Home

The formation of Earth occurred as part of the birth of the solar system: what eventually became the solar system initally existed as a large, rotating cloud of dust and gas. It was composed of hydrogen and helium produced in the Big Bang, as well as heavier elements produced by stars long gone. Then, about 4.6×10⁹ years ago, a nearby star probably became a supernova. The explosion sent a shock wave toward the solar nebula and caused it to contract. As the cloud continued to rotate, gravity and inertia flattened the cloud into a disc, perpendicular to its axis of rotation. Most of the mass concentrated in the middle and began to heat up. Meanwhile, as gravity caused matter to condense around dust particles, the rest of the disc started to break up into rings. Small fragments collided and became larger fragments.

These included one collection approximately 150 million kilometers from the center—Earth. As the Sun condensed and heated, fusion started and the resulting solar wind cleared out most of the material in the disc that had not already condensed into larger bodies.

WikiStratigraphy is a free encyclopedia of the Earth's past. Its aim is to become a valuable database of information on as many aspects of the history of our planet as possible, and to put it into anybody's reach.

Retrieved from "http://stratigraphy.wikia.com/wiki/Main_Page"

Wikia