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How did the Earth Get to Look Like This?
Two significant questions to now ask:
1. Where did the water on the earth come from?
2. This nearby object has a density of 3.3 grams per cubic centimeter. Is this a problem?
The Origin of the Moon:
Until recently, this was not understood. The moon has long been an anamoly because its mass compared to the earth is 1/80 and there is very large for a planetary satellite
Possibilities for Lunar Origin:
The above 3 scenarios for lunar formation are all physically implausible so why is the moon there?
Let's imaging the following sequence:
Outgassing --> Early Formation of the Earth's Atmosphere
Present day composition of volcanoe effluents:
It is likely that there was NOT enough water released via outgassing to account for the present day oceans
Most of the water was likely delivered to the earth after it formed via collisions with left over planetisimals and cometisimals. The influence of Jupiter on the orbits of leftover cometisimals may well be key.
Tidal forces from a newly formed moon may also be key in promoting first stages of development of life as well.
Hence the earth may need both Jupiter and the Moon if it is to ask a question sometime later.
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