopping 240 Earth years to orbit the Sun,

00:45:12which is way too long to use as a year in our everyday lives.

00:45:15A day on Pluto is almost like a week on Earth.

00:45:17So, to keep track of time, we're going to divide that into six standard Plutonian days,

00:45:23three of light and three of dark.

00:45:26That means a standard day on Pluto will last slightly more than one Earth day.

00:45:30Now because Pluto's axis is super tilted, using time zones would be pointless.

00:45:35So we'll just use one time zone for the whole system. Easy peasy.

00:45:40As for the standard Plutonian year, it'll be almost the same as the Earth year, about 343 days.

00:45:47But once in ten years, we'll throw in an extra day just for kicks.

00:45:51That's all for now. See you on Pluto.

00:45:54NASA has some incredible plans for the Moon.

00:45:57For example, their next ambitious lunar program, Artemis II.

00:46:01They've set their sights on landing astronauts, including the first woman and the next man, on the Moon by 2024.

00:46:08Artemis is all about building a sustainable presence on the Moon.

00:46:11They're planning to establish a lunar gateway, a sort of space station in lunar orbit,

00:46:15which will serve as a jumping-off point for lunar landings.

00:46:19And let's not forget about the cool lunar landers.

00:46:22Scientists are developing the mighty Space Launch System rocket,

00:46:25which will launch the Orion spacecraft carrying astronauts towards the Moon.

00:46:28Then there's the human landing system, a snazzy lunar lander that will gently touch down on the Moon's surface,

00:46:34allowing astronauts to explore and conduct amazing scientific experiments.

00:46:39And NASA isn't going alone this time.

00:46:41They're teaming up with international partners, like the European Space Agency, to make this lunar dream a reality.

00:46:48But all these wonderful dreams might be ruined by something that seems super small and insignificant at first.

00:46:55Picture this. No atmosphere, no air to breathe.

00:46:59And suddenly, a mysterious haze and radiant beams of light appear at sunrise and sunset.

00:47:05It's as if the Moon is putting on a celestial show.

00:47:08But there is a twist to this beauty.

00:47:11On the Apollo 17 mission in 1972,

00:47:14this beautiful sight made one of the NASA astronauts, Harrison Schmitt, sneeze and made his eyes water.

00:47:21He called it Lunar Hay Fever.

00:47:24This mysterious fever affected all 12 Moonwalkers.

00:47:27From sneezing fits to stuffy noses, those astronauts experienced symptoms as if they caught a cold.

00:47:33It took days for their reactions to fade away.

00:47:36This event led to a discovery about lunar dust and its darker side.

00:47:41When scientists found out about these rays, they rolled up their sleeves and delved into their origins.

00:47:47And here's what they discovered.

00:47:49Those radiant bands of light were actually caused by sunlight sneaking through layers of teeny tiny lunar dust.

00:47:55The dust was composed of small particles and sharp glass shards, and was lurking everywhere.

00:48:01And it turned out that this lunar dust was a sneaky villain.

00:48:05It brought a whole host of problems.

00:48:07Astronauts who found themselves with impaired vision were just the beginning.

00:48:11The troublemaker went even further, damaging precious machinery and causing electronic malfunctions.

00:48:17It even had the audacity to corrode components and smelled like burnt gunpowder inside the spacecraft.

00:48:24Yikes!

00:48:26It clings to everything, coating surfaces like a mischievous blanket.

00:48:29It can clog up equipment, get into delicate machinery, and even mess with astronauts' spacesuits.

00:48:35In 1972, things got really hairy again.

00:48:38The Apollo 17 astronauts faced a nightmare.

00:48:42After just 22 hours of gallivanting on the lunar surface, their spacesuits suffered irreparable damage.

00:48:48Yes, you heard that right. Irreparable.

00:48:51The dust diminished astronauts' mobility, making it harder for them to move around and perform their moonwalks with grace.

00:48:57And no matter how hard they tried to clean it off, it clung on for dear life, leaving the spacesuits in a sorry state.

00:49:04So, as you can see, it poses some serious challenges for future moon missions.

00:49:09But our intrepid scientists aren't giving up.

00:49:12To solve this problem, they have to understand how lunar dust forms and why it's so darn clingy.

00:49:17They found out that it all begins with meteorite impacts.

00:49:21When these space rocks crash into the moon, they generate a fine dust that fills the air.

00:49:26Sometimes these impacts even cause minerals to melt, forming sharp glass shards that mix with the dust.

00:49:32Talk about a moon makeover.

00:49:34The dust is also filled with silicate, a material commonly found on volcanic planets.

00:49:40Silicate inhalation can cause serious lung problems for Earth's miners, so you can imagine the trouble it can cause on the moon.

00:49:47A recent study found that even a scoop of replica moon dust was toxic enough to destroy up to 90% of lung and brain cells exposed to it.

00:49:54But it gets worse.

00:49:56The low gravity on the moon allows those tiny particles to float around for much longer, penetrating deeper into the lungs.

00:50:02Imagine breathing particles 50 times smaller than a human hair for months.

00:50:07That's a recipe for trouble.

00:50:09And you see, on the moon's surface, things are a bit different than here.

00:50:14There are no rainstorms or strong gusts of wind to blow this dust away.

00:50:18There is also no atmosphere to protect the surface.

00:50:21So without the natural forces of wind and water erosion like we have on Earth, these dry particles stick around persistently.

00:50:28And to make matters more electrifying, the moon is constantly showered by radiation from the sun.

00:50:34This exposure gives the dust an electric charge.

00:50:37The solar winds create positively and negatively charged particles.

00:50:41The particles then buzz around, repelling each other and giving rise to those radiant bands of light that the Apollo 8 astronauts witnessed.

00:50:49It's like a disco party on the moon.

00:50:52ESA, the European Space Agency, has gathered a team of experts to study the lunar dust.

00:50:58They're working with simulated moon dust mined from a volcanic region in Germany to understand its behavior and effects.

00:51:05Engineers also need to find a way to protect future astronauts and equipment.

00:51:09Engineers and NASA want to create spacesuits that can survive not one, not ten, but a whopping 100 extravehicular activities on the lunar surface.

00:51:18That's like spending 800 hours out there, exploring and having a blast.

00:51:23Besides that, NASA initiated the Breakthrough Innovative and Game-Changing Idea Challenge in 2021.

00:51:30It was open to clever university students from all over the world.

00:51:34These young minds put their thinking caps on and unleashed a wave of innovative solutions.

00:51:39For example, they proposed using special fibers that conduct electricity, inspired by fluffy chinchilla hair.

00:51:45Just like how chinchillas stay dust free, these fibers would help keep the lunar dust at bay.

00:51:51A furry friend lending a helping paw, isn't that adorable?

00:51:55Another bright idea involved an electrically charged brush activated by UV radiation.

00:52:01It's like a magical wand that zaps away the dust with a flick.

00:52:05Abracadabra, lunar dust be gone.

00:52:08And let's not forget the fabric inspired by clever insects.

00:52:10These insects have pollen collecting structures that repel unwanted dust.

00:52:14So our ingenious students thought, why not mimic that?

00:52:18They designed a fabric with similar properties, creating a shield against the sneaky lunar particles.

00:52:23What's remarkable about these ideas is that they all use the power of charge to fight the dust.

00:52:29They cleverly repel it from the spacesuits, keeping them clean and protected.

00:52:34And even though all these ideas sound pretty great,

00:52:36scientists in NASA unleashed another, even better solution.

00:52:40Carbon nanotubes.

00:52:42It's a great way to revolutionize spacesuit fabric.

00:52:45What makes these carbon nanotubes so special?

00:52:48Well, they possess some amazing superpowers.

00:52:52First off, they're superconductive, meaning they can carry electricity like nobody's business.

00:52:57It's like having a lightning bolt trapped inside a microscopic tube.

00:53:00Not only that, but these carbon nanotubes are tougher than the toughest meteors.

00:53:04They have the strength to withstand the harsh lunar environment,

00:53:08where even a speck of dust can cause trouble.

00:53:11Imagine having a suit made of a material that's stronger than Superman's cape.

00:53:15So, NASA's scientists decided to weave these extraordinary carbon nanotubes into the spacesuit fabric.

00:53:22The electrodes were carefully integrated into the outer layer of the fabric,

00:53:26making it a force to be reckoned with.

00:53:27But how do they banish the lunar dust?

00:53:30Well, here comes electrifying science again.

00:53:33When activated by a special alternating current,

00:53:36the electrodes create powerful electric fields.

00:53:39These fields work like magnets,

00:53:41repelling both charged and uncharged dust particles away from the spacesuit.

00:53:46Picture this like a dance party,

00:53:48where the dust particles are the uninvited guests,

00:53:51and the electric fields are the bouncers,

00:53:53swiftly accelerating the electric field.

00:53:55Thanks to this technology,

00:53:57lunar dust doesn't stand a chance against our astronauts.

00:54:01Also on the bright side,

00:54:03the lunar soil can be used to make bricks for shelters.

00:54:06It can also help extract oxygen for astronauts to survive on the moon for long periods of time.

00:54:11When life gives you lemons,

00:54:13make a lemonade, right?

00:54:15So, let's cheer on our NASA dream team as they embark on this epic lunar quest.

00:54:20Let's hope that they succeed in their findings,

00:54:22and the next movie will be about them.

00:54:23Let's hope that they succeed in their findings,

00:54:25and the next moon mission won't be a big problem.

00:54:27Stay tuned!

00:54:29Consider now Enceladus, Saturn's icy moon,

00:54:33one of the most promising places to look for life outside Earth.

00:54:37Scientists have just detected the last one of the six necessary ingredients for its formation,

00:54:42phosphorus.

00:54:44This rarest element has been discovered in an ocean on Enceladus.

00:54:48This rare element helps make the soil fertile on Earth.

00:54:51But the concentration of this mineral in the hidden seas on the distant moon

00:54:55might be from 100 to 1,000 times greater than in the oceans of our home planet.

00:55:01It might be because Enceladus' ocean is rich in carbonates,

00:55:05just like soda water,

00:55:07and this soda water is likely to dissolve the phosphates in the moon's rocks.

00:55:11The new discovery also suggests that on other icy moons of Saturn,

00:55:16like Titan, the waters may be loaded with phosphorus too.

00:55:20Why are scientists so excited about this mineral?

00:55:23Well, phosphates, which are compounds that contain phosphorus,

00:55:27are crucial components of life on Earth.

00:55:30DNA, RNA, and cell membranes contain them.

00:55:34But among those six elements required for life,

00:55:37which are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur,

00:55:42phosphorus is the least common.

00:55:44In 2004, the Cassini space probe entered the dust from the second outermost ring of Saturn,

00:55:50called the E ring.

00:55:52It's made up of ice grains Enceladus ejects.

00:55:55And while studying these ice grains examined by Cassini's cosmic dust analyzer,

00:56:00researchers have detected phosphorus.

00:56:03Enceladus is the sixth-largest moon of Saturn.

00:56:07It's not really large, only 314 miles across.

00:56:10This makes the space body small enough to fit inside Arizona.

00:56:15Hmm, we should try that sometime.

00:56:18Interestingly, when the Cassini space probe first arrived at Saturn,

00:56:22astronomers thought that Enceladus was going to be a frozen ball of ice.

00:56:26But then, surprise surprise,

00:56:28they spotted plumes of icy particles and water vapor erupting from geysers on the moon's surface.

00:56:34It became clear that there was a global ocean

00:56:37between the moon's rocky core and its icy shell.

00:56:41The same researchers previously discovered that Saturn's moon

00:56:44might be home to complex organic molecules, too.

00:56:48Before, scientists thought phosphates could be trapped within the rocky cores of Enceladus and similar worlds.

00:56:54That's why the newest works,

00:56:56which hint that phosphates might also be abundant in the ocean, came as a surprise.

00:57:01Researchers examined 305 ice grains from Saturn's E ring,

00:57:06and found out that 9 of them contained phosphates.

00:57:09And these results were clear and unmistakable.

00:57:12And it's very important because some time ago,

00:57:15phosphine, a compound of hydrogen and phosphorus,

00:57:18was believed to exist in the clouds of Venus.

00:57:21But no one has managed to find any evidence to support this theory.

00:57:25On Enceladus, there's no controversy, and phosphates do exist there.

00:57:31Astronomers consider Europa one of the most promising places in the solar system

00:57:36for new life forms.

00:57:38All because this moon has a huge saltwater ocean with a depth of 40 to 100 miles.

00:57:44Yes, it is hidden under a layer of ice that is estimated to be from 10 to 20 miles thick.

00:57:50But it is still potentially habitable.

00:57:53Astronomers claim that plumes of water erupt from cracks in the ice shell

00:57:58and release the contents of the moon's ocean into space.

00:58:01Of course, it's going to be challenging for any life-seeking mission

00:58:06to access such a deep environment.

00:58:08On the bright side, as we are,

00:58:10scientists already have some evidence that there are way shallower pools

00:58:15that probably lie much closer to the surface of the moon.

00:58:18They might be located even less than one mile under the ice.

00:58:22And there are two great things about this news.

00:58:25First of all, it boosts the odds of life existing on Europa.

00:58:29And secondly, if it's true, it can make it easier for future missions

00:58:33to find these life forms, if there are any.

00:58:36Then we've got Titan, Saturn's largest moon.

00:58:39It's smaller and has lighter gravity than Earth,

00:58:42but it still reminds us of our planet.

00:58:45Like on Earth, nitrogen dominates its atmosphere.

00:58:48Titan is the only other world in our solar system with lakes and rivers.

00:58:52These water bodies are made of hydrocarbons, methane, and ethane.

00:58:57There's also a subsurface ocean of water, but it's located very deep down,

00:59:01and no one has figured out yet if this ocean makes contact with anything under the surface.

00:59:07If it does, it could provide fuel for life after mixing with complex chemistry on the surface.

00:59:13But Enceladus and the other icy moons aren't the only place in the solar system

00:59:18that might host or once hosted life.

00:59:21In 2003, Mars Express, a spacecraft launched by the European Space Agency,

00:59:27discovered methane in the atmosphere of Mars.

00:59:29On our planet, the biggest part of this gas in the atmosphere is produced by living creatures,

00:59:35for example, by cattle digesting food and emitting, you know, gas.

00:59:40However, scientists think that methane was stable in the Martian atmosphere for about 300 years.

00:59:46And then, in 2006, the methane almost entirely vanished from the Red Planet.

00:59:52And it happened 600 times faster than the researchers' model accounted for.

00:59:57The question? What or who generated the gas, and where did it go?

01:00:03Another Martian mystery is microbes that might be sleeping beneath the surface of Mars.

01:00:09There, they might have been protected from the harsh radiation coming from space for millions of years.

01:00:15Scientists simulated the conditions on Mars in a lab to check if it could possibly be true.

01:00:20And they were amazed to find out that bacteria could easily survive in such conditions for 280 million years.

01:00:28Ooh, that's a long shelf life!

01:00:31This means that if life existed on Mars,

01:00:34we could find the evidence in the planet's subsurface by drilling into the Martian soil.

01:00:39Right now, there is no flowing water on Mars, and cells or spores would simply dry out.

01:00:45Plus, the frozen temperature is similar to that of dry ice.

01:00:48In other words, it's deeply frozen. Let it go.

01:00:53And still, there could be six types of bacteria and fungi living underground on the Red Planet.

01:00:59The most likely of them is nicknamed Conan the Bacterium due to its tough nature.

01:01:05Well, I guess time will show.

01:01:07Anyway, if we don't find life outside Earth and our solar system,

01:01:11we could probably look for it on exoplanets, which is what planets outside our star system are called.

01:01:18Some of them look very promising.

01:01:21The closest to Earth exoplanet is Proxima Centauri b.

01:01:25It's a mere 4.2 light-years away from Earth.

01:01:28Recently, astronomers have found out that this world might resemble Earth even more than they previously thought.

01:01:35It's just 17% more massive than our home planet.

01:01:39It orbits a star that is dimmer and less massive than the Sun.

01:01:43Proxima Centauri b is in the middle of the star's habitable zone.

01:01:46This means that the chances of liquid water and life might exist on the planet.

01:01:52It looks like the exoplanet is tidally locked with its parent star.

01:01:56One of its sides faces the star at all times, and the other is always in the darkness.

01:02:02Scientists haven't figured out yet whether the planet has an atmosphere,

01:02:06is traveling too close to its star, and completes one orbit within 11 Earth days.

01:02:12The radiation from the star might be pulling the planet's air away.

01:02:16If that's the case, Proxima Centauri b isn't likely to have liquid water on its surface.

01:02:22Gliese 832 c is 16.2 light-years away from Earth.

01:02:28In the cosmic scheme of things, it's a stone's throw away.

01:02:32This exoplanet is 5 times as massive as Earth and travels much closer to its parent star.

01:02:38That's why a year on this planet lasts a mere 36 days.

01:02:41But since this star is a red dwarf, much cooler and dimmer than the Sun,

01:02:46Gliese 832 c gets as much light and heat as our planet.

01:02:51At the same time, it's still unclear if it's similar to Earth.

01:02:56The planet probably has a much thicker atmosphere that creates a runaway greenhouse effect.

01:03:01This phenomenon occurs when a planet absorbs more heat from its host star

01:03:06than it can release back into space.

01:03:08This means that Gliese 832 c is more likely to resemble scorching hot Venus

01:03:14rather than the relatively cool Earth.

01:03:16Hey, I'm cool with that.

01:03:21Okay, I officially give up on the hope that the Moon is made of cheese after all.

01:03:26Wow, not even Gouda.

01:03:28The shiny lunar ball, or a curved banana, or half of a coin depending on what phase it's in,

01:03:34has different layers inside, just like Earth.

01:03:36One of these layers is called the inner core.

01:03:39About 20 years ago, scientists were observing how the Moon rotates.

01:03:44Using that data, they concluded that it had a fluid outer core.

01:03:48But the inner core was hard to study,

01:03:50so they didn't know if it was solid like a rock or molten like a hot liquid.

01:03:55But things are clearer now.

01:03:57Astronomers have collected data from different missions, including the Apollo missions,

01:04:01where astronauts went to the Moon and gathered information themselves.

01:04:05Plus, they've used a special technique called seismic data.

01:04:09This method is all about studying how sound waves move through things.

01:04:13Take earthquakes on our planet as an example.

01:04:16When an earthquake happens, it creates waves that travel through the ground.

01:04:20Scientists can detect and analyze these waves to learn more about Earth's interior.

01:04:25The same idea can apply to other objects in our solar system,

01:04:28or planets, or, in this case, the Moon.

01:04:32When quakes or moonquakes happen, they generate sound waves.

01:04:36And by carefully listening to and studying these waves,

01:04:40scientists can create a detailed map of what's inside the object.

01:04:44They can figure out things like different layers, what they're made of, and how they're arranged.

01:04:49To check the Moon's deep interior, scientists also use something called laser ranging.

01:04:54This method measures the distance between the surface of the Earth and the Moon very precisely.

01:05:00And ta-da!

01:05:02Our natural satellite's inner core is a dense, solid ball made of iron, just like Earth's.

01:05:08It's about 310 miles wide, which is nearly 15% the size of the entire Moon.

01:05:14Researchers also have stumbled upon evidence that supports the theory

01:05:18that the layer between the Moon's surface and its core, called the mantle,

01:05:21has been moving around as the Moon evolved over time.

01:05:26This movement is something we call lunar mantle overturn,

01:05:30and it could explain why we find elements rich in iron on the lunar surface.

01:05:35Mantle material ends up being carried upward,

01:05:38and the volcanic rock remains in the Moon's crust.

01:05:42Some of the materials in this rock were too dense, like me,

01:05:45so they just sank back through the lighter crust material all the way to the core-mantle boundary.

01:05:52It's like a cycle where the Moon's mantle material goes up during volcanic activity,

01:05:58carries iron-rich elements to the surface, and then sinks back down.

01:06:02There's another mystery scientists have been trying to solve.

01:06:06What caused the Moon's magnetic field to weaken and nearly disappear over time?

01:06:10It seems that now that we know about the iron core and the global mantle overturn,

01:06:16we might get some more answers about the Moon's magnetic field.

01:06:19Knowing what the inner core is like can help us better understand the Moon's history

01:06:24as well as the history of our entire solar system.

01:06:27One of the theories that's widely accepted about the origin of the Moon

01:06:32says there was a massive collision between Earth in its early stages

01:06:36and another mysterious object in our solar system.

01:06:38It's called the Large Impact Theory, and this collision was so strong

01:06:43it ripped off a big chunk of the primitive molten Earth.

01:06:47I mean, not so big compared to what's left.

01:06:50If you put a US nickel next to a green pea,

01:06:53you get a good idea of how big our planet is compared to the Moon.

01:06:56This chunk was sent into orbit around our planet,

01:07:00and this might've happened about 95 million years after our solar system formed.

01:07:05The object that collided with Earth could've been about 10% the mass of our home planet

01:07:11and roughly the size of Mars.

01:07:13Well, it makes sense – Earth and the Moon do have similar compositions, after all.

01:07:18Of course, there are other ideas about how the Moon formed.

01:07:22One says that the gravitational force of our planet captured it.

01:07:27This means that the Moon was just an object innocently passing by

01:07:31when suddenly it got attracted and pulled into Earth's orbit.

01:07:35There's even a hypothesis that Earth stole the Moon from Venus.

01:07:39In that case, the Moon shouldn't complain.

01:07:42I guess the view is way better here.

01:07:44So yeah, the Moon and Earth are similar when it comes to rocks and some minerals.

01:07:49But the Moon doesn't have the same atmosphere as our planet.

01:07:52Its atmosphere is thin and consists of some weird gases that include potassium and sodium,

01:07:57which is not something you can find in the atmosphere of Mars, Venus, or Earth.

01:08:02And the rocks on the Moon don't contain water.

01:08:05But that doesn't mean there's no water at all up there.

01:08:08A long time ago, in the 17th century, astronomers saw large dark spots on the Moon's surface.

01:08:15One of these astronomers thought these spots looked like oceans,

01:08:19and he called them maria, which means seas in Latin.

01:08:22Other astronomers also made maps of the Moon,

01:08:24and they used the term maria to describe these dark spots.

01:08:28For example, Mare Tranquillitatis translates to Sea of Tranquility,

01:08:33where Apollo 11 made its touchdown.

01:08:36But it seems those dark spots are not actually oceans.

01:08:40They are plains made of hardened lava that erupted long ago.

01:08:44These volcanic eruptions left behind smooth, flat areas called basalt plains.

01:08:49In the late 1800s, one sky watcher studied the Moon and found it didn't have an atmosphere.

01:08:56Without an atmosphere, there are no clouds and no air to keep water from evaporating.

01:09:01So scientists thought that any water on the Moon would just disappear right away.

01:09:06They believed the Moon was totally dry.

01:09:09But then, in 1961, one physicist had a different idea.

01:09:13He pointed out there could be water on the Moon in special areas called permanently shadowed regions.

01:09:19These are spots on the Moon where the Sun doesn't shine, so they stay dark all the time.

01:09:25Water ice could exist in these dark areas because they're extremely cold and the ice wouldn't evaporate.

01:09:32But when astronauts from the Apollo missions went to the Moon,

01:09:36they brought back soil samples, and scientists found no signs of water in them.

01:09:40So everyone went back to thinking that the Moon was completely dry.

01:09:44In the 90s, NASA focused on these shadowed craters and found high concentrations of hydrogen,

01:09:51which meant there could be ice at the Moon's poles.

01:09:54They still weren't certain, so they kept digging and, after a while,

01:09:58found hydrogen trapped inside tiny beads of volcanic glass.

01:10:02Since there are no active volcanoes on the Moon today,

01:10:05which means water probably was present on the Moon when these volcanoes erupted long ago.

01:10:10Plus, there could be way more water back in the early days of our Moon.

01:10:15In 2020, NASA's SOFIA mission showed us what we'd been looking for for a really long time.

01:10:21There is water on the Moon, after all.

01:10:24It turns out the water is hidden within the grains of lunar dust

01:10:28or sticking to the surface in the sunlit areas of the Moon.

01:10:31So, there are no oceans like we have on Earth, but at least there's something.

01:10:36The question remains, how did water even get there?

01:10:40It seems the Moon had a chaotic history back at the time when it was forming,

01:10:45as probably most of the planets and moons in our Solar System.

01:10:49So, there is some evidence that water came there from comets hitting its surface back in the old days.

01:10:55Or maybe even keeps on coming back.

01:10:57We're talking about a chaotic situation where icy micrometeorites collide with the Moon's surface

01:11:03and dust then makes an even bigger mess when interacting with the solar wind.

01:11:08But we're waiting to find out more about this.

01:11:11Because, as we all know, when you mention water, you also inevitably talk about life.

01:11:18That's why we want to know more.

01:11:20For instance, about all that ice hidden in polar craters on the Moon.

01:11:24Maybe it can teach us more about how life developed on Earth.

01:11:28Maybe comets brought all the necessary elements here.

01:11:31Then, what if there are some of those elements stuck in the ice on the Moon too?

01:11:36Hmm…

01:11:51Ah, well-deserved vacay, finally.

01:11:54This time you're off to see something new.

01:11:56It's an ocean on one of the Uranus' moons.

01:11:59Alright, just kidding.

01:12:01This destination is not a vacation spot yet.

01:12:03But, yeah, there are definitely some impressive oceans out there.

01:12:07Hey, don't say you thought oceans can only be found on Earth.

01:12:11But before diving into Uranus' Moon's oceans, let's talk about Uranus itself first.

01:12:16The seventh planet from the Sun, and the coolest cat in the solar system.

01:12:21It's got 27 moons, and four of them might technically have oceans.

01:12:25That's more than most people have friends.

01:12:28All these moons are like Uranus' mini-me's.

01:12:30They tilt at the same crazy angle as their parent planet, 98 degrees to be exact.

01:12:35And Uranus is so unique that it orbits the Sun on its side.

01:12:39That means its equator is almost at a right angle to its orbit.

01:12:42Talk about rebellious.

01:12:44But why is Uranus like this?

01:12:46Well, some astronomers reckon it's because it got knocked on its side by a massive collision with another planet.

01:12:52And that impact might have actually created Uranus' moons.

01:12:55Fun fact, those moons have pretty particular names.

01:12:58Instead of mythical figures, most of them are named after Shakespearean characters.

01:13:02I mean, who needs Zeus when you've got Juliet and Desdemona?

01:13:06Discovering these moons isn't easy.

01:13:08They're super dark and located billions of miles away from the Sun.

01:13:11It's like trying to find a needle in a haystack.

01:13:14Except the needle is smaller than your pinky finger.

01:13:17These 27 satellites are divided into three groups.

01:13:2013 inner moons, 5 major moons, and 9 irregular moons.

01:13:25The irregular ones are rebels with retrograde orbits,

01:13:28while the others are prograde and go with the flow of Uranus.

01:13:32The big boys are Miranda, Ariel, Umbriel, Titania, and Oberon.

01:13:37And they're all in Uranus' equatorial plane.

01:13:39They're all in Uranus' equatorial plane and are big enough to be round.

01:13:43They've got craters and canyons and cliffs.

01:13:46Oh my.

01:13:48These moons also formed from a giant impact that tilted Uranus on its axis.

01:13:51That's why they're all tilted too.

01:13:53And because of that tilt, they have crazy seasonal cycles just like Uranus itself.

01:13:58But we haven't found all of Uranus' moons yet.

01:14:01The little irregular ones are sneaky and hard to detect.

01:14:04So who knows how many more there could be.

01:14:06But let's talk about the really cool stuff.

01:14:09What these moons are made of.

01:14:11We're not entirely sure, but we think they're made of rock and ice.

01:14:14Miranda is the most icy one, while the inner moons are probably just dusty.

01:14:19And the ones beyond Oberon's orbit?

01:14:21They're likely captured asteroids that could be rocky.

01:14:23Or icy.

01:14:25Or who knows what.

01:14:27But here's what really sets Uranus' moons apart.

01:14:29They're all tilted together with Uranus.

01:14:31That's wild.

01:14:33Exploring these moons could teach us so much about how ocean worlds form.

01:14:36And stay active.

01:14:37Titania is the biggest moon of Uranus.

01:14:40But it's still less than half the size of Earth's moon with a diameter of about 1,000 miles.

01:14:45It's also the 8th heaviest moon in the whole solar system.

01:14:48They named it after the Fairy Queen in A Midsummer Night's Dream.

01:14:51Titania's color is grey, and it has some shiny patches that scientists think are frost.

01:14:56It's made up of a mix of ice and rock, just like all the other moons close to Uranus.

01:15:01Oberon is the next biggest moon of Uranus, named after the Fairy King in Shakespeare's play.

01:15:07It's almost the same size as Titania, and also has a half-ice-slash-half-rock composition.

01:15:12But Oberon's surface is way more cratered than the other Uranian moons.

01:15:16Umbriel and Ariel are the 3rd and 4th largest moons of Uranus, with diameters of 726 miles and 718 miles respectively.

01:15:26Umbriel is named after a bad spirit in an old poem, and it's the darkest of all Uranus' big moons.

01:15:33It only reflects 16% of the light that hits it.

01:15:35Scientists don't know why it's so dark, but they think a bright ring around a crater might be caused by frost deposits.

01:15:42Ariel is the brightest of all Uranus' big moons, and it reflects over a third of the light that hits it.

01:15:48It's named after characters in both Pope's poem and Shakespeare's play.

01:15:52Ariel looks like the youngest moon, because it only has a few small craters from recent collisions.

01:15:58Miranda is the smallest of all these big moons with a diameter of about 292 miles.

01:16:03NASA says it looks like it's made up of parts from different bodies, like a Frankenstein's monster.

01:16:09Miranda has three big features called coronae that are unique to it.

01:16:14They're lightly cratered with ridges and valleys, and they're separated from older and more heavily cratered parts of Miranda by sharp boundaries.

01:16:22It also has giant canyons that are up to 12 times deeper than the Grand Canyon.

01:16:27Scientists don't know why Miranda has such different features.

01:16:30But one theory is that it got smashed apart by a huge collision, and then put back together all wonky.

01:16:37All these big Uranian moons are stuck facing Uranus all the time, just like Earth's moon.

01:16:43Uranus has got some seriously dope features, but the ring system is where it's at.

01:16:48And get this, the ice giant's moons actually have a hand in shaping those rings.

01:16:52Uranus has 13 inner moons, and 13 faint rings, and they're all connected like wire.

01:16:57And 13 faint rings, and they're all connected like one big cosmic family.

01:17:02Cordelia and Ophelia are like the guardians of the outermost ring, Epsilon.

01:17:07These two shepherd moons keep all the particles together, with Cordelia being the closest to Uranus' surface.

01:17:13But here's the kicker. There are at least 8 other tiny satellites hanging around in that area, making things super crowded.

01:17:20NASA is still scratching their heads trying to figure out how they don't all crash into each other.

01:17:25The inner moons are half ice and half rock, but we don't know much about the outer ones.

01:17:30NASA thinks they might just be asteroids that got caught up in Uranus' gravitational pull.

01:17:35Either way, Uranus and its moon squad are definitely out of this world.

01:17:39Apparently, Uranus' moons might have salty oceans hiding under their frozen surfaces,

01:17:45and the farthest ones from Uranus, Titania, and Oberon could have oceans that are 30 miles deep.

01:17:50That's deeper than the Mariana Trench, 7 miles.

01:17:54But even Ariel and Umbriel might have oceans around 19 miles deep.

01:17:58NASA used some fancy computer modeling and revisited data from their Voyager 2 spacecraft,

01:18:04launched way back in 1977, to figure out the makeup and structure of these moons.

01:18:09They found that Titania is huge enough to keep its internal heat and prevent its ocean from freezing.

01:18:15But get this. The other moons might have a chance at having warm oceans too.

01:18:20The researchers discovered potential sources of heat in the moons' rocky mantles

01:18:25that could release hot liquid and keep the oceans warm.

01:18:28And guess what? The oceans might even be warm enough to theoretically support life.

01:18:33The study also found that chlorides and ammonia are likely abundant in the oceans of these moons.

01:18:38Ammonia acts as antifreeze, and salts in the water could also help maintain the oceans' temperature.

01:18:44Now you might be thinking, how can these icy moons have liquid water?

01:18:48Well, turns out their internal heat and some chemicals could make it happen.

01:18:53For example, a study revealed that chlorides and ammonia are likely abundant in the oceans of these moons.

01:18:59Ammonia acts as antifreeze, and salts in the water could also help maintain the oceans' temperature.

01:19:04And if these moons really do have oceans, that means there could be other ocean worlds in our solar system and beyond.

01:19:10But don't get too excited. These oceans are pretty salty.

01:19:14About 150 grams of salt for every liter of water.

01:19:16That may not be saltier than Utah's Great Salt Lake, but still.

01:19:21As for Uranus' fifth biggest moon, Miranda, welp.

01:19:24It might have had an ocean at some point, but it probably froze over pretty quickly.

01:19:29Poor little guy.

01:19:31Anyway, NASA is thinking about sending a mission to Uranus to learn more about these icy giants and their moons.

01:19:37They're calling it the Uranus Orbiter and Probe UOP.

01:19:42Sounds like a party to me.

01:19:43So yeah, technically there might be not four but even five oceans.

01:19:47But there's still much to learn and explore.

01:19:50Ah, what a nice cosmic family.

01:19:53Meet Mars. I bet you've met him before.

01:19:56These two little guys are Phobos and Deimos, Mars' small moons.

01:20:01But it seems like Mars isn't treating the little ones the right way.

01:20:05Phobos and Deimos are believed to be captured asteroids.

01:20:09However, Phobos is gradually moving closer to Mars due to gravity.

01:20:14And it is predicted that it will eventually be destroyed by the planet's gravity within the next 35 million years.

01:20:21I won't be around then.

01:20:23So, I imagine, this will result in a ring of debris around Mars, similar to Saturn's rings.

01:20:29However, this process is a natural phenomenon and not an act of destruction by Mars.

01:20:34Apparently, Phobos is getting ripped apart by the crazy gravitational forces of the red planet.

01:20:40But wait, there's more!

01:20:42Phobos has these crazy parallel grooves all over its surface.

01:20:46We used to think that they were from an asteroid crash.

01:20:49But now scientists think they're actually from Mars' intense gravity pulling the moon apart.

01:20:55Talk about a rough ride!

01:20:57Scientists have this wild idea that when a little guy like Phobos gets too close to a big guy like Mars,

01:21:05it starts to stretch out towards it.

01:21:07They call it the tidal force.

01:21:09Phobos is predicted to get stretched out so much that it'll actually break apart.

01:21:15Crazy, right?

01:21:17And the debris from the moon will form a tiny ring around Mars, just like Saturn's rings.

01:21:21Now, some people thought that Phobos' tiger stripes were caused by tidal forces before.

01:21:27But that theory got shut down because the moon is just too darn fluffy.

01:21:32But now, these genius researchers ran some computer simulations

01:21:36and found out that maybe there's a hard shell underneath all that fluff that could create grooves on the surface.

01:21:43But don't worry.

01:21:45At the rate Phobos is going, it's gonna crash into Mars in about 40 million years.

01:21:48But if tidal forces are already tearing it apart, it might not even last that long.

01:21:55However, we'll still have the chance to learn more about Phobos.

01:21:59NASA just picked 10 rockstar researchers from all over the U.S.

01:22:03to join the science working team for JAXA's Martian Moons Exploration, or just MMX, mission.

01:22:10As NASA supported participating scientists, they'll be helping JAXA explore the two Martian moons, Phobos and Deimos.

01:22:16And get this, they're even planning to land on Phobos and grab a surface sample.

01:22:23The mission is set to launch in 2024, and we'll get our hands on that sample in 2029.

01:22:29Seven of the lucky researchers will be using the MMX flight instruments to conduct their research.

01:22:35Phobos is a real oddball.

01:22:37It's only 17 miles wide and orbits Mars at a distance of 3,728 miles, to be precise.

01:22:45Now that's way closer than Earth's moon, which takes a whole 27 days to orbit us.

01:22:51But Phobos is in a death spiral toward Mars and is slowly falling towards the planet's surface at a rate of 6 feet every 100 years.

01:23:00But there must be a reason why Mars is acting that nastily, right?

01:23:05What if it's all just because of plain vengeance?

01:23:08Well, okay, picture this.

01:23:10Mars is minding its own business, being all hot and watery like a young Earth.

01:23:15It's got a sweet magnetic field that's protecting it from cosmic radiation and keeping its atmosphere nice and thick.

01:23:22Hey, life is good!

01:23:24But then, at least 20 asteroids, each the size of a small country, come crashing down on Mars like a giant game of cosmic whack-a-mole.

01:23:33One of them even leaves a crater that's almost 2,000 miles wide.

01:23:37Now imagine how Mars must feel with two asteroids being its moons after what other asteroids did to the Red Planet.

01:23:45All these impacts are like a massive punch to Mars' gut, and its already weak magnetic field is knocked out cold.

01:23:52The core gets all overheated and can't circulate properly, which means no more magnetic field to protect the planet.

01:24:00It's like as if you were wearing nothing at the depth of the Mariana Trench.

01:24:03If it were possible, you'd be defenseless.

01:24:06And chilly.

01:24:08That's basically what happened to Mars.

01:24:10So now poor Mars is out there in the cold, unprotected from all those nasty cosmic rays.

01:24:16It's like going outside without sunscreen.

01:24:18Not a good idea.

01:24:20But at least we can learn from Mars' mistakes and make sure Earth doesn't have the same fate.

01:24:25Maybe we should start investing in some asteroid insurance.

01:24:29But trust me, the Red Planet isn't mean at all.

01:24:33It's actually pretty friendly.

01:24:35While Mars may seem to be pretty tough for Phobos, there's something that might be thriving with Mars' health.

01:24:41So get this, a team of scientists found a way to grow rice on Mars.

01:24:46Yep, you heard me right.

01:24:48They used MMS, not the outdated way to send pictures, but a special soil called Mojave Mars Simulant.

01:24:55It's supposed to mimic Martian soil.

01:24:57And here's the catch, Martian soil has these nasty percolate salts that can be toxic for plants.

01:25:03So the team grew three types of rice, one normal and two gene-edited with mutations that make them better at handling stress like drought or salinity.

01:25:13And guess what?

01:25:15The mutant strains were able to root in soil with one gram of percolate per kilometer.

01:25:20Take that, Martian soil!

01:25:22But hold up.

01:25:24The rice grown in the MMS didn't turn out as great as the ones grown in regular potting soil.

01:25:29So the team decided to mix a quarter of the potting soil with the Martian simulant, and looky there, the plants started developing better.

01:25:38Now these scientists aren't just thinking about feeding Martians.

01:25:42They also want to see if their findings can help grow crops in places on Earth with high salinity.

01:25:47And get this, the whole project started when two researchers met for coffee and decided to try growing plants together.

01:25:55Well, isn't that nice?

01:25:56I suspect you're about to say, hey, but if you want to grow rice on Mars, you'll have to ship insane amounts of water from Earth, and it's not easy to quench this plant's thirst.

01:26:07You're right.

01:26:09You need about 449 gallons of water to only grow a pound of rice.

01:26:14But guess what?

01:26:16Scientists made a groundbreaking announcement at the Lunar and Planetary Science Conference in Texas.

01:26:22They found a relic glacier near Mars' equator.

01:26:24That's right, water ice on Mars, even near the equator.

01:26:29This is huge news, and could mean there's even more ice just below the surface.

01:26:35It's not just any glacier.

01:26:37It's a relic glacier that's estimated to be 3.5 miles long and up to 2.5 miles wide.

01:26:44It's like the size of a small town.

01:26:46It's got all the features of a glacier, including crevasse fields and moraine bands.

01:26:51But get this, it's not actually ice.

01:26:54It's a salt deposit that formed on top of the glacier while preserving its shape.

01:26:59So, how did this salt deposit form?

01:27:02Well, it turns out that volcanic materials blanketing the region might have something to do with it.

01:27:08When these materials come into contact with water ice, sulfate salts may form and build up into a hardened crusty layer.

01:27:16Over time, erosion removed the volcanic materials, exposing the sulfates and revealing the glacier's unique features.

01:27:24This glacier is young, likely from the Amazonian geologic period.

01:27:28That means that Mars has had surface ice in recent times.

01:27:32Who knows what other icy secrets Mars is hiding?

01:27:36But hold your horses, there's still more research to be done.

01:27:39Scientists need to figure out if there's still water ice preserved underneath the salt deposit, or if it has disappeared entirely.

01:27:47And if there is still water ice at shallow depths near the equator, that could have major implications for human exploration.

01:27:55Imagine being able to extract water from the ground at a warmer location.

01:28:00That would be a game-changer.

01:28:02So let's see what else these scientists uncover about our favorite red neighbor.

01:28:07Maybe someday we'll even get to visit that salt glacier statue in person.

01:28:11See you next time!

01:28:13Imagine a still, frozen world.

01:28:17It's ancient, about 4.5 billion years old.

01:28:21It's barely heated by the rays of the sun and covered with a thick layer of ice.

01:28:26This world is smaller than our moon, but a bit larger than Pluto.

01:28:30Its name is Europa, the sixth satellite of Jupiter and one of the biggest moons in the solar system.

01:28:36But the coolest thing about this faraway place?

01:28:39It might host life.

01:28:42Astronomers consider Europa one of the most promising places in the solar system to search for new life forms.

01:28:49All because this moon has a huge saltwater ocean with a depth of 40 to 100 miles.

01:28:56Yes, it is hidden under a layer of ice that is estimated to be from 10 to 20 miles thick.

01:29:01But it is still potentially habitable.

01:29:03Astronomers claim that plumes of water erupt from cracks in the ice shell and release the contents of the moon's ocean into space.

01:29:12Of course, it's going to be challenging for any life-seeking missions to access such a deep environment.

01:29:18On the bright side, scientists already have some evidence that there are way shallower pools that probably lie much closer to the surface of the moon.

01:29:27They might be located even less than one mile under the surface.

01:29:30They might be located even less than one mile under the ice.

01:29:34And there are two great things about this news.

01:29:37First of all, it boosts the odds of life existing on Europa.

01:29:42And secondly, if it's true, it can make it easier for future missions to find these life forms, if there are any.

01:29:49Interestingly, the new discovery about these shallow pools came about by sheer luck.

01:29:54The scientist leading the research, Riley Kohlberg, accidentally saw a presentation of his colleague, a planetary scientist.

01:30:01That scientist showed a picture of double ridges on the surface of Europa.

01:30:06And Kohlberg remembered that he had seen similar ridges on Earth.

01:30:09But while such formations are rare on our planet, they are way more numerous on Europa.

01:30:15The following study suggested that the ridges on Jupiter's moon might be the result of a specific cycle, similar to that on Earth.

01:30:24In this cycle, liquid water freezes and then thaws inside an ice sheet, which is a rather high-pressure environment.

01:30:32This causes the sheet to move upward over and over again, creating a two-peaked structure.

01:30:38Or at least, that's what happens on Earth.

01:30:41If the processes on Europa are similar, it can prove the presence of shallow waters on the satellite.

01:30:47Of course, the temperature, pressure and chemistry are very different on Europa.

01:30:50And scientists don't know yet how the ice behaves there.

01:30:54That's why they can't understand how deep or large the water pockets are, or how long they need to refreeze.

01:31:01But what is more or less clear is that such under-ice environments on Europa are very likely to be protected from Jupiter's harsh radiation battering the satellite's surface.

01:31:10Which, in turn, increases the chances of life existing on Europa.

01:31:15Now, can we get back to the fact that the ocean on Europa seems to be salty?

01:31:20Red streaks on the satellite's surface might have this color due to their chemical content.

01:31:25They're likely a frozen mixture of water and salts.

01:31:28This is quite unusual because such a composition doesn't match any known substance here on Earth.

01:31:33As for yellow spots on Europa's surface, those might be caused by the presence of sodium chloride.

01:31:39You know this substance as good old table salt.

01:31:43Scientists tried to recreate the conditions on Europa in a lab.

01:31:46They discovered that by combining water, table salt, freezing temperatures, and high pressure, they could get a new kind of solid crystal.

01:31:55This substance might exist both at the bottom of Europa's ocean and on the moon's surface.

01:32:00But besides this information, researchers are in the dark.

01:32:05Hopefully, we'll find the answers to some of these questions around 2030.

01:32:10That's when a mission called Europa Clipper, which is going to be launched by NASA, will probably reach Europa.

01:32:16The mission is going to have several close flybys and figure out if any form of life can exist on the moon.

01:32:22The European Space Agency's JUICE, which stands for the Jupiter Icy Moons Explorer, is going to visit Europa in the next couple of years too.

01:32:31But Europa isn't the only place in the solar system that might host or once hosted life.

01:32:35In 2003, Mars Express, a spacecraft launched by the European Space Agency, discovered methane in the atmosphere of Mars.

01:32:44On our planet, the biggest part of this gas in the atmosphere is produced by living creatures, for example, by cattle digesting food.

01:32:52However, scientists think that methane was stable in the Martian atmosphere for about 300 years.

01:32:59And then, in 2006, the methane almost entirely vanished from the red planet.

01:33:05And it happened 600 times faster than researchers' models accounted for.

01:33:08The question, what or who generated the gas? And where did it go?

01:33:15Another Martian mystery is microbes that may be sleeping beneath the surface of Mars.

01:33:21There, they might have been protected from the harsh radiation coming from space for millions of years.

01:33:27Scientists simulated the conditions on Mars in a lab to check if it could possibly be true.

01:33:32And they were amazed to find out that bacteria could easily survive in such conditions for 280 million years.

01:33:40Which means that if life existed on Mars, we could find the evidence in the planet's subsurface by drilling into the Martian soil.

01:33:49Right now, there is no flowing water on Mars, and cells or spores would simply dry out.

01:33:56Plus, the surface temperature is similar to that of dry ice.

01:33:59In other words, the surface of the planet is deeply frozen.

01:34:03And still, there could be six types of bacteria and fungi living underground on the red planet.

01:34:09The most likely of them is nicknamed Conan the Bacterium due to its tough nature.

01:34:14Well, I guess time will show.

01:34:17Now, let's move to Venus.

01:34:19In 2020, scientists announced that in the toxic Venusian atmosphere, there was something that might mean the existence of life.

01:34:28Unfortunately, scientists didn't have any evidence, since there was no chance to collect any microbe specimens or snap any pictures of extraterrestrial life.

01:34:39But they claimed that they had discovered a chemical called phosphine there, and it was a big deal.

01:34:45If it wasn't some previously unknown chemistry that was producing this gas, then there could be some kind of microbial life involved in the process.

01:34:53Phosphine is made up of three atoms of hydrogen and one atom of phosphorus.

01:34:59This gas is toxic to any terrestrial life form that needs oxygen, including us humans.

01:35:05On our planet, phosphine can be found in places with no or little oxygen, for example, marshes and swamps.

01:35:12The gas is created by complex mixtures of bacteria living there.

01:35:15It can also be produced industrially.

01:35:17Come to think of it, phosphine isn't supposed to be in Venus' atmosphere altogether.

01:35:22This gas needs precise pressure and temperature, and tons of hydrogen to form.

01:35:27It wouldn't be all that surprising to find it on Saturn or Jupiter or famous gas giants.

01:35:33But on Venus? Totally unexpected.

01:35:37There's no way phosphine can be naturally produced on this planet.

01:35:40Tiny amounts of it can be created during volcanic eruptions, lightning storms, minerals blown up to the surface, or meteorites entering Venus' atmosphere.

01:35:49But not as much as astronomers thought they had observed.

01:35:52And it had to make scientists suspicious.

01:35:55But they were too happy about their discovery.

01:35:58They probably thought it meant there could be life on Venus.

01:36:02But even if this gas was created by some mysterious organisms, it would be a big deal.

01:36:07It would be a big question how they survived on Venus.

01:36:10On our planet, some microbes can thrive in environments with an acidity of 5%.

01:36:16But no more.

01:36:18On Venus, though, clouds are almost entirely made of acid, containing more than 90% of sulfuric acid.

01:36:25The Venusian atmosphere is also 50 times as dry as the driest place on our home planet.

01:36:29And indeed, in 2022, thanks to better and more high-resolution telescopes,

01:36:34it was concluded that there was no phosphine in Venus' atmosphere.

01:36:38Or even if there was, it was a very small amount.

01:36:41So far, we need to look for signs of life further away from Earth.

01:36:5911 astronauts needed to travel some 240,000 miles to get there.

01:37:04Their plan was to touch down on a place on the Moon called the Sea of Tranquility

01:37:08because it had good visibility and the terrain there was pretty smooth.

01:37:12Well, up until the last few moments of the flight,

01:37:15when all these big craters appeared that they had to avoid,

01:37:18they finally landed with just 30 seconds of fuel left.

01:37:21Ooh, that's called cutting it close.

01:37:23Hey, how would you like to land in your jetliner with only 30 seconds of fuel left?

01:37:27So, now you know.

01:37:29Later that day, July 20, 1969,

01:37:33Neil Armstrong stepped onto the lunar soil, saying,

01:37:36that's one small step for a man, one giant leap for mankind.

01:37:40The astronauts were planning to sleep before the first moonwalk,

01:37:43but they chose to go outside earlier than scheduled.

01:37:46They obviously couldn't sleep.

01:37:48I mean, could you?

01:37:50Since that first visit, our lunar satellite has accumulated

01:37:53quite a collection of memorabilia from Earth.

01:37:55Let's look at some of the most important

01:37:58and weird stuff that humans have left on the Moon.

01:38:01Take footprints for starters.

01:38:03I know, they're not technically objects,

01:38:05but the marks left by Neil Armstrong and Buzz Aldrin

01:38:08do show that humans have been there,

01:38:11just in case someone or something else drops by.

01:38:15Since the Moon doesn't have any wind or rain,

01:38:18the footprints should still be relatively untouched.

01:38:21NASA put in a lot of effort to make sure these footprints stayed protected.

01:38:25As well as the location of the initial Moon landing.

01:38:28Rules were set into place for future missions

01:38:31to make sure they wouldn't alter the initial site,

01:38:34as it's an important piece of history.

01:38:36Kind of like the National Park that you can't get to.

01:38:39Astronaut Charles Duke wanted to leave a photo of his family

01:38:43on the surface of the Moon.

01:38:45If that didn't make him the best dad ever,

01:38:47I don't know what would.

01:38:49He did take his family to the Moon, right?

01:38:51On the back of the picture, he wrote that he had come from Earth.

01:38:53He also added the date when he landed on the Moon,

01:38:56which was April 20, 1972.

01:38:59Now, there's a good chance that his family is no longer visible in the picture today.

01:39:04Because of the exposure to strong solar radiation,

01:39:07the colors in the photo have likely faded away by now.

01:39:10To this day, Charles Duke remains the youngest person to visit our Moon.

01:39:15He was 36 years old at the time of his mission.

01:39:18Now, there are many flags on the surface of the Moon, too.

01:39:20But the flags left there must have had a similar fate to Duke's photo.

01:39:24They're most likely discolored by now.

01:39:27During each lunar landing, a flag was planted as a tradition started by Apollo 11.

01:39:32This tradition continued with all future Apollo missions.

01:39:36The flags were made using metal poles to stretch the flag out

01:39:40so they could be seen on the Moon.

01:39:42But since there's no wind, they never move.

01:39:45Back in the 1600s, astronomer Galileo Galilei

01:39:48dropped two objects of different weights from the Leaning Tower of Pisa

01:39:52to show that the speed of the fall would be the same.

01:39:55In 1971, astronaut David Scott repeated the experiment on the Moon

01:40:00and proved Galileo's theory correct.

01:40:03He dropped a feather and a hammer at the same time,

01:40:06and as predicted, they both landed on the Moon's surface simultaneously.

01:40:10Fun fact, the feather came from the Air Force Academy's Falcon mascot named Baffin,

01:40:15with its permission of course.

01:40:16These objects were both left on the lunar surface.

01:40:19Now what about art pieces on the Moon?

01:40:22We've left some of those out there as well.

01:40:24The Fallen Astronaut sculpture was made by a Belgian artist

01:40:28and left behind by the astronauts of the Apollo 15 mission.

01:40:32It was a small statue requested by David Scott, the head of the mission.

01:40:36Scott said the statue was to memorialize the astronauts and cosmonauts

01:40:41who gave their lives for the advancement of space exploration.

01:40:43Meanwhile, astronaut Alan Shepard even played some golf on the Moon

01:40:47during his mission on Apollo 14.

01:40:50He brought a golf club head, yes, he got permission first,

01:40:53and attached it to a tool.

01:40:55Then he tried to hit two golf balls.

01:40:58Hey, it's hard to do in a clunky space suit.

01:41:01He did better on the second one.

01:41:03It's safe to say that he didn't bring the golf balls back,

01:41:06and they should still be there on the Moon.

01:41:09For…

01:41:11There's yet a message from Queen Elizabeth II there.

01:41:15The monarch prepared a message which accompanied Neil and Buzz

01:41:18to Tranquility Base during the Apollo 11 mission.

01:41:21It was written on a tiny disc the size of a coin

01:41:24and also featured messages from over 70 other leaders from all over the world.

01:41:29I'll bet the printing was really small.

01:41:31Her message said she was proud of the astronauts and their accomplishments

01:41:35and hoped their journey would benefit all of humanity.

01:41:37The disc was then placed where Armstrong and his team first landed on the Moon.

01:41:42After they returned, they met the Queen at Buckingham Palace.

01:41:46Their encounter was memorable too.

01:41:48Neil Armstrong almost couldn't speak to the Queen at all because he had a cold.

01:41:52Another astronaut named Mike Collins was so nervous about the protocol,

01:41:57he almost fell down the stairs.

01:41:59Now some objects that exist today on the Moon weren't left there on purpose.

01:42:03One of the most interesting moments of the Apollo 11 mission

01:42:07was when Neil and Buzz were getting ready to go back to Earth.

01:42:11They had to chuck everything they didn't need so they wouldn't be weighed down at liftoff.

01:42:16They also needed to store all the rock samples they had gathered from the lunar surface.

01:42:20This created a toss zone that archaeologists could potentially study one day.

01:42:25Waste like this acts as a timeline for Earth's history,

01:42:29but it can also help us understand what happens to objects

01:42:33that spend a lot of time on the surface of the Moon.

01:42:35Now most astronauts became pretty sentimental when strolling on the lunar dust.

01:42:40And who could blame them?

01:42:42They were thousands of miles away from their families.

01:42:45So that's why, in 1972, NASA astronaut Eugene Cernan

01:42:50wrote his daughter's initials, TDC, in the dust on the Moon

01:42:54and gave a speech before leaving.

01:42:56He said,

01:42:58We leave as we came, and hopefully we'll return with peace and hope for all.

01:43:02Unfortunately, this marked the end of the Apollo lunar missions.

01:43:06Technically, his daughter's initials should still be there on the surface of the Moon,

01:43:10just like all the astronauts' footprints.

01:43:13Can you believe it's been more than 50 years since people started exploring the Moon?

01:43:18No worries, though, as NASA's been preparing for future lunar explorations for quite some time.

01:43:24This new mission is called Artemis,

01:43:26and it aims to build some sort of settlement out there.

01:43:28This way, the Moon can be studied in safe conditions for longer periods of time.

01:43:34For starters, NASA launched Orion,

01:43:37a spacecraft without a crew on board, to orbit the Moon and come back to Earth.

01:43:41This was a test drive.

01:43:43Before NASA transports people to the Moon again using newer technology,

01:43:47all safety measures need to be worked out and confirmed.

01:43:50But one day soon, Orion is going to take astronauts back to the Moon.

01:43:55One cool thing about this spacecraft is that it comes with a launch abort system,

01:44:00which is meant to keep astronauts safe in case something goes bad during the launch.

01:44:04It also features a special service module,

01:44:07which is like a battery that fuels and propels Orion through space.

01:44:10It also supplies astronauts with water, oxygen, and power, and provides temperature control.

01:44:16But Artemis also looks to build a long-term human settlement on our satellite,

01:44:21somewhere around the 2030s.

01:44:22However, searching for a cozy place on the Moon isn't as easy as you'd think.

01:44:27Thankfully, NASA specialists produced an ingenious idea.

01:44:31They found some lava tubes on the surface of the Moon,

01:44:34and they have pretty steady temperatures inside.

01:44:36The main problem with the first Moon landing back in 1969 was extreme temperature fluctuations.

01:44:42So these caves might be the perfect solution.

01:44:45Not only is the temperature in there suitable for humans,

01:44:48but they could also help shield astronauts from cosmic rays, solar radiation, and meteorites.

01:44:54It's also good news that we have similar structures here on Earth.

01:44:58Before we get back to space, we can study them to better understand those found on the Moon.

01:45:03Here on Earth, these holes form once the top of a stream of lava solidifies,

01:45:08and the molten rock inside drains away, creating this tube.

01:45:12You know how it all started, 13.8 billion years ago, with the Big Bang?

01:45:18Bam! No, no, wait, I can do better.

01:45:21No, that's... never mind.

01:45:23And the Universe has been expanding ever since.

01:45:27At its young age, it was all made of gas, mostly helium and hydrogen.

01:45:32For billions of years, the gas has expanded and cooled down.

01:45:37Meanwhile, galaxies, stars, and other mysterious things in space we try to explore today

01:45:43formed because of gravitational forces.

01:45:46And in that chaos, just like in middle school, about 4.6 billion years ago,

01:45:52our magnificent planet was born too.

01:45:55It all started as a disk of gas and dust that orbited the young Sun,

01:46:00just the same way it was with the rest of the planets in our solar system.

01:46:03This disk consisted of dust particles of different sizes and gas.

01:46:09They were circling the Sun at different speeds and in orbits that weren't stable and predictable.

01:46:15They were bumping into each other all the time.

01:46:18These particles grew from very small grains of dust into boulders,

01:46:22then later into bigger objects called planetesimals

01:46:26that had a range from miles to hundreds of miles in diameter.

01:46:30And these planetesimals that were orbiting the Sun within the disk

01:46:34had gravitational force strong enough to pull other objects from the neighborhood

01:46:39out of their orbits and collide with them.

01:46:42As they were constantly hitting each other, they got bigger and bigger

01:46:46until some got to the size of thousands of miles in diameter.

01:46:50That's nearly the size of Mars and the Moon.

01:46:53We know these things because of meteorites.

01:46:55They come from different places all over our solar system

01:46:59and bring all kinds of materials to our planet,

01:47:02giving us something cool to study and learn about our solar system and how it formed.

01:47:08These materials include very small pieces of dust and rock

01:47:12that have gone through the chaos and survived those rough times

01:47:16even before the planets were created.

01:47:19Meteorites also brought pieces of asteroids and planetesimals left behind

01:47:23after the planet-forming process ended.

01:47:26As these objects were forming, some radioactive elements were left

01:47:31trapped inside the minerals that, again, were part of them.

01:47:35That's how scientists could tell how old they were.

01:47:39But the final stage of Earth's formation,

01:47:42and generally this whole chaos that was happening in our solar system,

01:47:46may have taken a little bit longer, possibly even up to a hundred million years more.

01:47:51That's when the last enormous impact was, and the Earth finally reached its full size.

01:47:57What actually happened is that it hit another object which was nearly as large as Mars.

01:48:03This collision was so strong that the impact produced enough energy

01:48:08to vaporize some of the metal and rock, both from the Earth and the Mars-sized object.

01:48:13And this vapor created a disk that was surrounding our planet.

01:48:18That disk cooled and clumped together at some point, which is when we got our Moon.

01:48:24Our Moon was the result of impact debris,

01:48:27which was a combination of hot gas and molten rock.

01:48:31There are some theories of how the Moon formed, though.

01:48:34One claims it broke off from the Earth.

01:48:37Another one says the Moon formed somewhere else in our solar system,

01:48:41and at some point, as it was wandering around,

01:48:44it got so close to Earth that it ended up captured by its gravity.

01:48:49And fans of the third theory believe the Moon and the Earth formed at the same time,

01:48:55from the same protoplanetary disk.

01:48:58Before the Moon formed, the Earth was a much different place.

01:49:02If you could have just one day on Earth without the Moon,

01:49:05you'd be first surprised by the days and nights.

01:49:08They wouldn't be as stable as they are today,

01:49:11because the Moon helps to keep the Earth's axis stable.

01:49:15Days were shorter back then.

01:49:17The Earth had been rotating much faster before the Moon formed.

01:49:21Its gravitational pull slowed the rotation of our planet,

01:49:25which means days got longer.

01:49:27The Earth's rotation is getting slower through time,

01:49:30but at a really small rate.

01:49:32Some predictions say that in a billion years,

01:49:35a typical day will be between 25.5 and 31.7 hours long.

01:49:42If 24 hours is not enough time for you,

01:49:45just wait a billion years.

01:49:47But yeah, if you're the type of person that likes to take things slowly,

01:49:52you'd definitely have to hurry back then.

01:49:54Although, there weren't many things you could do back then,

01:49:58than to fill your time, besides, you know,

01:50:00sailing across the hot lava,

01:50:03collecting rocks,

01:50:05or hoping not to get hit in the head by some fierce meteorite

01:50:08falling onto our planet.

01:50:10But if you were patient enough,

01:50:13maybe you'd see something really cool,

01:50:16water coming onto our planet for the first time.

01:50:20There was a rain of fiery meteors coming from the sky,

01:50:23and they kept slamming into our young Earth.

01:50:26It looked devastating at first,

01:50:27but some of this falling debris probably held water.

01:50:32Many believe the asteroids and comets that bumped into our home planet

01:50:36carried tiny amounts of water.

01:50:38But considering this meteorite shower lasted more than 20 million years,

01:50:43maybe even up to 200 million years,

01:50:46it's not that unusual that after a while,

01:50:49puddles of water started to collect across the surface.

01:50:53And as the water evaporated within the atmosphere,

01:50:55it would fall back down,

01:50:58forming lakes, rivers, seas, and eventually oceans.

01:51:02Only at that point,

01:51:04there was a chance for some primitive life to evolve sometime in the future.

01:51:08Earth started its transition from a hot ball of magma

01:51:12to the world we know today.

01:51:14Before that, it would be too hard for life to exist there.

01:51:18Even if it had happened somehow,

01:51:21all those meteor and asteroid collisions

01:51:23would have probably destroyed it.

01:51:26Also, you wouldn't be able to survive without an oxygen tank.

01:51:30The Earth did have an atmosphere,

01:51:32but it wasn't like the one we have today.

01:51:35Scientists believe it was composed of water vapor,

01:51:38methane, ammonia,

01:51:40and some other gases released from volcanic activity.

01:51:43Basically, it was too toxic,

01:51:46since there were volcanic eruptions all the time.

01:51:49And the temperatures were way higher,

01:51:51so just standing at these early stages of Earth

01:51:54wouldn't be such a pleasant experience.

01:51:57Also, there could even be some form of life at that time.

01:52:01In its early stages, when everything was so chaotic,

01:52:05it wasn't covered in oceans, trees, or stunning landscapes like today,

01:52:10but in molten magma.

01:52:12I mean, the earliest form of life we know about

01:52:15are fossils of microorganisms found in hydrothermal vents.

01:52:19And they're thought to be 1.4 billion years old.

01:52:23And scientists assume the earliest time for life to show on Earth

01:52:27could be 4.2 billion years ago, give or take.

01:52:31So, with the right equipment,

01:52:33you could even see some single-celled organisms like bacteria

01:52:37somewhere across our chaotic planet,

01:52:40even before the Moon was there.

01:52:42The Moon's gravitational pull on the Earth

01:52:45creates tides in the ocean,

01:52:46which means it probably helped mix and circulate ocean water,

01:52:50maybe even shape them.

01:52:52The tides without the Moon would be much smaller,

01:52:56because the gravitational pull is what causes the tides to rise and fall.

01:53:01The Moon also affects life in the ocean.

01:53:04Over time, animals in the ocean have changed

01:53:07and adapted to the changing water levels caused by the Moon's gravity.

01:53:12Even just the Moonlight has a big effect on sea creatures.

01:53:16For example, corals use the Moon's cycle

01:53:20to release their eggs at the same time

01:53:23and with stronger tides to help carry the eggs.

01:53:26Baby sea turtles use the Moon's light shining on the water

01:53:30to guide them from their nest to the ocean.

01:53:33Who knows which directions life on the Earth would have taken

01:53:36if, at some point billions of years ago,

01:53:39we didn't get our lunar buddy to follow us along the way.

01:53:47You step on the surface of the Moon.

01:53:50It's unusual.

01:53:52You definitely feel lighter here, and it's easier to walk.

01:53:55You decide to check out that obsessive idea of yours,

01:53:58jump on Earth's natural satellite,

01:54:00and even despite your bulky space suit,

01:54:03you literally fly up into the air.

01:54:05Woo-hoo!

01:54:07Anyway, you continue your walk on the surface of the Moon

01:54:10when you feel something strange.

01:54:12The ground under your feet is…

01:54:14Is it shaking?

01:54:16Maybe the earthquake has just started on the Moon.

01:54:18But that's simply impossible.

01:54:20Or is it?

01:54:22Surprisingly, your gut feeling hasn't let you down this time.

01:54:24Moonquakes do exist.

01:54:26In fact, there are four types of moonquakes

01:54:29that are strong enough to be detected from a large distance.

01:54:32There are deep moonquakes occurring more than 430 miles below the surface.

01:54:36Then there are meteoroid impacts.

01:54:39Thermoquakes occur when the frigid lunar crust expands.

01:54:42It happens when the morning sun illuminates the satellite

01:54:46during a two-week-long deep freeze lunar night.

01:54:49And there are also shallow moonquakes.

01:54:52They're the only ones that are similar to earthquakes on our planet.

01:54:55Shallow moonquakes happen 12 to 19 miles below the surface,

01:54:59and they're the most powerful and dangerous.

01:55:02Between 1972 and 1977,

01:55:05the Apollo seismic network recorded 28 such moonquakes,

01:55:10and some of them measured more than 5 on the Richter scale.

01:55:12On Earth, such an earthquake is strong enough

01:55:15to crack plaster and move heavy furniture.

01:55:18Plus, shallow moonquakes are very long-lasting

01:55:21when compared to earthquakes.

01:55:23Once they get going, they can continue for up to 10 minutes.

01:55:26As for the average earthquake,

01:55:28it typically continues for 10 to 30 seconds.

01:55:31Scientists are still not sure what causes shallow moonquakes,

01:55:34and even where exactly they occur.

01:55:37One of the theories is that moonquakes happen

01:55:39at the rims of large, relatively young craters.

01:55:42that probably slump from time to time.

01:55:45Interestingly, the Moon and Earth

01:55:48aren't the only places where earthquakes occur.

01:55:50No, scientists have recorded quakes, tremors,

01:55:53vibrations, and shakes in other regions of our solar system, too.

01:55:57Let's take Mercury, for example.

01:55:59A few years ago, scientists discovered that this planet was shrinking,

01:56:03and that's why it seems to be so tectonically active.

01:56:07Or Venus.

01:56:09This world is a tectonic puzzle for experts.

01:56:10At the moment, Venus has no tectonic plates,

01:56:14and it might have never had them,

01:56:16but its surface has folds and faults

01:56:18and looks as if it could have tectonic plates.

01:56:21On the other hand, these features might have appeared

01:56:24because of other processes,

01:56:26for example, volcanic activity.

01:56:28But even though we haven't observed any Venusquakes,

01:56:31scientists believe they could detect them,

01:56:34since their vibrations seem to ripple through

01:56:36the thick atmosphere of the planet.

01:56:38Now, Mars.

01:56:40We're sure that this planet is seismically active.

01:56:43NASA's lander placed a seismometer on the surface of the red planet,

01:56:47and in 2019, it managed to measure its first Marsquake.

01:56:51After that, the lander continued to record quakes.

01:56:54But they were so weak that if they happened on our planet,

01:56:58they'd be completely covered by the background noise of Earth's oceans.

01:57:02But a space body doesn't have to be a full-fledged planet

01:57:05to have active tectonics.

01:57:07Let's take Pluto.

01:57:08This dwarf planet is geologically active at the moment.

01:57:12In 2014, NASA's New Horizons spacecraft

01:57:15was flying through the Pluto system

01:57:17when it recorded complex geological features on this dwarf planet.

01:57:22Scientists concluded that Pluto might have quakes,

01:57:25or should I call them Plutoquakes,

01:57:27when its liquid water ocean freezes and thaws

01:57:30beneath the dwarf planet's icy crust.

01:57:32Jupiter's moons Europa and Io,

01:57:35as well as Saturn's moons Titan and Enceladus,

01:57:38are also geologically active despite their small size.

01:57:42Their features range from volcanoes and water plumes

01:57:45to potential subsurface oceans.

01:57:47Now, I bet you don't know these cool facts

01:57:50about earthquakes that occur on our planet.

01:57:52There's one place on Earth

01:57:54where a whopping 90% of all earthquakes occur.

01:57:57It's called the Ring of Fire,

01:57:59and it stretches around the Pacific Ocean

01:58:01from New Zealand all the way to South America.

01:58:04Hmm, looks to me more like a horseshoe.

01:58:06Anyway, experts claim that these countless earthquakes

01:58:10are caused by the abundance of volcanoes in that region

01:58:13and the constant movement of the tectonic plates.

01:58:16Around half a million earthquakes happen on Earth every year,

01:58:20but many of them occur very, very deep in the Earth's crust,

01:58:23and only special equipment can detect them.

01:58:26We feel around 20% of earthquakes,

01:58:29and only 100 of them can cause damage.

01:58:32The largest recorded earthquake occurred in Chile

01:58:34in May 1960.

01:58:37It was a magnitude 9.5 on the Richter scale.

01:58:40It was truly devastating.

01:58:42During that earthquake, seismographs detected

01:58:45and recorded seismic waves that traveled all over the world.

01:58:48They shook the planet for many days.

01:58:51As for the most powerful earthquake that occurred in the US,

01:58:54it was 9.2 and happened in Alaska.

01:58:57By the way, Alaska, along with California,

01:59:00is the most earthquake-prone state in the US

01:59:02and one of the most seismically active regions in the world.

01:59:06A magnitude 7 earthquake occurs there almost every year.

01:59:10A mega-earthquake can actually shorten the length of a day

01:59:13for the entire planet.

01:59:15NASA claims that really large earthquakes

01:59:18can shift our planet's axis and, thus,

01:59:21change the duration of a day.

01:59:23Now, of course, you won't notice it

01:59:25since this change is measured in microseconds,

01:59:28and one microsecond is one millionth of a second.

01:59:30Scientists think that the 9.1 Sumatra earthquake,

01:59:34which occurred in 2004,

01:59:36shortened the day by 6.8 microseconds.

01:59:39Now, not even the best specialists can predict an earthquake.

01:59:43That's mostly because the mechanisms that trigger earthquakes

01:59:46are extremely deep underground.

01:59:49But, these days, people have learned

01:59:51how to figure out a more precise time frame

01:59:53of when an earthquake might occur.

01:59:56Earthquakes can be triggered by volcanic eruptions

01:59:58or, let's say, meteor impacts.

02:00:01But most of them are caused by the movements

02:00:04of our planet's tectonic plates.

02:00:06Earth's surface consists of 15 to 20

02:00:09constantly moving tectonic plates.

02:00:11Pressure increases when they shift,

02:00:13and this can make the crust of our planet break.

02:00:16San Francisco is moving toward Los Angeles

02:00:19right at this moment.

02:00:21The speed of its movement is about 2 inches per year.

02:00:24That's as fast as your fingernails grow.

02:00:25It's happening because the two sides

02:00:28of the San Andreas Fault,

02:00:30which is the continental fault

02:00:32extending 750 miles through California,

02:00:35are slipping past each other.

02:00:37So, in several million years,

02:00:39Los Angeles and San Francisco

02:00:41will be neighbors.

02:00:43Lakes, ponds, and canals

02:00:45become slightly warmer

02:00:47and start to stink before an earthquake.

02:00:49It happens because gases get released

02:00:51when tectonic plates shift.

02:00:52Most animals feel these signs

02:00:54and change their behavior.

02:00:56For example, scientists noted toads

02:00:59completely disappearing

02:01:01before an earthquake in Italy in 2009.

02:01:04But as soon as the natural disaster was over,

02:01:06they returned.

02:01:08Even after an earthquake is over,

02:01:10you might still see water sloshing around

02:01:12in your swimming pool.

02:01:14There's no need to worry.

02:01:16This is a phenomenon called a seiche.

02:01:18The water can keep sloshing around

02:01:20for hours after the earthquake is over.

02:01:22For example,

02:01:24the pool at the University of Arizona

02:01:26lost some water from a seiche

02:01:28caused by an earthquake in Mexico

02:01:30that occurred 1,200 miles away.

02:01:33On February 27, 2010,

02:01:36a massive earthquake started in Chile.

02:01:39It measured 8.8 on the Richter scale.

02:01:41As a result,

02:01:43Earth's crust in that region

02:01:45was ripped so dramatically

02:01:47that a city called Concepcion

02:01:49moved 10 feet to the west.

02:01:50Another earthquake resulted

02:01:52in the tallest mountain in the world,

02:01:54Everest, shrinking by one inch.

02:01:57It happened in 2015

02:01:59when a magnitude 7.5 earthquake

02:02:01caused several Himalayan mountains

02:02:03to decrease in size.

02:02:05The Japanese used to believe

02:02:07that earthquakes were caused by namazu,

02:02:09a giant catfish

02:02:11that lived submerged in the mud

02:02:13under the Japanese islands.

02:02:15The fish would thrash about,

02:02:17causing seismic activity.

02:02:18As for the ancient Greeks,

02:02:20they were sure

02:02:22that a powerful sea deity, Poseidon,

02:02:24produced earthquakes

02:02:26by hitting his trident against the Earth

02:02:28when he was angry.

02:02:30According to Hindu mythology,

02:02:32eight elephants hold Earth in place.

02:02:34They are, in turn,

02:02:36balanced on the back of a ginormous turtle

02:02:38standing on the coils

02:02:40of an even larger snake.

02:02:42And every time any of these animals moves,

02:02:44an earthquake occurs.

02:02:46So Mars has two moons,

02:02:48Phobos and Deimos.

02:02:50And apart from the bizarre shape,

02:02:52there's nothing remarkable about them,

02:02:54except for one thing.

02:02:56Not so long ago,

02:02:58scientists discovered a strange phenomenon

02:03:00on the surface of Phobos,

02:03:02and they still can't find

02:03:04any explanation for it.

02:03:06What is this phenomenon?

02:03:08And what does it tell us

02:03:10about the history of our solar system?

02:03:12Let's find out!

02:03:14American astronomer Asaf Hall

02:03:16discovered Phobos and Deimos

02:03:18back in 1877.

02:03:20Did you know that all the planets

02:03:22in our solar system

02:03:24are named after Greek and Roman deities?

02:03:26For example,

02:03:28Mars, or Aries,

02:03:30is the famous deity of war.

02:03:32That's why the satellites of this red planet

02:03:34were named after the sons of Aries,

02:03:36Phobos and Deimos.

02:03:38These beautiful names

02:03:40actually have creepy meanings.

02:03:41Fear and horror.

02:03:44In 1971,

02:03:46NASA's Mariner 9 telescope

02:03:48took the first pictures.

02:03:50That's how we found out

02:03:52that these guys weren't at all

02:03:54like our moon.

02:03:56They had this weird shape,

02:03:58a strange and unstable orbit.

02:04:00Moreover,

02:04:02there are no other moons

02:04:04in the solar system

02:04:06that move as close to their parent planet

02:04:08as these two.

02:04:09But even though they are

02:04:11very close to Mars,

02:04:13if you were standing on the surface

02:04:15of the red planet,

02:04:17you would hardly be able to see them.

02:04:19That's because the curvature of Mars

02:04:21hides Phobos and Deimos from view.

02:04:23Even if you were somewhere

02:04:25on the equator,

02:04:27Phobos would look like

02:04:29an ordinary asteroid to you,

02:04:31and Deimos would look like a star.

02:04:33All because these satellites

02:04:35are basically crumbs

02:04:37compared to our moon.

02:04:39Which is ironic

02:04:41considering their mighty names.

02:04:43Anyway,

02:04:45it seems that everything

02:04:47should be pretty clear

02:04:49with these two satellites.

02:04:51But nope,

02:04:53there's a problem.

02:04:55You see,

02:04:57scientists reconstruct

02:04:59the history of space

02:05:01based on the traces

02:05:03found on different space objects.

02:05:05Dents, scratches, cracks,

02:05:07all these things

02:05:09Phobos and Deimos

02:05:11were twins.

02:05:13But then,

02:05:15NASA's Viking orbiter

02:05:17took new photos of the satellites.

02:05:19And that's when they discovered

02:05:21a significant difference

02:05:23between the two.

02:05:25The entire surface of Phobos

02:05:27was covered with huge grooves.

02:05:29Those were a series

02:05:31of long, deep pits

02:05:33stretching from one end

02:05:35of Phobos to the other.

02:05:37You may say,

02:05:39I've seen grooves and scratches,

02:05:41but none of them

02:05:43has as many as Phobos.

02:05:45It's completely covered in grooves

02:05:47and they're huge,

02:05:49up to 12 miles long

02:05:51and 660 feet wide.

02:05:53And that's not all.

02:05:55Some of these grooves

02:05:57intersect with others.

02:05:59This means that Phobos

02:06:01has experienced not one

02:06:03but many traumatic events.

02:06:05But what exactly happened to it?

02:06:07Actually, scientists

02:06:09and these theories

02:06:11can tell us not only

02:06:13about the past of Phobos

02:06:15but also predict its future.

02:06:17Theory 1. Asteroid Impact

02:06:19Well, the first suspect

02:06:21is quite obvious.

02:06:23There's a large,

02:06:25almost 6-mile-wide crater

02:06:27on Phobos.

02:06:29It's called Angeline Stickney.

02:06:31It was named after

02:06:33the wife of Asaph Hall,

02:06:35the scientist who

02:06:37discovered the satellites.

02:06:39When it hit Phobos,

02:06:41the impact was so strong

02:06:43that it left a large crater.

02:06:45And the effect of the collision

02:06:47left a bunch of grooves

02:06:49everywhere on Phobos.

02:06:51It sounds logical at first.

02:06:53However, scientists have noticed

02:06:55a flaw in this theory.

02:06:57They learned that these grooves

02:06:59actually formed not inside the crater

02:07:01but next to it.

02:07:03So it wasn't a collision

02:07:05that created them.

02:07:07Besides, what about those grooves

02:07:09and the cosmic coincidence?

02:07:11Well, the search for truth continued.

02:07:13Theory 2.

02:07:15It's all because of space debris.

02:07:17Yes, there's a difference

02:07:19between these two theories.

02:07:21In this case,

02:07:23the grooves aren't a direct consequence

02:07:25of the collision.

02:07:27Rather, it goes something like this.

02:07:29Something crashed into Phobos.

02:07:31This impact caused

02:07:33a bunch of rocks

02:07:35to be thrown into space.

02:07:37Some of them were lost

02:07:39and sent back to Phobos.

02:07:41Passing next to the moon

02:07:43at a steep angle,

02:07:45they would crash into it,

02:07:47jumping away, and so on.

02:07:49And since the gravity of Phobos

02:07:51is very weak,

02:07:53perhaps they couldn't stick to it.

02:07:55In other words,

02:07:57these rocks were continuously

02:07:59pulled toward and pushed off

02:08:01of the satellite for many,

02:08:03many years.

02:08:05This theory explains

02:08:07the intersecting grooves.

02:08:09But there's another problem.

02:08:11We don't see any boulders on Mars

02:08:13or on the surface of its moons.

02:08:15But all this debris

02:08:17was supposed to get trapped by gravity

02:08:19and remain somewhere in the planet's orbit.

02:08:21This, or simply become part of Phobos.

02:08:24In other words,

02:08:26if this were true,

02:08:28we'd find evidence of this theory

02:08:30under layers of dust.

02:08:32But that didn't happen,

02:08:34so this explanation

02:08:36didn't satisfy astronomers either.

02:08:37Let's look for the culprit.

02:08:39Maybe the grooves have nothing to do

02:08:41with Stickney Crater at all.

02:08:43Maybe the real culprit

02:08:45is something else,

02:08:47something even more powerful.

02:08:49Could it be

02:08:51Mars itself?

02:08:53Theory 3

02:08:55Mars is a twist villain

02:08:57The previous theories imply

02:08:59that Phobos and Deimos

02:09:01were originally pieces of Mars.

02:09:03Like once upon a time

02:09:05they broke away from it

02:09:07but what if that wasn't the case?

02:09:10Observations made

02:09:12by NASA's Mars Global Surveyor

02:09:14show that Phobos and Deimos

02:09:16are made up of elements

02:09:18which are mainly found

02:09:20in meteorites and asteroids.

02:09:22So, what if Phobos and Deimos

02:09:24are asteroids?

02:09:26There's an asteroid belt

02:09:28between Mars and Jupiter.

02:09:30Given the size, shape,

02:09:32and composition of Phobos and Deimos,

02:09:34scientists have suggested

02:09:35that once upon a time

02:09:37they belonged to this belt.

02:09:39However, one day

02:09:41they flew out of it

02:09:43and then gravity pulled them to Mars.

02:09:45This phenomenon

02:09:47is called asteroid capture.

02:09:49It's very strange though.

02:09:51Yeah, the asteroid capture

02:09:53isn't uncommon

02:09:55but these two have been

02:09:57flying next to Mars

02:09:59for what, billions of years?

02:10:01It's weird that their orbits

02:10:03have remained the same.

02:10:05They hardly capture any asteroids.

02:10:07In theory,

02:10:09they should have separated from Mars

02:10:11at the first opportunity.

02:10:13However, this didn't happen.

02:10:15It means that somehow

02:10:17they got stuck

02:10:19and Mars immediately began

02:10:21to destroy them.

02:10:23Yep, an unexpected twist.

02:10:25In this version,

02:10:27Mars turns out to be a villain.

02:10:29By studying the past,

02:10:31we've found some evidence

02:10:33of future crimes.

02:10:35For example,

02:10:37the gravitational forces

02:10:39between Mars and Phobos.

02:10:41The Moon and Earth

02:10:43also exchange these,

02:10:45slightly distorting each other.

02:10:47But, since Phobos

02:10:49is much closer to Mars,

02:10:51the impact of gravitational forces

02:10:53is much stronger.

02:10:55In other words,

02:10:57the gravity of Mars

02:10:59is gradually destroying Phobos.

02:11:01Every 100 years,

02:11:03the satellite gets

02:11:05bigger and bigger.

02:11:07The smaller it gets,

02:11:09the more the tidal forces impact it,

02:11:11creating strange grooves

02:11:13and scratches on Phobos.

02:11:15Yep, somewhere in

02:11:1730 to 50 million years,

02:11:19Phobos will either

02:11:21collide with Mars

02:11:23or disintegrate

02:11:25and turn into a bunch

02:11:27of small rocks.

02:11:29And then Mars will also have rings

02:11:31like Saturn and Neptune.

02:11:33That's why Phobos

02:11:35is so famous.

02:11:37But the dramatic backstory

02:11:39of Phobos gives us an idea

02:11:41of how dynamic

02:11:43extraterrestrial objects can be.

02:11:45The more we learn about them,

02:11:47the more we discover

02:11:49about the secrets of the origin

02:11:51of not only Mars,

02:11:53but also other objects

02:11:55in our solar system.

02:11:57If one day we really

02:11:59colonize Mars,

02:12:01studying its moons

02:12:03can help us a lot.

02:12:05Thanks for watching,

02:12:07and stay on the Bright Side!

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