UNIVERSE
PLANETARY INTERIORS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -Answer(s): Laser ranging measurements of the change in the distance from the Earth to the Moon tell us that the Moon is moving away from the Earth at a rate of about 3.78 cm per year.
Detailed explanation-2: -What is most widely accepted today is the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon.
Detailed explanation-3: -Approximately one billion years ago, the Moon orbited the Earth much closer than it does today. The radius of the orbit was only 24400 km. Today, the radius is 385000 km. The orbital period was only 23400 s.
Detailed explanation-4: -“So if the Moon got really close to the Earth, you’d have massive tides to contend with. There would be a lot of coastal flooding. There would be a lot more gravitational influence on the interior of the Earth, so you might also churn up and heat some mantle, leading to a lot more volcanism and earthquakes.”