GovBD.Net

The Core of The Earth - Documentary HD
Description: Scientists believe that deep down inside the Earth, there’s a huge ball of liquid and solid iron. This is the Earth’s core, and it protects us from the dangerous radiation of space.

When the Earth first formed, 4.6 billion years ago, it was a hot ball of molten rock and metal. And since it was mostly liquid, heavier elements like iron and nickel were able to sink down into the planet and accumulate at the core. The core is believed to have two parts: a solid inner core, with a radius of 1,220 km, and then a liquid outer core that extends to a radius of 3,400 km. The core is thought to be 80% iron, as well as nickel and other dense elements like gold, platinum, and uranium.

The inner core is solid, but the outer core is a hot liquid. Scientists think that movements of metal, like currents in the oceans, create the magnetic field that surrounds the Earth. This magnetic field extends out from the Earth for thousands of kilometers, and redirects the solar wind blowing from the Sun. Without this magnetic field, the solar wind would blow away the lightest parts of our atmosphere, and make our environment more like cold, dead Mars.

Although the Earth’s crust is cool, the inside of the Earth is hot. The mantle is only about 30 km beneath our feet, and it’s hot enough to melt rock. At the core of the Earth, temperatures are thought to rise to 3,000 to 5,000 Kelvin.

Since the core is thousands of kilometers beneath our feet, how can scientists know anything about it? One way is to just calculate. The average density of the Earth is 5.5 grams per cubic cm. The Earth’s surface is made of less dense materials, so the inside must have something much denser than rock. The second part is through seismology. When earthquakes rock the surface of the Earth, the planet rings like a bell, and the shockwaves pass through the center of the Earth. Monitoring stations around the planet detect how the waves bounce, and scientists are able to use this to probe the interior of the Earth.
Tags Advexon TV, top ten, top 5, top video, how to fact, 5 minutes, diy, tricks, documentary, documentary bbc, documentaire, documentary film, documentary space, documentaries, national geographic kids, national geographic space, the core of the earth documentary, the core of the sun, earth core documentary, what is inside the earth, what is inside the pyramid, how hot is the core of the earth, bbc documentary, advexon documentary, Core of the Earth, core of the earth, Download Free The Core of The Earth - Documentary HD 3gp, MP4, HD MP4, Full HD Video, Download The Core of The Earth - Documentary HD Video