Five serious theories have been proposed for the formation of the Moon (not counting the one involving green cheese):
1. The Fission Theory: The Moon was once part of the Earth and somehow separated from the Earth early in the history of the Solar System. The present Pacific Ocean basin is the most popular site for the part of the Earth from which the Moon came.
2. The Capture Theory: The Moon was formed somewhere else, and was later captured by the gravitational field of the Earth.
3. The Condensation Theory: The Moon and the Earth condensed together from the original nebula that formed the Solar System.
4. The Colliding Planetesimals Theory: The interaction of earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the Solar System led to their breakup. The Moon condensed from this debris.
5. The Ejected Ring Theory: A planetesimal the size of Mars struck the earth, ejecting large volumes of matter. A disk of orbiting material was formed, and this matter eventually condensed to form the Moon in orbit around the Earth.
2006-09-19 15:44:22
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answer #1
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answered by Otis F 7
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Personally, I think a comet ventured to close to the gravitational pull of the earth and became trapped in its orbit, or possibly a satellite of Mars.
Before the modern age of space exploration, scientists had three major models for the origin of the Moon. The fission from Earth model proposed that the young, molten Earth rotated so fast that it flung off some material that became the Moon. The formation in Earth orbit model claimed that the Moon formed independently, but close enough to Earth to orbit the planet. The formation far from Earth model proposed that the Moon formed independently in orbit around the Sun but was subsequently captured by Earth’s gravity when it passed close to the planet. None of these three models, however, is entirely consistent with current knowledge of the Moon. In 1975, having studied moon rocks and close-up pictures of the Moon, scientists proposed what has come to be regarded as the most probable of the theories of formation: a giant, planetary impact.
The giant impact model proposes that early in Earth’s history, well over 4 billion years ago, Earth was struck by a large planet-sized body. Early estimates for the size of this object were comparable to the size of Mars, but a computer simulation by American scientists in 1997 suggested that the body would have to have been at least 2.5 to 3 times the size of Mars. The catastrophic impact blasted portions of Earth and the impacting body into Earth orbit, where debris from the impact eventually coalesced to form the Moon. After years of research on lunar rocks during the 1970s and 1980s, this model became the most widely accepted one for the Moon’s origin. The giant impact model seems to account for all of the available evidence: the similarity in composition between Earth and Moon indicated by analysis of lunar samples, the near-complete global melting of the Moon (and possibly Earth) in the distant past , and the simple fact that the other models are all inadequate to one degree or another. Research continues on the ramifications of such a violent lunar origin to the early history of Earth and the other planets.
Microsoft ® Encarta ® 2006. © 1993-2005 Microsoft Corporation. All rights reserved.
2006-09-19 14:57:06
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answer #2
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answered by cotterall&elaineadams 2
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The currently accepted theory is that early in the Earth's history,that an object about the size of Mars collided into Earth,and the debris flung into space from the impact formed into the moon.
2006-09-19 16:29:19
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answer #3
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answered by That one guy 6
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I believe the going theory is that before the Earth fully formed, another object (proto-planet) about the size of Mars side-swiped the proto-Earth, send a large amount of material into orbit, which eventually aggregated and condensed into the Moon.
2006-09-19 14:30:08
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answer #4
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answered by JBarleycorn 3
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Hi. I think the moon was once a part of Earth and something, maybe a collision, scraped off some of the crust and this material formed the moon.
2006-09-19 14:19:30
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answer #5
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answered by Cirric 7
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I think the moon was created by an impact with the earth of another large body.
2006-09-19 16:36:06
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answer #6
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answered by bprice215 5
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its want not wont
people not peaple
different not difrent
theories not theries
do not to
2006-09-19 14:23:12
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answer #7
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answered by Adam 4
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A big planet that hit against the Earth that stripped it bare and became our moon.
2006-09-20 01:32:14
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answer #8
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answered by Eddy G 2
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Came from the pacific ocean when something slammed into the Earth.
2006-09-19 15:49:02
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answer #9
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answered by dirtmerchant_12b 3
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a bit off another planet ?
supposingly according to astronauts that were on the moon, the moon seemed hollow....
and also, without the moon, we could be in trouble, like, is the moon created for us, like to evolve..wow man, blows your mind.
(well, a bit)
2006-09-19 14:20:53
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answer #10
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answered by realdragonflame 3
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