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From strange planets that defy all logic to the exact location of Earth in the vast cosmos, science is constantly revealing astonishing new truths about our universe. Explore these mind-boggling discoveries and how they challenge our understanding of space and our place within it.
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00:00This planet, yeah, the one right here, shouldn't exist, but it does.
00:04A newly discovered planet rotates around a star that's much smaller and dimmer than our sun.
00:10The planet, however, is enormous.
00:13Such a tiny star couldn't create it, so it's like finding an ostrich egg in a chicken coop.
00:20A team at Penn State built a special tool called the Habitable Zone Planet Finder.
00:25It's an instrument that's supposed to find planets around dim, cool stars.
00:30It's connected to a big telescope in Texas.
00:32The tool looks at the light from these stars, which is mostly in the near-infrared, beyond what our eyes
00:37can see.
00:38This gadget can spot changes in a star's speed caused by a planet.
00:42If the star movement slightly changes, that means there must be a gravitational pull nearby.
00:48Years ago, this technique helped find the first known exoplanet around a star like our sun.
00:53Today, we've improved this method to make more precise measurements.
00:57Our main goal is to find Earth-like planets.
01:00They should be rocky and located in habitable zones, areas around stars where liquid water could exist.
01:06The Doppler technique isn't that great at finding Earth-like worlds yet, but works well for cool, dim stars.
01:13And that's how we discovered the impossible LHS 3154b.
01:21Planets usually form in disks made of gas and dust in space.
01:25Picture a flat, spinning cloud of tiny particles.
01:28These particles come together and stick to each other, creating a flat, rotating disk.
01:33Over time, these tiny bits combine to form a solid core.
01:37This is the starting point for a planet.
01:40Once the core is there, it attracts more dust and even gas like hydrogen and helium.
01:46But making a planet this way isn't easy.
01:48They need a lot of stuff, mass, and materials.
01:52This process is called core accretion.
01:55Stars are a huge help in that process.
01:57Usually, big stars have more gravity, so they can gather more stuff to form planets.
02:02But the star we discovered recently isn't very big.
02:06It's nine times smaller than our sun.
02:08A star this small shouldn't have a big enough disk to make a heavy planet.
02:13To do that, its disk should have been at least 10 times bigger.
02:17But this heavy planet, LHS 3154b, exists.
02:23Now, this mysterious planet is 13 times heavier than our Earth.
02:27It's similar in size to Neptune.
02:29It's about 50 light-years away from us in the Hercules constellation,
02:33which, in space terms, is very close.
02:36The planet is also super close to its star, completing one year in almost four days.
02:42This discovery is making scientists rethink their ideas about how planets and stars come into existence.
02:49There are new theories coming around.
02:51For example, a theory called gravitational instability.
02:54It says that, instead of the pieces coming together bit by bit,
02:59the material in the disk collapses all at once, directly creating a planet.
03:04But even with this theory, it's hard to explain how such a heavy planet could form without a really massive
03:10disk.
03:11It'll take us some time to figure out the truth.
03:15This isn't the first planet that makes us doubt our theories.
03:19Recently, scientists found another planet called Hala.
03:22This planet is orbiting a star called Bektu.
03:25And just like the previous one, it shouldn't really exist.
03:28It's way too close to its star.
03:30Stars change a lot during their lives.
03:33Normally, when a star becomes big and prepares to leave this world,
03:36it's called the red giant stage.
03:38A star like that tends to destroy or push away any nearby planets, creating a huge mess.
03:45Hala rotates around a red giant,
03:47and it should have been swallowed or destroyed by the expanding star a long time ago.
03:52But it's still hanging there.
03:54Even though Bektu has already started burning helium and shrunk to a smaller size than expected,
04:00Hala isn't bothered in the slightest.
04:02Scientists called Hala the forbidden planet.
04:05This discovery challenges what we thought about how planets survive near aging stars.
04:11It raises two theories.
04:13One suggests that Bektu was once two stars, a white dwarf and a red giant.
04:19Hala orbited them both, and they merged before the red giant fully expanded.
04:23This allowed Hala to survive, because the extra helium from the white dwarf
04:28prevented the red giant from growing too much.
04:30The second theory says that Hala formed from the debris created when the two stars merged.
04:36In this scenario, Hala would be a very young planet orbiting an elderly star.
04:41Astronomers plan to continue studying Hala and look for more planets like that.
04:48Another oddball, besides me, is called LTT 9779b.
04:54This one scares us too, because it's too shiny.
04:57The planet reflects 80% of the light from its star.
05:01Regular mirrors reflect from 85 to almost 100% of light,
05:05which means that this mysterious planet should look like a rough mirror,
05:09with aluminum or silver-like reflections.
05:12This is another Neptune-sized planet.
05:15It's located 268 light-years from us,
05:18and was discovered by NASA's TESS spacecraft.
05:20It completes a full rotation around its star in just 19 hours.
05:25It's so close to its star that it's scorching high,
05:28reaching temperatures over 3,600 degrees Fahrenheit.
05:32Normally, planets this close lose their atmosphere and turn into bare rocks.
05:37But this one breaks the rules again.
05:41Now this time, we know the secret of its survival.
05:45It's because of the planet's shiny metallic clouds,
05:48which are made of glass and titanium salt.
05:50These clouds rain titanium onto its hot surface.
05:54They also reflect a lot of the light,
05:56preventing the planet from getting too hot and losing its atmosphere.
06:00It's like having a mirror shield.
06:02This planet's size also surprised scientists.
06:05It's way bigger than Earth.
06:06Other planets this close to their stars
06:09are either much bigger gas giants or small rocky planets.
06:13This planet is a smaller gas giant,
06:15and scientists didn't expect it to exist so close to its star.
06:19This is the shiniest planet ever found,
06:22even shinier than Venus.
06:24But despite its cool appearance,
06:26it's probably not a friendly place for life
06:28because of its extreme temperatures and strange metallic rain.
06:35And our final rule-breaker is a planet called WASP-107b.
06:40Scientists discovered it using the James Webb Space Telescope.
06:44It's located around 208 light-years from us in the Virgo constellation.
06:49It's also fast and completes an orbit around its star in just six days.
06:54This is a super-Neptune exoplanet.
06:57It's similar to Jupiter in some ways,
06:59including the same size and scorching hot temperatures.
07:02But the main difference is that it's much lighter, weaker, and less dense.
07:07This is the least dense planet we've discovered so far.
07:10After researching some more, we also found that it has a tail.
07:14The helium on the planet extends beyond the transit egress.
07:18The planet is slowly losing its atmosphere
07:21due to extreme ultraviolet radiation from the star.
07:24This creates a comet-like tail.
07:26So, it looks like a fluffy comet.
07:31But that was just the beginning.
07:33The planet's low density, or fluffiness,
07:36allowed astronomers to study its atmosphere in detail.
07:39They found some surprising things,
07:42like water vapor and clouds made of fine silicate particles,
07:46which are like really fine-grained sand.
07:48The planet's host star doesn't emit a lot of high-energy light.
07:52But since WASP-107b is so loose,
07:56the light can penetrate deep into its atmosphere.
07:58This creates sulfur dioxide,
08:01that smell when you light a match.
08:03In other words,
08:04it's a fluffy planet that rains sand and smells like matches.
08:07The researchers think the sand clouds in the atmosphere
08:10form in a similar way to clouds on Earth.
08:13They just have droplets of sand instead of water.
08:16The sand droplets condense, fall,
08:19turn into silicate vapor in hot layers within the planet,
08:22and then rise again to form clouds once more.
08:25And, once again,
08:26this planet couldn't have formed in its current spot.
08:30Astronomers say that it likely moved closer to its star
08:32from a birth orbit,
08:34because it was attracted by some heavier neighbor.
08:36It also follows a retrograde orbit,
08:39meaning it orbits in the opposite direction to its star's rotation.
08:43All these discoveries are changing how we understand planets and their atmospheres,
08:48giving us new insights into the mysteries of our own solar system.
08:56A long time ago,
08:58we believed that the entire universe revolved around our own little blue planet.
09:02It's called a geocentric model.
09:04We thought that the sun, the stars,
09:07and all those twinkling celestial bodies all danced around us.
09:11This theory was super popular in ancient Greece and Rome.
09:14Famous geniuses like Aristotle and Ptolemy really loved this idea.
09:19Why did people believe this in the first place?
09:22Well, first of all, we have a massive ego.
09:25Second of all, there were a couple of things that seemed to support it.
09:28For example, if you stand on Earth and look up at the sun,
09:31it seems like the sun is spinning around us once every day.
09:34The moon and the planet seem to be doing the same thing.
09:36The obvious conclusion is,
09:38oh, they're probably twirling around the Earth.
09:48Then there's the fact that Earth feels pretty steady when you're standing on it.
09:52It just doesn't feel like it's moving, you know?
09:54And because of the stability beneath our feet,
09:57people thought that the Earth was unmoving.
09:59But even back then, there were ancient Greek and Roman philosophers that were onto something cooler.
10:05They paired the geocentric model with the idea that Earth was actually a round ball floating in space,
10:11not a flat disk.
10:12They started connecting the dots.
10:14And after a while, astronomer and mathematician Aristarchus of Samos had a game-changing idea.
10:20He thought that the Earth might not be the center of everything.
10:23He proposed that everything revolved around the sun.
10:27Funny to think that back in the days, this idea was considered insane.
10:37That's why for a while, most people stuck to their geocentric views.
10:42It took us many centuries to finally accept the heliocentric model,
10:46where all the planets in our solar system revolve around the sun.
10:49This idea was brought to life by people like Copernicus, Galileo, and Kepler.
10:54This change wasn't easy for people.
10:56It was hard to let go of our space crown.
10:59But gradually, we came to terms with it.
11:02And by letting go of this idea, we discovered a whole new world.
11:07This journey led us to an astonishing realization.
11:10Not only we're not the center of the universe, we're nothing but a little speck in it.
11:15We're a microscopic dot, sprawling galaxy called the Milky Way.
11:20The discovery of the Milky Way started right from our own backyards.
11:25If you've ever gazed up at the stars on a clear night,
11:28you might have noticed a faint, luminescent band stretching.
11:32It's like a shimmering celestial ribbon woven with stars.
11:36That is our galaxy.
11:39It was named Milky Way because it looks like someone spilled milk on a road.
11:52It was perfectly depicted in the 90s by Voyager 1.
11:56NASA's spacecraft took a picture called the Pale Blue Dot.
12:00That tiny little pixel that's almost impossible to see is our planet.
12:05The photo was taken from a chilling 3.7 billion miles away from the sun.
12:09On a universe scale, this distance is nothing.
12:13But for us, it's unimaginable.
12:15So when scientists discovered the Milky Way, they armed themselves with telescopes.
12:20Their goal was to map the uncharted territories of the night sky.
12:24And of course, to find our place in this gigantic world.
12:28To do that, first, we had to unlock the secrets of our galaxy's structure.
12:34Okay, so we can clearly see that it has some band-like formation.
12:39That probably means that our galaxy is not a big, round ball like the planets and stars.
12:45In reality, it's more like a giant pancake.
12:48A flattened disk.
12:50And we can see that we're not above it, and not below it.
12:54We're right on the plate.
13:03The next step is to travel across the Milky Way to map it.
13:07There's a little problem, though.
13:08To do that, we'd have to traverse thousands of light-years perpendicular to this pancake-like plane.
13:14Just to put things in perspective, think of Voyager 1.
13:18The one that took the pale blue dot picture.
13:22That spacecraft has been journeying through space for almost half a century.
13:26It left the solar system years ago.
13:29You know how many light-years it traveled?
13:300.002.
13:33And how many light-years is the Milky Way?
13:35100,000.
13:36You get the picture.
13:38But the lack of fancy technology didn't stop us.
13:42In the 18th century, a bold astronomer named William Herschel decided to explore our galaxy.
13:48With nothing but a telescope, this Indiana Jones of astronomy started mapping the stars in the night sky.
13:53As a result, he discovered Uranus, more than 2,000 nebulas,
13:58and created the first map of the Milky Way that depicted it as a disk.
14:02The map wasn't super accurate, but still very impressive.
14:16It's like space fog that can block our view of stars in the center of the Milky Way.
14:21This dust made the central region of the Milky Way appear less crowded than it actually is.
14:26Now, let's go all the way to the 20th century.
14:30Henrietta Swan-Levitt, an American astronomer, was another curious stargazer.
14:35But she focused her attention on a special kind of star called Cepheid variables.
14:40These stars had a unique quirk.
14:42They pulsed, getting brighter and dimmer in a predictable pattern.
14:47Levit's job at the observatory was like being a librarian.
14:50She cataloged these special stars.
14:52And in doing so, she stumbled upon something incredible.
14:58A direct link between the brightness of these stars and the rate of their pulsations.
15:03This discovery is now known as Levit's law.
15:07It meant that by simply measuring how quickly these stars pulsed,
15:12astronomers could figure out how far away they were.
15:14These pulsating stars became the rulers for measuring distances.
15:26Before the 1920s, most scientists believed that our Milky Way was the only galaxy in the universe.
15:33But as telescopes improved, some astronomers started realizing that this isn't the case.
15:39We started finding more and more galaxies.
15:42But if the Milky Way was just one of many galaxies, where exactly were we within it?
15:48Meet the scientist named Harlow Shapley.
15:51Armed with a powerful telescope, Shapley turned his attention to globular clusters.
15:55These are tightly packed groups of ancient stars that gather together in spherical shapes.
16:01That's when he noticed something interesting.
16:03The oldest stars around us weren't scattered all over the canvas.
16:07They were clustered around the center of the Milky Way.
16:10And they were pointing in the direction of certain constellations like Sagittarius and Scorpius.
16:20It turns out that the origin of our galaxy began from the center.
16:25It was the heart of the Milky Way, and the most ancient guys were hanging out there.
16:30Which means we're not even at the center of our own galaxy.
16:35Seems like our importance becomes less and less with each new discovery, huh?
16:41Anyway, Shapley found out that we were positioned somewhere on the outskirts of our galaxy.
16:46Shapley's calculations weren't perfectly accurate, but he got pretty close.
16:51Luckily, now we have very precise and cool tools.
16:54Since then, we've since pinpointed our precise location.
16:58We're located near a partial arm of the Milky Way called the Orion Arm.
17:02It's about 26,000 light-years from the heart of our galaxy.
17:06And that was the story of how we found out where we are in the Milky Way.
17:16You think our story is over?
17:18Oh, absolutely not.
17:20Meet Gaia, the European Space Agency's celestial cartographer.
17:25Launched in 2013, Gaia embarked on a daring mission.
17:30It has to map the Milky Way in unprecedented detail.
17:33Not just some rough map, but a photographer capturing every nuance of our galaxy.
17:38Gaia is piecing together the positions and motions of about 1 billion stars.
17:43And it's like 1% of the stars in the Milky Way.
17:46But even that tiny fraction is enough to create a masterpiece of cosmic cartography.
17:52What a grand journey it was.
17:54It led us from thinking Earth was the center of the universe
17:58to realizing we're less than a speck in the grand scheme of things.
18:01But what's more important is that this story shows humanity's drive to uncover the mysteries of the world.
18:08And there's always something new to explore.
18:12Discoveries just keep coming, so stay tuned and keep looking at the night sky.
18:16Bye.
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