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From the first light of the universe to a planet that defies physics, astronomers are uncovering cosmic mysteries beyond imagination. Are we ready for what space has to reveal?
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00:00Right after its creation, the cosmos was shrouded in darkness.
00:04I mean, I wasn't there, but that's what most scientists are thinking.
00:07All of the stars were hidden behind a thick cloud of primordial gases.
00:11Then, all of a sudden, something cleared up this fog,
00:15and the universe started shining as it finally woke up.
00:18But how did this happen?
00:20Eight faint, recently discovered galaxies might hold the answer.
00:25The Big Bang created our world around 13.8 billion years ago.
00:30At first, it was just a super-hot and chaotic boiling soup of particles.
00:35But over time, things cooled down, and particles could finally stick to each other.
00:40That's how the atoms appeared.
00:42Some helium, but mostly hydrogen, the very first element.
00:46And these first elements started creating thick gas clouds, which were very opaque.
00:51Then, the first stars started forming.
00:54They were incredibly bright, emitting lots of light, including ultraviolet radiation.
01:00But even though these stars were shining,
01:02much of their light couldn't travel far because of that nasty hydrogen fog.
01:06The gas clouds absorbed and scattered any little light particles around.
01:11It was like the light was trapped around the stars.
01:14The dark ages lasted for hundreds of millions of years.
01:17Then, everything changed.
01:20Recently, the James Webb Space Telescope has spotted ancient dwarf galaxies from that epoch.
01:26Turns out, they're the ones we should be thanking for lighting up the universe.
01:31Back then, they were filled with early stars.
01:33These stars emitted tons of radiation that was so powerful that it managed not to just overcome,
01:40but break apart the hydrogen atoms in the fog.
01:43It turned them into charged particles, like particles that carry a little bit of electricity, called ions.
01:49Little by little, the fog was cleared away.
01:52This process of clearing out the fog is called re-ionization.
01:56And this beautiful time is known as the epoch of re-ionization.
02:00Finally, the light was able to travel to all corners of the universe, which was a game-changer,
02:06just like humans' Age of Enlightenment.
02:10To find these little igniters, astronomers used a technique called gravitational lensing.
02:16Imagine light traveling through space like a straight beam.
02:19But just like everything in our world, even time, light obeys gravity.
02:24If it's too strong, it'll literally bend the light beams.
02:28So when the beams pass near a massive object, the object's gravity pulls on them, curling and twisting their path.
02:35That's why black holes look so creepy, as they stretch stars and space around them like some whirlpools.
02:41But it's not that creepy.
02:43A regular glass or magnifying glass does something similar.
02:47Hence the name gravitational lensing.
02:51When the lensing object is horrifyingly massive, it bends the light into multiple images of the same object,
02:58creating a creepy and mesmerizing structure called an Einstein ring.
03:03But if it's not that big, then the bending is less dramatic.
03:07And it just slightly distorts the shape of the background object, making it look kinda stretched.
03:14Gravitational lensing also helps scientists study things like the spooky dark matter.
03:19If the light looks stretched, and it's not just because of some obvious mass of objects nearby,
03:25then it might be something invisible and heavy bending it.
03:29Since these eight galaxies were too faint,
03:32no wonder they're almost as old as my unread emails.
03:36Scientists had to use these gravity tricks to observe them.
03:39The team studied light from galaxies that are over 13 billion years old.
03:44Finally, they focused on a galaxy cluster called Abel 2744, also known as Pandora's Cluster.
03:51And these findings helped them understand how even little fellas played a huge role in transforming the early universe.
03:59The James Webb Telescope is an incredible tool.
04:02And soon, it might help us look at even earlier times, at the cosmic dawn,
04:07when the universe was only several millions of years old.
04:11Another great tool, called the Roman Space Telescope, is going to help it.
04:15It's also possible that these galaxies weren't the only helpers in this entire saga.
04:21These early massive stars were absolutely terrifying.
04:24They just don't make them like that anymore.
04:26Some estimates suggest they were 30 to 300 times more massive than our Sun,
04:31and millions of times brighter.
04:34Modern stars have some heavier elements in them.
04:37But back then, they used only the stuff available, hydrogen and helium,
04:41which is why they were so hot and shiny.
04:43But they also had very short lifespans, lasting just a few million years.
04:48For example, our Sun is 4.6 billion years old and is still going strong, thankfully.
04:55At the end of their lives, they went supernova.
04:57These colorful bursts of energy were so strong that they forged the first heavier elements in our world
05:04and spread them across the universe, planting first seeds for the future planets.
05:09Meanwhile, the stars themselves didn't just disappear.
05:13They collapsed under their own gravity, creating the first black holes.
05:18Now, the black holes are also known for producing insane amounts of radiation.
05:22So, it's possible that they might have helped speed up the clearing of the fog.
05:28Ironically, they helped the universe shine brighter while sucking up the light at the same time.
05:33Recent discoveries show that black holes might be much, much older than we used to believe.
05:38They probably helped new stars and galaxies form.
05:41They were millions or even billions of times the mass of the Sun.
05:46The James Webb Telescope has already found a pair of early quasars.
05:50That's what we call the bright centers of galaxies, powered by supermassive black holes.
05:55It's a curious pair of quasars that are merging, just 900 million years after the Big Bang.
06:02This might be the earliest and most distant pair of merging quasars ever found.
06:07The telescope has also been studying things that are called cosmic lighthouses.
06:12In scientific language, they're pulsars.
06:15Pulsars are superdense remnants of massive stars.
06:18They form from stars that were once 4 to 8 times more massive than our Sun.
06:24One of the greatest things about them is how fast they spin.
06:28They're one of the fastest objects in the universe.
06:30They might do around 700 rotations in just one second.
06:34They got their name because they behave like lighthouses, basically flickering radio waves.
06:40These beams of radiation sweep across the sky, creating a pulse-like signal that we detect.
06:47Now, a star basically works like this.
06:49There's nuclear fusion happening inside of its core.
06:53Atoms get fused in each other, move at crazy speeds, bump, all meanwhile releasing an unbelievable amount of energy.
07:01That's why they emit tons of light and heat.
07:04Of course, all this pressure tries to push outward, sweating like crazy to expand a star.
07:10The greatest the fusion is, the more powerful and insane the star gets.
07:14On the other hand, there's gravity that's pulling inward, trying to compress the star and keep it a nice small
07:20dense ball.
07:22As long as there's balance, the star keeps living.
07:25But when it gets old and spends all of its nuclear fuel, it becomes too weak to generate the energy
07:31it needs and can't fight against gravity anymore.
07:34That's when it basically collapses under its own weight, going supernova.
07:39What's left behind is the star's core.
07:42But now, it's crushed down to an incredibly small size, about 12 to 17 miles across.
07:49It's roughly the size of a city.
07:51This dense core is known as a neutron star.
07:55The material in a neutron star is so dense that just a teaspoon of it would weigh as much as
08:014 billion tons, like 10,000 Empire State Buildings.
08:05And all this collapse sets off a trigger, causing the neutron star to spin super fast, creating a pulsar.
08:12It's kind of like when an ice skater spins faster when they pull their arms in.
08:17Pulsars often have a smaller star friend orbiting them.
08:21Although it's not always a friendly relationship.
08:23Not long ago, astronomers discovered a pulsar that was surrounded by lots of energetic material for some reason.
08:30They realized that all this material was the remnants of another much larger star.
08:35Turns out, the pulsar had been slowly destroying its friend with its terrifying radiation and particles,
08:42until it basically ate the neighbor away.
08:45It's similar to how a black widow spider consumes its mate.
08:48So, systems like this were called black widow pulsars.
08:52In any case, these lighthouses most likely helped the re-ionization process as well.
08:58A long time ago, they could be very energetic stars in small galaxies,
09:03and could emit enough radiation to transform the early universe.
09:07The James Webb Telescope's mission is to find more of these lighthouses,
09:11and see what role they played in the universe's evolution.
09:16From planets with glass rain and oceans of lava,
09:20to worlds with three suns and giant diamonds,
09:23our universe is full of surprises.
09:27Sometimes we find celestial bodies that shouldn't even exist at all.
09:31But despite all logical reasoning, they live and thrive.
09:37In 2023, we discovered another impossible planet,
09:43TOI-5295b.
09:45Once again, our universe turns out to be much more complicated than we thought,
09:49and this isn't the only strange planet that we've discovered in recent years.
09:55So, let's take a look at a couple of these impossible planets.
10:02TOI-5205b is the first one on the list.
10:05This is an unusually large planet orbiting a small star.
10:10It's located about 280 light-years from Earth.
10:14It's quadrillions of miles, but on a cosmic scale, it's pretty close.
10:19This planet was discovered just recently, in 2023.
10:23So why is it so special?
10:25Because it doesn't follow the rules of planetary formation,
10:29like other planets in its neighborhood.
10:32TOI-5205b is a bit of a rebel
10:35because it orbits a tiny red dwarf star
10:37that's only four times larger than Jupiter.
10:41What's so weird about it, you ask?
10:43Well, you see, a red dwarf is basically like
10:46the runt of the litter in the world of stars.
10:49This type of star is rather cold,
10:52about two times colder than the sun.
10:55They have a reddish tint, hence the name.
10:58And yep, stars work quite strangely.
11:01The closer they are to red, the colder they are.
11:04And the closer to blue, the hotter they are.
11:06Hey, I don't make the rules.
11:10Anyway, because of all this, they aren't very bright.
11:13So without a good telescope, you won't see them in the sky.
11:17But they aren't just some space losers.
11:20They're the most common stars in the universe.
11:23They also live much longer than our sun.
11:26And thanks to this, they usually have a bunch of different planets orbiting them,
11:30including those similar to our Earth.
11:34So if one day we decide to find a new home,
11:37it may well be near some red dwarf.
11:41But here's the catch with TOI-5205b.
11:45It's a gas giant.
11:47Gas giants like, for example, Jupiter or Saturn,
11:50are the behemoths of the universe.
11:52These planets are mainly made up of gases like hydrogen and helium.
11:57They don't have a solid surface like Earth or Mars.
12:00So you can't exactly land on them without getting crushed by the immense pressure.
12:05And they're not called giants for nothing.
12:08They're absolutely massive.
12:11In fact, if you took all the other planets in our solar system and squished them together,
12:16they still wouldn't be as big as Jupiter.
12:18In other words, they're the gassy wrestlers of the planetary family.
12:24So, how is it possible that such a huge planet orbits such a small, weak star?
12:30Red dwarfs are usually considered too small to host gas giants.
12:34Moreover, it's physically impossible.
12:37Or at least, so we thought.
12:39But TOI-5205b had other plans and decided to form near a red dwarf anyway.
12:47It's like a small pea orbiting around a lemon,
12:50which doesn't sound that bad until you remember that Jupiter next to our Sun
12:54is like a pea next to a basketball.
12:57Only really big stars are able to keep such big planets nearby.
13:02This had astronomers scratching their heads
13:05as it went against everything they thought they knew about planet formation.
13:09And while we try to figure out how TOI-5205b managed to break the rules,
13:15the planet itself seems pretty content to blaze its path through the cosmos.
13:21And it isn't the only one.
13:23In recent years, scientists have discovered a bunch of such forbidden planets.
13:28So let's check out the other ones.
13:30Imagine a giant planet that's so soft and fluffy,
13:42it's like a marshmallow floating in space.
13:45That's right.
13:46TOI-3757b is a gas giant that's been dubbed the marshmallow planet
13:52because of its incredibly low density.
13:55Of course, it's not edible and cute like real marshmallows,
13:59but it would still be fun to touch it.
14:01This planet was discovered in 2022.
14:05It's located in the constellation of Uriga the Charioteer,
14:10591 light-years from us.
14:13Just like the previous one, it's also orbiting around a red dwarf star.
14:17And get this, TOI-3757b only takes around three days to complete one orbit.
14:25Imagine having a birthday every three days.
14:29It's also incredibly close to its star, just some 3.5 million miles away.
14:35For comparison, the distance between the Sun and the planet closest to it, Mercury,
14:40is about 36 million miles.
14:42So TOI-3757b is like right on top of its star.
14:47Let's hope this marshmallow planet doesn't get too toasted.
14:51Now, let's talk about how this planet was discovered.
14:55It was spotted by the Transiting Exoplanet Survey Satellite, or TESS,
15:00a space detective on the hunt for new planets.
15:03The transit detection method is when scientists use the star's light to find their planets.
15:09When the planet passes through the star,
15:11it blocks a tiny portion of the star's light,
15:13making it look a little dimmer for a while.
15:16Scientists can detect this dip in brightness using special instruments.
15:20If the dip happens regularly, they can tell that there's a planet orbiting the star.
15:26The size of the dip in brightness tells scientists how big the planet is,
15:30and how close it is to the star.
15:33If the dip is really small, that means the planet is probably pretty small too.
15:37And if the dip happens more frequently,
15:40that means the planet is probably closer to the star.
15:43And this is how we discovered our marshmallow planet, and many other ones.
15:49Overall, TOI-3757b is a fascinating planet that's captured our imaginations with its unique properties.
15:58Now, let's move on to the next mysterious celestial body.
16:04TYC 8998-760-1b, on the border of a planet and a star.
16:10Phew, that was a mouthful.
16:12Let me introduce you to a planet whose name I won't repeat.
16:15Well, this baby is also a gas giant.
16:19But not just any gas giant.
16:21In fact, it's so big, it could make Jupiter feel like a tiny pebble in comparison.
16:27I mean, it's 14 times the mass of Jupiter and 3 times as big around.
16:32Isn't that impressive?
16:34It orbits a very young, sun-like star 300 light-years away.
16:39This star is only 17 million years old, and yes, it's considered a baby among the stars.
16:46For comparison, our own sun is about 4.5 billion years old.
16:52But the star itself isn't that interesting.
16:55The planet, on the other hand, is a bit of a weirdo.
16:57You see, planets just can't be that big.
17:00With its enormous mass, it should be a star.
17:04It's kind of like the Caspian Sea, which is considered the largest lake in the world.
17:09Just as the Caspian Sea isn't really a sea or a lake, this planet is the middle child of the
17:14universe.
17:15Not quite a star, but not exactly a planet either.
17:19Some scientists think that it might be a failed star, which is like saying a cake that didn't rise properly.
17:26And let's talk about its temperature.
17:28You know how you feel like a baked potato when it's 90 degrees Fahrenheit outside?
17:33Well, this planet laughs at us.
17:35Its estimated surface temperature is a whopping 2,600 degrees Fahrenheit.
17:41That's hotter than a jalapeno popper straight out of the fryer.
17:45This time, the planet was discovered by the imaging detection method.
17:49You see, capturing pictures of exoplanets is no easy feat.
17:54The star is always way brighter and ruins the pic.
17:58It's like trying to take a selfie with your crush while your annoying little sibling is jumping up and down
18:02in front of you.
18:03But scientists have a solution.
18:06They use some specialized optics and clever observation methods, like coronography.
18:11They basically block out the light of a star so that we can see the planet more clearly.
18:16Magic, right?
18:18And that's how they discovered this not-a-star planet, too.
18:22And now, it's giving scientists a lot to think about.
18:25It makes us question what we know about the formation of planets.
18:29Let's hope we'll find out more about it in the future.
18:32It's amazing to think about the weird and wacky things that exist in our universe, and these planets definitely fit
18:38the bill.
18:38Who knows what else is out there waiting to be discovered?
18:42Maybe someday we'll find a planet that's even more impossible than the ones we just discussed.
18:47Until then, keep your eyes on the skies and your mind open to the infinite possibilities of our universe.
18:53We'll see you next time.
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