Origin, composition and internal structure of the earth

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process of the formation of the solar system
Solar system formed about 4.6 billion year ago, when gravity pulled together low-density cloud of interstellar gas and dust (called a nebula)(movie). The Orion Nebula, an interstellarcloud in which star systems and possibly planets are forming.

 Solar System Formation. Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust.
Earth Differentiation. 


After the initial formation of protoplanets, remaining gas and dust was gradually blown away by the solar wind during the heat-up phase of the young sun. At that time our earthwas probably a barren planet, pockmarked by meteorite bombardment, and may have looked on the surface like the Moon.
 composition and characteristics of the core, mantle and crust
The solid, inner core of iron has a radius of about 760 miles (about 1,220 km), according to NASA. It is surrounded by a liquid, outer core composed of a nickel-iron alloy. ... Earth has multiple layers: the crust, mantle and core

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posted by: Riztie Rabacal

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