- 14 hours ago
Join us on a fascinating journey as we uncover the potential for life on four moons of Uranus, while also exploring the looming threat of big asteroids and our limited safety window of 1,000 years. Discover the mysteries and challenges that lie within our own solar system.
Category
🎈
FunTranscript
00:00Ah, well-deserved vacay, finally. This time you're off to see something new.
00:05It's an ocean on one of the Uranus' moons.
00:08Alright, just kidding. This destination is not a vacation spot yet.
00:12But yeah, there are definitely some impressive oceans out there.
00:16Hey, don't say you thought oceans can only be found on Earth.
00:20But before diving into Uranus' moons' oceans, let's talk about Uranus itself first.
00:26The seventh planet from the sun, and the coolest cat in the solar system.
00:30It's got 27 moons, and four of them might technically have oceans.
00:35That's more than most people have friends.
00:37All these moons are like Uranus' mini-me's.
00:40They tilt at the same crazy angle as their parent planet, 98 degrees to be exact.
00:45And Uranus is so unique that it orbits the sun on its side.
00:48That means its equator is almost at a right angle to its orbit.
00:52Talk about rebellious.
00:54But why is Uranus like this?
00:56Well, some astronomers reckon it's because it got knocked on its side by a massive collision with another planet.
01:02And that impact might have actually created Uranus' moons.
01:05Fun fact, those moons have pretty particular names.
01:08Instead of mythical figures, most of them are named after Shakespearean characters.
01:12I mean, who needs Zeus when you've got Juliet and Desdemona?
01:16Discovering these moons isn't easy.
01:18They're super dark and located billions of miles away from the sun.
01:22It's like trying to find a needle in a haystack.
01:25Except the needle is smaller than your pinky finger.
01:27These 27 satellites are divided into three groups.
01:3113 inner moons, 5 major moons, and 9 irregular moons.
01:36The irregular ones are rebels with retrograde orbits,
01:38while the others are prograde and go with the flow of Uranus.
01:43The big boys are Miranda, Ariel, Umbriel, Titania, and Oberon.
01:48And they're all in Uranus' equatorial plane and are big enough to be round.
01:52They've got craters and canyons and cliffs.
01:55Oh my.
01:56These moons also formed from a giant impact that tilted Uranus on its axis.
02:00That's why they're all tilted too.
02:02And because of that tilt, they have crazy seasonal cycles just like Uranus itself.
02:07But we haven't found all of Uranus' moons yet.
02:10The little irregular ones are sneaky and hard to detect.
02:13So who knows how many more there could be.
02:16But let's talk about the really cool stuff.
02:18What these moons are made of.
02:20We're not entirely sure, but we think they're made of rock and ice.
02:24Miranda is the most icy one.
02:25While the inner moons are probably just dusty.
02:28And the ones beyond Oberon's orbit?
02:30They're likely captured asteroids that could be rocky.
02:32Or icy.
02:33Or who knows what.
02:35But here's what really sets Uranus' moons apart.
02:37They're all tilted together with Uranus.
02:40That's wild.
02:41Exploring these moons could teach us so much about how ocean worlds form.
02:45And stay active.
02:47Titania is the biggest moon of Uranus.
02:49But it's still less than half the size of Earth's moon with a diameter of about 1,000 miles.
02:54It's also the eighth heaviest moon in the whole solar system.
02:57They named it after the Fairy Queen in a Midsummer Night's Dream.
03:01Titania's color is gray, and it has some shiny patches that scientists think are frost.
03:05It's made up of a mix of ice and rock, just like all the other moons close to Uranus.
03:11Oberon is the next biggest moon of Uranus, named after the Fairy King in Shakespeare's play.
03:16It's almost the same size as Titania, and also has a half-ice slash half-rock composition.
03:21But Oberon's surface is way more cratered than the other Uranian moons.
03:26Umbriel and Ariel are the third and fourth-largest moons of Uranus, with diameters of 726 miles and 718 miles,
03:34respectively.
03:36Umbriel is named after a bad spirit in an old poem, and it's the darkest of all Uranus' big moons.
03:42It only reflects 16% of the light that hits it.
03:46Scientists don't know why it's so dark, but they think a bright ring around a crater might be caused by
03:50frost deposits.
03:51Ariel is the brightest of all Uranus' big moons, and it reflects over a third of the light that hits
03:57it.
03:58It's named after characters in both Pope's poem and Shakespeare's play.
04:02Ariel looks like the youngest moon, because it only has a few small craters from recent collisions.
04:09Miranda is the smallest of all these big moons, with a diameter of about 292 miles.
04:14NASA says it looks like it's made up of parts from different bodies, like a Frankenstein's monster.
04:19Miranda has three big features called Karoni that are unique to it.
04:24They're lightly cratered with ridges and valleys, and they're separated from older and more heavily cratered parts of Miranda by
04:31sharp boundaries.
04:32It also has giant canyons that are up to 12 times deeper than the Grand Canyon.
04:38Scientists don't know why Miranda has such different features.
04:41But one theory is that it got smashed apart by a huge collision, and then put back together, all wonky.
04:48All these big Uranian moons are stuck facing Uranus all the time, just like Earth's moon.
04:55Uranus has got some seriously dope features, but the ring system is where it's at.
04:59And get this, the ice giant's moons actually have a hand in shaping those rings.
05:04Uranus has 13 inner moons, and 13 faint rings, and they're all connected like one big cosmic family.
05:12Cordelia and Ophelia are like the guardians of the outermost ring, Epsilon.
05:16These two shepherd moons keep all the particles together, with Cordelia being the closest to Uranus's surface.
05:22But here's the kicker.
05:24There are at least eight other tiny satellites hanging around in that area, making things super crowded.
05:30NASA is still scratching their heads trying to figure out how they don't all crash into each other.
05:35The inner moons are half ice and half rock, but we don't know much about the outer ones.
05:39NASA thinks they might just be asteroids that got caught up in Uranus's gravitational pull.
05:44Either way, Uranus and its moon squad are definitely out of this world.
05:50Apparently, Uranus's moons might have salty oceans hiding under their frozen surfaces,
05:54and the farthest ones from Uranus, Titania, and Oberon could have oceans that are 30 miles deep.
06:00That's deeper than the Mariana Trench, 7 miles.
06:03But even Ariel and Umbriel might have oceans around 19 miles deep.
06:08NASA used some fancy computer modeling and revisited data from their Voyager 2 spacecraft,
06:14launched way back in 1977, to figure out the makeup and structure of these moons.
06:19They found that Titania is huge enough to keep its internal heat and prevent its ocean from freezing.
06:24But get this.
06:25The other moons might have a chance at having warm oceans, too.
06:29The researchers discovered potential sources of heat in the moon's rocky mantles
06:34that could release hot liquid and keep the oceans warm.
06:37And guess what?
06:38The oceans might even be warm enough to theoretically support life.
06:42The study also found that chlorides and ammonia are likely abundant in the oceans of these moons.
06:47Ammonia acts as antifreeze,
06:49and salts in the water could also help maintain the ocean's temperature.
06:53Now you might be thinking,
06:55how can these icy moons have liquid water?
06:58Well, turns out their internal heat and some chemicals could make it happen.
07:02For example, a study revealed that chlorides and ammonia are likely abundant in the oceans of these moons.
07:08Ammonia acts as an antifreeze,
07:10and salts in the water could also help maintain the ocean's temperature.
07:13And if these moons really do have oceans,
07:15that means there could be other ocean worlds in our solar system and beyond.
07:19But don't get too excited.
07:21These oceans are pretty salty.
07:23About 150 grams of salt for every liter of water.
07:26That may not be saltier than Utah's Great Salt Lake, but still.
07:31As for Uranus's fifth biggest moon, Miranda,
07:33whelp, it might have had an ocean at some point.
07:36But it probably froze over pretty quickly.
07:39Poor little guy.
07:40Anyway, NASA is thinking about sending a mission to Uranus
07:43to learn more about these icy giants and their moons.
07:47They're calling it the Uranus Orbiter and Probe?
07:50UOP.
07:51Sounds like a party to me.
07:53So yeah, technically there might be not four, but even five oceans.
07:57But there's still much to learn and explore.
07:59Asteroids flying around is sometimes like a fierce game of dodgeball,
08:02where you never know when some of them can go in your direction.
08:05So we can just track the situation and hope for the best.
08:09To figure out the risk scientists from different organizations
08:11have to study the positions and paths of the asteroids that come close to our planet.
08:16Especially those that are at least 0.6 miles wide.
08:20And the good news is that none of these asteroids will probably hit us
08:23for at least the next 1,000 years.
08:25Phew!
08:26To give us an idea of their power,
08:28scientists did an experiment to simulate the impact of such a gigantic asteroid.
08:33The energy released from the collision would be a mind-blowing 100,000 megatons.
08:39That's like detonating 15,000 tons of dynamite.
08:43Also, if such a big asteroid hit us,
08:45Earth would cool down significantly
08:47because of all that debris that would go into the atmosphere and block sunlight.
08:51Plants wouldn't be able to get their fuel in this case,
08:54so we'd all be in trouble, both humans and animals.
08:56Thankfully, such mammoth asteroid impacts are quite rare.
09:00The larger an asteroid, the longer it takes it to collide with Earth.
09:03For example, it's estimated that asteroids with diameters of at least 0.6 miles
09:08strike our planet about once every 700,000 years.
09:11And if we're talking about even bigger ones that are 3 miles wide,
09:14well, those are predicted to come crashing down only once every 30 million years.
09:19Yay!
09:20But hold on.
09:21Don't get too relaxed just yet.
09:23Astronomers focus on really large asteroids
09:25because those are the ones that can kind of doom our planet if they hit us.
09:29Yep, you got it right.
09:31In a dinosaur kind of way.
09:33Even if one of them didn't erase us completely,
09:36the damage would still be enormous.
09:38So, there are still some asteroids wandering around
09:41that we need to keep an eye on to see how they might evolve over time.
09:45Scientists have a model of tracking them
09:47where they focus on the parts of an asteroid's path
09:49that come close to our planet
09:51to see if the space rock poses a risk to us.
09:54And it seems there might be one asteroid,
09:587482, 1994 PC1,
10:003,600 feet in diameter that might pose some danger.
10:04It's supposed to come closer to our planet in the next 1,000 years.
10:08And when I say risky,
10:09it means there's a 0.0151% chance of it coming within one Earth-Moon distance.
10:15It already passed by us in 2022,
10:18but we were lucky because it was far enough 1.2 million miles.
10:21I'd say we can relax when it comes to asteroid scenarios.
10:25For now.
10:25Asteroids slamming into Earth would be new for humankind,
10:28but not for the planet itself.
10:30As I said, there weren't many of those big ones,
10:32but they still had enormous consequences.
10:34The first one that comes to most people's minds is, of course,
10:38the dinosaur asteroid as big as a mountain
10:40that struck our home planet around 66 million years ago
10:44near Mexico's Yucatan Peninsula.
10:46It was chaotic.
10:49Global firestorms and tsunamis were all over the place.
10:52Dust was blocking out the sun,
10:53and vaporized rock released sulfur,
10:55which then led to acid rain and the acidification of the oceans.
10:59But there was an even bigger fella that came before that one.
11:02Around 2 billion years ago,
11:04a gigantic asteroid crashed into our planet
11:06and left a massive crater in South Africa.
11:09The one we know today as the Redefort Crater.
11:11And it seems this asteroid might have been even bigger
11:14than we all originally thought.
11:16Twice as wide as the space rock that erased dinosaurs.
11:19The Redefort Crater is confirmed to be the biggest visible crater on Earth,
11:23with a diameter of about 99 miles.
11:26It used to be even bigger when it first formed, though.
11:29Maybe even 155 to 174 miles across.
11:33It's hard to figure out its true size
11:35because the crater has been eroding for the past 2 billion years.
11:38Think of it like slicing off layers from the rim of a bowl.
11:41The diameter gets smaller with each slice.
11:43When the asteroid, 7 or 5 miles wide,
11:46that wiped away dinosaurs hit Earth about 66 million years ago,
11:50it caused massive destruction.
11:52Forest fires, acid rain, tsunamis,
11:54and so much ash and dust that it changed Earth's climate.
11:58This all made about 75% of life on our planet extinct.
12:02The asteroid that created the Redefort Crater was not only bigger,
12:06but it also traveled at a higher speed.
12:09Which means the consequences there would have been even worse.
12:12But it happened a long time ago,
12:14and living beings were different back then.
12:17Maybe it was some bacteria that didn't even notice that something unusual was happening.
12:22Earth is not the only one.
12:23Lots of impacts have happened across our solar system, too.
12:26For example, in our close neighborhood.
12:29Yup, moving to Mercury and its massive crater called the Caloris Basin.
12:33It measures about 950 miles across,
12:36which is more than the state of Texas.
12:38There's a ring of towering mountains around the crater,
12:41which makes it look even more impressive.
12:43You can see different colors in the mosaic image of the Caloris Basin.
12:47They tell us more about the geology of the basin.
12:50The orange parts represent lava that once flooded the basin.
12:54These lava flows covered the original surface
12:56and added this specific orange hue.
12:59And after the lava flooded the basin on Mercury,
13:02smaller craters formed on top of the lava surface.
13:05These craters dug into the ground
13:06and uncovered the material hidden beneath the lava.
13:09Some of this material is blue in color.
13:11And this blue stuff could be a clue
13:13about what the original floor of the basin
13:14had looked like before the lava covered it.
13:17Venus, the hottest planet in our solar system,
13:20has a thick atmosphere
13:20that comes with a pretty good defense system against space rocks.
13:24It's so dense that it burns up most meteors
13:26before they even reach its surface.
13:28As a result,
13:29you won't see as many visible craters on Venus
13:32as on other rocky planets in our solar system.
13:35But Venus still has some scars
13:37that can tell us about some serious impacts that happened there.
13:40And one of the biggest scars we know about is Mead Crater.
13:43It's enormous.
13:46About 170 miles in diameter.
13:48The inner floor of this crater is relatively flat
13:51and kind of brighter than its surroundings.
13:53It's possible that the crater ended up filled
13:55with a mixture of melted rock after the impact
13:57and maybe even lava from volcanic activity on Venus.
14:02Want to get an idea of what Earth might look like
14:04without its protective layer called atmosphere?
14:08Just take a look at the moon.
14:10Its surface is littered with impact craters.
14:12This Tycho is one of the craters you'll easily notice on the moon.
14:15When you look at the full moon,
14:17you can spot it as a distinct circle
14:19with bright rays that radiate outward,
14:21slightly off-center on the lower left side of the moon.
14:24This crater, 53 miles wide,
14:26has a beautiful central peak in the middle
14:28that's topped with an intriguing boulder.
14:30The size of this boulder is impressive.
14:32It would fill about half of a typical city block here on Earth.
14:35When talking about craters,
14:37we definitely can't leave out Mars.
14:39The red planet has a much thinner atmosphere than Earth.
14:42When spacecraft approach Mars,
14:44they rely on the planet's atmosphere
14:45to slow them down as they enter it.
14:47And indeed, the atmosphere helps slow spacecraft down during landing.
14:51But it's still not thick enough
14:52to completely protect Mars
14:54from all those space rocks that are coming all the time.
14:57From July to September 2018,
14:58a dark spot appeared on the southern pole of Mars.
15:01It consists of two distinct patterns.
15:03A theory says that the bigger, lighter-colored blast pattern
15:07can be the result of an impact shockwave
15:09scouring the ice surface.
15:11The impact generated winds that spread out and scoured the ice.
15:15The inner blast pattern, which is darker in color,
15:18occurred because the impacting object
15:20managed to penetrate the thin ice layer.
15:22As it hit the surface,
15:24it sent dark sand and debris flying in all directions.
Comments