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Name: emily
Status: student
Age: 9
Location: N/A
Country: N/A
Date: 1999 - 2000


Question:
Why does the moon rotate around the earth? Why doesn't the earth rotate around the moon? Wouldn't it get the same results?


Replies:
Both the earth and the moon rotate around the center of mass of the earth-moon system. This is located inside the earth, because the earth is so much more massive than the moon.

Barrans


Emily,

In your science class you probably learned that the earth revolves around the sun. That is because the sun is much larger and we are held in place through attraction to the sun. In the same way, the moon is much smaller than the earth. The moon is held in place due to the gravitational pull of the earth. Another way to say this is that the moon is not mass ive enough to make the earth rotate around it, the opposite is true.

Your question is similar to asking why a dogs tail does not wag the dog. You know, of course, that the dog wags the tail. :)

Thanks for using NEWTON!!

Ric Rupnik


The Earth and the moon orbit each other. More precisely, they both orbit the center of mass of the earth-moon system. Since the earth is much more massive than the moon, the center of mass is much nearer the earth.

Tim Mooney


The moon seems to rotate about us, because we are the ones doing the looking. if you were standing on the moon, yes it would seem like the earth is rotating about the moon. But if you were standing somewhere else, say on the sun, it would seem like both the earth AND the moon are rotating around the sun, and also more or less around each other, like two people doing a dance, holding on to each other, while they both danced around the entire dance floor.

S. Ross



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