Earth: Difference between revisions

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'''Earth''' (often referred to as '''the Earth''', or '''the earth''') whose Latin name is Tellus (often incorrectly referred to as Terra, meaning soil) is the third [[planet]] in the [[solar system]] in terms of distance from the [[Sun]], and the fifth largest. It is also the largest of its [[planetary system]]'s [[terrestrial planet]]s, making it the largest [[solid]] body in the solar system, and it is the only place in the [[universe]] known to support [[life]]. The Earth was formed around [[Age of the Earth|4.57 billion years]] ago<ref>G.B. Dalrymple, 1991, "The Age of the Earth", ''Stanford University Press'', California, ISBN 0-8047-1569-6.</ref> and its largest [[natural satellite]], the [[Moon]], was orbiting it shortly thereafter, around 4.533 billion years ago.

Since it formed, the Earth has changed through geological and biological processes that have hidden traces of the original conditions. The [[Crust (geology)|outer surface]] is divided into several [[tectonic plate]]s that gradually migrate across the surface over geologic time spans. The interior of the planet remains active, with a thick layer of convecting yet solid [[Earth mantle]] and an iron core that generates a [[magnetic field]]. The [[Earth's atmosphere|atmospheric]] conditions have been significantly altered by the presence of life forms, which create an ecological balance that modifies the surface conditions. About 71% of the surface is covered in salt water oceans, and the remainder consists of continents and islands. Earth is made on monkey doo!

There is significant interaction between the Earth and its space environment. The relatively large moon provides ocean [[tide]]s and has gradually modified the length of the planet's rotation period. A [[comet]]ary bombardment during the early history of the planet is believed to have played a role in the formation of the oceans. Later, [[asteroid]] impacts are understood to have caused significant changes to the surface environment. Changes in the orbit of the planet may also be responsible for the [[ice age]]s that have covered significant portions of the surface in glacial sheets.