How We Know Earth’s Exact Spot in the Universe

Bright Side

We know Earth’s exact spot in the universe thanks to a mix of astronomy and technology. First, we figured out we’re the third planet orbiting the Sun, which is part of the Milky Way galaxy—a giant spiral of stars. Then, astronomers mapped out the Milky Way itself, realizing it’s in a smaller arm of the galaxy called the Orion Arm. Beyond that, we know the Milky Way is part of a group of galaxies called the Local Group, which is in an even bigger structure called the Virgo Supercluster. Using telescopes and satellites, scientists also track Earth’s position relative to other stars, galaxies, and cosmic landmarks like quasars. But can we be sure we're right about the position of our Earth?  #brightside   Animation is created by Bright Side.  ---------------------------------------------------------------------------------------- Music from TheSoul Sound: https://thesoul-sound.com/   Listen to Bright Side on:  Spotify - https://open.spotify.com/show/0hUkPxD34jRLrMrJux4VxV Apple Podcast - https://podcasts.apple.com/podcast/idhttps-podcasts-apple-com-podcast-bright-side/id1554898078 ---------------------------------------------------------------------------------------- Our Social Media: Facebook - https://www.facebook.com/brightside/ Instagram - https://www.instagram.com/brightside.official/ Tik Tok - https://www.tiktok.com/@brightside.official?lang=en Snapchat - https://www.snapchat.com/p/c6a1e38a-bff1-4a40-9731-2c8234ccb19f/1866144599336960  Stock materials (photos, footages and other):  https://www.depositphotos.com  https://www.shutterstock.com  https://www.eastnews.ru  ---------------------------------------------------------------------------------------- For more videos and articles visit: http://www.brightside.me

Transcript

00:00A long time ago, we believed that the entire universe revolved around our own little blue

00:08planet. It's called a geocentric model. We thought that the sun, the stars, and all those

00:14twinkling celestial bodies all danced around us. This theory was super popular in ancient

00:20Greece and Rome. Famous geniuses like Aristotle and Ptolemy really loved this idea. Why did

00:26people believe this in the first place? Well, first of all, we have a massive ego. Second

00:32of all, there were a couple of things that seemed to support it. For example, if you

00:36stand on Earth and look up at the sun, it seems like the sun is spinning around us once

00:40every day. The moon and the planet seem to be doing the same thing. The obvious conclusion

00:44is, oh, they're probably twirling around the Earth.

00:55Then there's the fact that Earth feels pretty steady when you're standing on it. It just

00:59doesn't feel like it's moving, you know? And because of the stability beneath our feet,

01:03people thought that the Earth was unmoving. But even back then, there were ancient Greek

01:08and Roman philosophers that were onto something cooler. They paired the geocentric model with

01:13the idea that Earth was actually a round ball floating in space, not a flat disk. They started

01:19connecting the dots. And after a while, astronomer and mathematician Aristarchus of Samos had

01:25a game-changing idea. He thought that the Earth might not be the center of everything.

01:30He proposed that everything revolved around the sun. Funny to think that back in the days,

01:36this idea was considered insane.

01:44That's why for a while, most people stuck to their geocentric views. It took us many

01:49centuries to finally accept the heliocentric model, where all the planets in our solar

01:53system revolve around the sun. This idea was brought to life by people like Copernicus,

01:58Galileo, and Kepler. This change wasn't easy for people. It was hard to let go of our space

02:05crown. But gradually, we came to terms with it. And by letting go of this idea, we discovered

02:12a whole new world. This journey led us to an astonishing realization. Not only we're

02:18not the center of the universe, we're nothing but a little speck in it. We're a microscopic

02:23dot, sprawling galaxy called the Milky Way. The discovery of the Milky Way started right

02:29from our own backyards. If you've ever gazed up at the stars on a clear night, you might

02:35have noticed a faint luminescent band stretching. It's like a shimmering celestial ribbon woven

02:41with stars. That is our galaxy. It was named Milky Way because it looks like someone spilled

02:48milk on a road. It was perfectly depicted in the 90s by Voyager 1. NASA's spacecraft

03:04took a picture called the Pale Blue Dot. That tiny little pixel that's almost impossible

03:09to see is our planet. The photo was taken from a chilling 3.7 billion miles away from

03:15the sun. On a universe scale, this distance is nothing. But for us, it's unimaginable.

03:22So when scientists discovered the Milky Way, they armed themselves with telescopes. Their

03:27goal was to map the uncharted territories of the night sky. And of course, to find our

03:32place in this gigantic world. To do that, first, we had to unlock the secrets of our

03:39galaxy's structure. Okay, so we can clearly see that it has some band-like formation.

03:45That probably means that our galaxy is not a big round ball, like the planets and stars.

03:51In reality, it's more like a giant pancake. A flattened disk. And we can see that we're

03:58not above it, and not below it. We're right on the plate.

04:10The next step is to travel across the Milky Way to map it. There's a little problem, though.

04:15To do that, we'd have to traverse thousands of light years perpendicular to this pancake-like

04:20plane. Just to put things in perspective, think of Voyager 1, the one that took the

04:26Pale Blue Dot picture. That spacecraft has been journeying through space for almost half

04:31a century. It left the solar system years ago. You know how many light years it traveled?

04:39Two. And how many light years is the Milky Way? 100,000. You get the picture. But the

04:45lack of fancy technology didn't stop us. In the 18th century, a bold astronomer named

04:51William Herschel decided to explore our galaxy. With nothing but a telescope, this Indiana

04:57Jones of astronomy started mapping the stars in the night sky. As a result, he discovered

05:02Uranus, more than 2,000 nebulas, and created the first map of the Milky Way that depicted

05:07it as a disk. The map wasn't super accurate, but still very impressive.

05:18Unfortunately, he didn't know about something called interstellar dust. It's like space

05:24fog that can block our view of stars in the center of the Milky Way. This dust made the

05:28central region of the Milky Way appear less crowded than it actually is. Now, let's go

05:34all the way to the 20th century. Henrietta Swan Leavitt, an American astronomer, was

05:39another curious stargazer. But she focused her attention on a special kind of star called

05:44Cepheid variables. These stars had a unique quirk. They pulsed, getting brighter and dimmer

05:51in a predictable pattern. Leavitt's job at the observatory was like being a librarian.

05:57She cataloged these special stars. And in doing so, she stumbled upon something incredible.

06:05A direct link between the brightness of these stars and the rate of their pulsations. This

06:10discovery is now known as Leavitt's Law. It meant that by simply measuring how quickly

06:16these stars pulsed, astronomers could figure out how far away they were. These pulsating

06:22stars became the rulers for measuring distances.

06:30Before the 1920s, most scientists believed that our Milky Way was the only galaxy in

06:38the universe. But as telescopes improved, some astronomers started realizing that this

06:44isn't the case. We started finding more and more galaxies. But if the Milky Way was just

06:51one of many galaxies, where exactly were we within it? Meet the scientist named Harlow

06:56Shapley. Armed with a powerful telescope, Shapley turned his attention to globular clusters.

07:02These are tightly packed groups of ancient stars that gather together in spherical shapes.

07:08That's when he noticed something interesting. The oldest stars around us weren't scattered

07:12all over the canvas. They were clustered around the center of the Milky Way. And they were

07:17pointing in the direction of certain constellations like Sagittarius and Scorpius.

07:27It turns out that the origin of our galaxy began from the center. It was the heart of

07:33the Milky Way, and the most ancient guys were hanging out there, which means we're not even

07:38at the center of our own galaxy. It seems like our importance becomes less and less

07:44with each new discovery, huh? Anyway, Shapley found out that we were positioned somewhere

07:51on the outskirts of our galaxy. Shapley's calculations weren't perfectly accurate, but

07:56he got pretty close. Luckily, now we have very precise and cool tools. Since then, we've

08:02since pinpointed our precise location. We're located near a partial arm of the Milky Way

08:07called the Orion Arm. It's about 26,000 light-years from the heart of our galaxy. And that was

08:14the story of how we found out where we are in the Milky Way.

08:21You think our story is over? Oh, absolutely not. Meet Gaia, the European Space Agency's

08:30celestial cartographer. Launched in 2013, Gaia embarked on a daring mission. It has

08:37to map the Milky Way in unprecedented detail. Not just some rough map, but a photographer

08:42capturing every nuance of our galaxy. Gaia is piecing together the positions and motions

08:48of about 1 billion stars, and it's like 1% of the stars in the Milky Way. But even that

08:54tiny fraction is enough to create a masterpiece of cosmic cartography. What a grand journey

09:00it was. It led us from thinking Earth was the center of the universe to realizing we're

09:05less than a speck in the grand scheme of things. But what's more important is that this story

09:11shows humanity's drive to uncover the mysteries of the world. And there's always something

09:16new to explore. Discoveries just keep coming, so stay tuned and keep looking at the night sky.

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