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You know how it all started 13.8 billion years ago with a big bang?
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No, no, wait, I can do better.
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Now, let's never mind.
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And the universe has been expanding ever since.
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At its young age, it was all made of gas, huh?
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Mostly helium and hydrogen.
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For billions of years, the gas has expanded and cooled down.
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Meanwhile, Galaxy stars another mysterious thing in space
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we try to explore today, formed because of gravitational forces.
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And in that chaos, thus like in middle school, about 4.6 billion years ago,
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our magnificent planet was born too.
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It all started as a disc of gas and dust that orbited the young sun,
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just the same way it was with the rest of the planets in our solar system.
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This disc consisted of dust particles of different sizes and gas.
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They were circling the sun at different speeds and in orbits that weren't stable and predictable.
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They were bumping into each other all the time.
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These particles grew from very small grains of dust into boulders,
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then later into bigger objects called planetesimals,
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that had a range from miles to hundreds of miles in diameter.
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And these planetesimals that were orbiting the sun within the disc
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had gravitational force strong enough to pull other objects from the neighborhood
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out of their orbits and collide with them.
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As they were constantly hitting each other, they got bigger and bigger
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until some got to the size of thousands of miles in diameter.
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That's nearly the size of Mars and the Moon.
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We know these things because of meteorites.
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They come from different places all over our solar system
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and bring all kinds of materials to our planet,
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giving us something cool to study and learn about our solar system and how it formed.
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These materials include very small pieces of dust and rock
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that have gone through the chaos and survived those rough times,
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even before the planets were created.
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Meteorites also brought pieces of asteroids and planetesimals left behind
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after the planet forming process ended.
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As these objects were forming,
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some radioactive elements were left trapped inside the minerals that, again,
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That's how scientists could tell how old they were.
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But the final stage of Earth's formation and generally this whole chaos
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that was happening in our solar system may have taken a little bit longer,
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possibly even up to 100 million years more.
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That's when the last enormous impact was and the Earth finally reached its full size.
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What actually happened is that it hit another object
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which was nearly as large as Mars.
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This collision was so strong that the impact produced enough energy
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to vaporize some of the metal and rock both from the Earth and the Mars-sized object.
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And this vapor created a disk that was surrounding our planet.
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That disk cooled and clumped together at some point,
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which is when we got our moon.
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Our moon was the result of impact debris,
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which was a combination of hot gas and molten rock.
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There are some theories of how the moon formed though.
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One claims it broke off from the Earth.
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Another one says the moon formed somewhere else in our solar system.
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And at some point, as it was wandering around,
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it got so close to Earth that it ended up captured by its gravity.
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And fans of the third theory believed the moon and the Earth formed at the same time
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from the same proto-planetary disk.
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Before the moon formed, the Earth was a much different place.
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If you could have just one day on Earth without the moon,
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you'd be first surprised by the days and nights.
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They wouldn't be as stable as they are today
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because the moon helps to keep the Earth's axis stable.
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Days were shorter back then.
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The Earth had been rotating much faster before the moon formed.
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Its gravitational pulse slowed the rotation of our planet,
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which means days got longer.
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The Earth's rotation is getting slower through time,
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but at a really small rate.
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Some predictions say that in a billion years,
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a typical day will be between 25.5 and 31.7 hours long.
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If 24 hours is not enough time for you,
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it'd just wait a billion years.
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But yeah, if you're the type of person that likes to take things slow,
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you'd definitely have to hurry back then.
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Although there weren't many things you could do back then,
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then to fill your time,
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besides, you know, sailing across the hot lava, collecting rocks,
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or hoping not to get hit in the head by some fierce meteorite falling onto our planet.
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But if you were patient enough,
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maybe you'd see something really cool.
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Water coming onto our planet for the first time.
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There was a rain of fiery meteors coming from the sky
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and they kept slamming into our young Earth.
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It looked devastating at first,
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but some of this falling debris probably held water.
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Many believed the asteroids and comets that bumped into our home planet
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carried tiny amounts of water.
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But considering this meteorite shower lasted more than 20 million years,
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maybe even up to 200 million years,
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it's not that unusual that after a while,
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puddles of water started to collect across the surface.
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And as the water evaporated within the atmosphere,
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it would fall back down, forming lakes, rivers, seas,
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and eventually oceans.
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Only at that point, there was a chance for some primitive life to evolve
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sometime in the future.
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Earth started its transition from a hot ball of magma to the world we know today.
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Before that, it would be too hard for life to exist there.
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Even if it had happened somehow,
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all those meteor and asteroid collisions would have probably destroyed it.
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Also, you wouldn't be able to survive without an oxygen tank.
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The Earth did have an atmosphere,
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but it wasn't like the one we have today.
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Scientists believe it was composed of water vapor, methane, ammonia,
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and some other gases released from volcanic activity.
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Basically, it was too toxic since there were volcanic eruptions all the time.
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And the temperatures were way higher,
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so just standing at these early stages of Earth
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wouldn't be such a pleasant experience.
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Also, there could even be some form of life at that time.
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In its early stages, when everything was so chaotic,
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it wasn't covered in oceans, trees,
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or stunning landscapes like today, but in molten magma.
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I mean, the earliest form of life we know about
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are fossils of microorganisms found in hydrothermal vents,
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and they're thought to be 1.4 billion years old.
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And scientists assume the earliest time for life to show on Earth
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could be 4.2 billion years ago, give or take.
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So, with the right equipment, you could even see some single-celled organisms
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like bacteria somewhere across our chaotic planet,
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even before the Moon was there.
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The Moon's gravitational pull on the Earth creates tides in the ocean,
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which means it probably helped mix and circulate ocean water,
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maybe even shape them.
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The tides without the Moon would be much smaller,
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because the gravitational pull is what causes the tides
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The Moon also affects life in the ocean.
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Over time, animals in the ocean have changed and adapted
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to the changing water levels caused by the Moon's gravity.
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Even just the Moon light has a big effect on sea creatures.
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For example, corals use the Moon's cycle to release their eggs
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at the same time and with stronger tides to help carry the eggs.
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Baby sea turtles use the Moon's light shining on the water
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to guide them from their nest to the ocean.
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Who knows which directions life on the Earth would have taken if,
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at some point, billions of years ago,
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we didn't get our lunar buddy to follow us along the way.