Internal Structure of the Earth. Thanks to the seismically, we know how to be the interior of our planet, the core at its center, consists especially of iron possibly solid, liquid outer core would, and then the mantle would happen a thin crust.
Fascinating structure of a typhoon seen and photographed from space by the crew of the Space Shuttle. In this extraordinary image of an event in Earth's atmosphere as comparable to that of a galaxy, Typhoon Odessa shows his eye despite being scary, fascinating. Image top right: Extraordinary photography Kliuchevskoi Volcano in Russia, obtained from space by the Shuttle.
Wonderful picture from a series taken by astronauts from inside the spacecraft Apollo 10, we poke a beautiful blue earth on the moon surface.
The Earth is also unique in the solar system at present active plate tectonics; possibly Mars and Venus in the past have had similar activity.
Top: Great photo obtained on February 24, 2009 Nikon D2Xs digital camera lens of 180 mm, provided by the ISS team in the area of Chile where the Chariton volcano, the eruption can be seen from it.
What figure is our planet?
In ancient times it was believed for example that the Earth was shaped like a flattened disc, like a bowl surrounded by water, and imagined Homer (Greek poet s.VIII BC). Thales of Miletus (630 BC to 545 BC), mathematician, astronomer and philosopher, also envisioned as a flat disk resting on water. It is Aristotle who defines it as a spherical shape due to the observation that makes lunar eclipses, observed that the shadow is cast on the moon, is circular.
In the late nineteenth century they doubted that the Earth had a perfectly spherical, entering on the consideration that it was but irregular spheroid shape.
Today, thanks to the acquired technology during the twentieth century, we know that its shape is flattened at the poles, Ecuador thickens few kilometers, the North Pole is dilated a few meters and the South Pole is also buried a few meters. To know the exact shape of the Earth has developed a science: Geophysics.
Average distance from Sun: 149,600,000 km = 1UA
Mass (Earth = 1): 1.00 ( t)
Mean density (water = 1): 5.52
Radius: 6,378 km
Diameter in Ecuador: 12,756 kilometers
Rotation (with respect to the stars): 23 hours 56 minutes
Orbit: 365.24 days
Orbital speed: 29.79 km / s
Natural satellites: One, the Moon
Bark: Approx. 40 km composed of silicate rocks
Mantle: 2,800 km composed mostly solid silicate rock
Outer core: 2,300 km is estimated composition of molten iron and nickel
Inner core (radius): 1,200 km composition is believed to be solid iron and nickel
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