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  • The script and voiceover for this video were done by Fraser Cain, Publisher of Universe

  • Today, Make sure you check out his channel after this video.

  • Planet Earth. That shiny blue marble that has fascinated humanity since they first began

  • to walk across its surface. And why shouldn't it fascinate us? In addition to being our

  • home and the place where life as we know it originated, it remains the only planet we

  • know of where life thrives. And over the course of the past few centuries, we have learned

  • much about Earth, which has only deepened our fascination with it.

  • But how much does the average person really know about the planet Earth? You've lived

  • on Planet Earth all of your life, but how much do you really know about the ground underneath

  • your feet? You probably have lots of interesting facts rattling around in your brain, but here

  • are 10 more interesting facts about Earth that you may, or may not know.

  • 1. Plate Tectonics Keep the Planet Comfortable: Earth is the only planet in the Solar System

  • with plate tectonics. Basically, the outer crust of the Earth is broken up into regions

  • known as tectonic plates. These are floating on top of the magma interior of the Earth

  • and can move against one another. When two plates collide, one plate will subduct (go

  • underneath another), and where they pull apart, they will allow fresh crust to form.

  • This process is very important, and for a number of reasons. Not only does it lead to

  • tectonic resurfacing and geological activity (i.e. earthquakes, volcanic eruptions, mountain-building,

  • and oceanic trench formation), it is also intrinsic to the carbon cycle. When microscopic

  • plants in the ocean die, they fall to the bottom of the ocean.

  • Over long periods of time, the remnants of this life, rich in carbon, are carried back

  • into the interior of the Earth and recycled. This pulls carbon out of the atmosphere, which

  • makes sure we don't suffer a runaway greenhouse effect, which is what happened on Venus. Without

  • the action of plate tectonics, there would be no way to recycle this carbon, and the

  • Earth would become an overheated, hellish place.

  • 2. Earth is Almost a Sphere: Many people tend to think that the Earth is

  • a sphere. In fact, between the 6th cenury BCE and the modern era, this remained the

  • scientific consensus. But thanks to modern astronomy and space travel, scientists have

  • since come to understand that the Earth is actually shaped like a flattened sphere (aka.

  • an oblate spheroid). This shape is similar to a sphere, but where

  • the poles are flattened and the equator bulges. In the case of the Earth, this bulge is due

  • to our planet's rotation. This means that the measurement from pole to pole is about

  • 43 km less than the diameter of Earth across the equator. Even though the tallest mountain

  • on Earth is Mount Everest, the feature that's furthest from the center of the Earth is actually

  • Mount Chimborazo in Ecuador.

  • 3. Earth is Mostly Iron, Oxygen and Silicon: If you could separate the Earth out into piles

  • of material, you'd get 32.1 % iron, 30.1% oxygen, 15.1% silicon, and 13.9% magnesium.

  • Of course, most of this iron is actually located at the core of the Earth. If you could actually

  • get down and sample the core, it would be 88% iron. And if you sampled the Earth's

  • crust, you'd find that 47% of it is oxygen. 4. 70% of the Earth's Surface is Covered

  • in Water: When astronauts first went into the space,

  • they looked back at the Earth with human eyes for the first time. Based on their observations,

  • the Earth acquired the nickname theBlue Planet:. And it's no surprise, seeing as

  • how 70% of our planet is covered with oceans. The remaining 30% is the solid crust that

  • is located above sea level, hence why it is called thecontinental crust”.

  • 5. The Earth's Atmosphere Extends to a Distance of 10,000 km:

  • Earth's atmosphere is thickest within the first 50 km from the surface or so, but it

  • actually reaches out to about 10,000 km into space. It is made up of five main layersthe

  • Troposphere, the Stratosphere, the Mesosphere, the Thermosphere, and the Exosphere. As a

  • rule, air pressure and density decrease the higher one goes into the atmosphere and the

  • farther one is from the surface. The bulk of the Earth's atmosphere is down

  • near the Earth itself. In fact, 75% of the Earth's atmosphere is contained within the

  • first 11 km above the planet's surface. However, the outermost layer (the Exosphere)

  • is the largest, extending from the exobaselocated at the top of the thermosphere

  • at an altitude of about 700 km above sea levelto about 10,000 km (6,200 mi). The exosphere

  • merges with the emptiness of outer space, where there is no atmosphere.

  • The exosphere is mainly composed of extremely low densities of hydrogen, helium and several

  • heavier moleculesincluding nitrogen, oxygen and carbon dioxide. The atoms and molecules

  • are so far apart that the exosphere no longer behaves like a gas, and the particles constantly

  • escape into space. These free-moving particles follow ballistic trajectories and may migrate

  • in and out of the magnetosphere or with the solar wind.

  • Want more planet Earth facts? We're halfway through. Here come 5 more!

  • 6. The Earth's Molten Iron Core Creates a Magnetic Field:

  • The Earth is like a great big magnet, with poles at the top and bottom near to the actual

  • geographic poles. The magnetic field it creates extends thousands of kilometers out from the

  • surface of the Earthforming a region called themagnetosphere“. Scientists

  • think that this magnetic field is generated by the molten outer core of the Earth, where

  • heat creates convection motions of conducting materials to generate electric currents.

  • Be grateful for the magnetosphere. Without it, particles from the Sun's solar wind

  • would hit the Earth directly, exposing the surface of the planet to significant amounts

  • of radiation. Instead, the magnetosphere channels the solar wind around the Earth, protecting

  • us from harm. Scientists have also theorized that Mars' thin atmosphere is due to it

  • having a weak magnetosphere compared to Earth's, which allowed solar wind to slowly strip it

  • away. 7. Earth Doesn't Take 24 Hours to Rotate

  • on its Axis: It actually takes 23 hours, 56 minutes and

  • 4 seconds for the Earth to rotate once completely on its axis, which astronomers refer to as

  • a Sidereal Day. Now wait a second, doesn't that mean that a day is 4 minutes shorter

  • than we think it is? You'd think that this time would add up, day by day, and within

  • a few months, day would be night, and night would be day.

  • But remember that the Earth orbits around the Sun. Every day, the Sun moves compared

  • to the background stars by about 1° – about the size of the Moon in the sky. And so, if

  • you add up that little motion from the Sun that we see because the Earth is orbiting

  • around it, as well as the rotation on its axis, you get a total of 24 hours.

  • This is what is known as a Solar Day, whichcontrary to a Sidereal Dayis the

  • amount of time it takes the Sun to return to the same place in the sky.

  • 8. A year on Earth isn't 365 days: It's actually 365.2564 days. It's this

  • extra .2564 days that creates the need for a Leap Year once ever four years.

  • 9. Earth has 1 Moon and 2 Co-Orbital Satellites: As you're probably aware, Earth has 1 moon

  • (aka. The Moon). Plenty is known about this body and we have written many articles about

  • it, so we won't go into much detail there. But did you know there are 2 additional asteroids

  • locked into a co-orbital orbits with Earth? They're called 3753 Cruithne and 2002 AA29,

  • which are part of a larger population of asteroids known as Near-Earth Objects (NEOs).

  • The asteroid known as 3753 Cruithne measures 5 km across, and is sometimes calledEarth's

  • second moon”. It doesn't actually orbit the Earth, but has a synchronized orbit with

  • our home planet. It also has an orbit that makes it look like it's following the Earth

  • in orbit, but it's actually following its own, distinct path around the Sun.

  • Meanwhile, 2002 AA29 is only 60 meters across and makes a horseshoe orbit around the Earth

  • that brings it close to the planet every 95 years. In about 600 years, it will appear

  • to circle Earth in a quasi-satellite orbit. Scientists have suggested that it might make

  • a good target for a space exploration mission. 10. Earth is the Only Planet Known to Have

  • Life: We've discovered past evidence of water

  • and organic molecules on Mars, and the building blocks of life on Saturn's moon Titan. We

  • can see amino acids in nebulae in deep space. And scientists have speculated about the possible

  • existence of life beneath the icy crust of Jupiter's moon Europa and Saturn's moon

  • Titan. But Earth is the only place life has actually been discovered.

  • But if there is life on other planets, scientists are building the observatories, space telescopes

  • and missions that will help find it. Huge new telescopes are under construction that

  • will directly observe the atmospheres of planets orbiting other stars, in search of biosignatures

  • - evidence of life. Radio telescopes scan the skies for signals from extraterrestrials.

  • And new space missions are in the works to search for evidence of life on Mars and the

  • icy moons of the Solar System."

  • But for now, Earth remains the only place we know of where there's life. Now that

  • is an interesting fact!

  • Huge thanks again to Fraser Cain for the script and for being the voiceover of this video,

  • click on the link here or in the description to check out his amazing channel.

The script and voiceover for this video were done by Fraser Cain, Publisher of Universe

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? 10 Fascinating Facts About Earth With FRASER CAIN ?

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    Summer posted on 2021/01/12
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