Origin+of+the+Earth

=WTBW 11/12/07=

Has the Earth always looked the same, if yes why, if no why?
=Origins of Earth=

Geosphere
=__Origin of the Atmosphere__=

//__Consequences__// - Constant volcanism, surface temperature too high for liquid water or life as we know it, molten surface or thin, unstable __basaltic crust____è__ __Ocean Floor.__
=__Origin of the atmosphere__=

Argon --> 0.3% Chlorine --> 0.1%
= = =**__Origin of the Oceans__**= =How were the Earth’s oceans formed?=

=__How old are the oceans__=

Recently, scientists have begun to investigate another potential source of water: comets.
==This theory has been disputed by other studies that indicate that the composition of water contained in comets is different than water found on Earth, although the discovery of new comet fragments has reopened the debate.==

=WTBW 11/20/07=

What are the dimensions of the Earth?
=__Origin of the Geosphere__=

=**__Structure of the Solid Earth__**=

=__Earth Dimensions__=

361 million km (71%) is ocean
=…For comparison=