Technology1 min ago
Moon orbit and rotation speed. (For a boffin)
Why does the moon rotate at exactly the correct speed to only ever show one face to earth.
Answers
1 to 14 of 14
Long ago when the Moon spun much faster, the Moon's tidal bulge preceded the Earth-Moon line because the Moon couldn't "snap back" its bulges quickly enough to keep its bulges in line with Earth, says James Hilton, Astronomer, U.S. Naval Observatory. The rotation swept the bulge beyond the Earth-Moon line. This out-of-line bulge caused a torque, slowing...
18:28 Wed 11th Jan 2012
I tried to get a simple answer for you, but the best I can do is here..... Don't get too carried away though! http://www.grantchronicles.com/astro29.htm
Long ago when the Moon spun much faster, the Moon's tidal bulge preceded the Earth-Moon line because the Moon couldn't "snap back" its bulges quickly enough to keep its bulges in line with Earth, says James Hilton, Astronomer, U.S. Naval Observatory. The rotation swept the bulge beyond the Earth-Moon line. This out-of-line bulge caused a torque, slowing the Moon spin, like a wrench tightening a nut. When the Moon's spin slowed enough to match its orbital rate, then the bulge always faced Earth, the bulge was in line with Earth, and the torque disappeared. That's why the Moon rotates at the same rate as it orbits and we always see the same side of the Moon.
The Moon is 'tidally locked ' to the Earth in the same way that Mercury is tidally locked to the Sun
http://en.wikipedia.org/wiki/Tidal_locking
The Earth /Moon system is actually one system and it rotates around the common centre of gravity. s the Earth is so much more massive than Earth the centre of gravity is inside the Earth.
Earth / Moon should really be regarded as a double planet as they are so close in size. Such systems always revolve around the common centre of gravity.
http://en.wikipedia.org/wiki/Tidal_locking
The Earth /Moon system is actually one system and it rotates around the common centre of gravity. s the Earth is so much more massive than Earth the centre of gravity is inside the Earth.
Earth / Moon should really be regarded as a double planet as they are so close in size. Such systems always revolve around the common centre of gravity.
Another link here.
http://www.digipro.com/Trials/moon.html
http://www.digipro.com/Trials/moon.html
EDDIE // Earth / Moon should really be regarded as a double planet as they are so close in size. Such systems always revolve around the common centre of gravity. //
That is incorrect.
All systems orbit around a common centre of gravity. That is why orbits are elliptical when referenced to one of the objects.
A double planetary system is defined by the common COG being outside of the bodies. A moon is when the common COG is inside the larger body.
The COG of the Earth/Moon system is about 1700km below the surface of the Earth. Consequently the Moon is definitely a moon and it is incorrect to refer to the system as a double planet.
That is incorrect.
All systems orbit around a common centre of gravity. That is why orbits are elliptical when referenced to one of the objects.
A double planetary system is defined by the common COG being outside of the bodies. A moon is when the common COG is inside the larger body.
The COG of the Earth/Moon system is about 1700km below the surface of the Earth. Consequently the Moon is definitely a moon and it is incorrect to refer to the system as a double planet.
1 to 14 of 14
Related Questions
Sorry, we can't find any related questions. Try using the search bar at the top of the page to search for some keywords, or choose a topic and submit your own question.