Question why does the moon move around the earth

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SUMMARY

The Moon orbits the Earth due to its orbital speed, which allows it to maintain a stable orbit under the influence of gravity. This stability is a result of gravity following an inverse square law; if it followed an inverse cube law, orbits would be unstable. The Moon was formed from debris resulting from a collision between Earth and another celestial body, with some rubble achieving just enough kinetic energy to remain in orbit. Importantly, once in orbit, no additional energy is required for the Moon to maintain its speed.

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shobat
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question why does the moon move around the Earth why it doesn't hit the Earth under the effect of gravity??
 
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because the moon is moving with a velocity that is the orbital speed, so it stays in orbit
 
stable orbits are possible because gravity follows an inverse square law
if gravity followed an inverse cube law then all orbits would be unstable and would eventually spiral outward to infinity or inward to the planet surface.
 
shobat, do a google search on "Newton's orbital cannon".
 
the moon is actually moving with more velocity then the velocity orbital speed, so it is moving around a millimetre away from the Earth every year
 
seto6 said:
because the moon is moving with a velocity that is the orbital speed, so it stays in orbit
but why did the moon have orbital speed in the first place and how does it have the same energy to continue with same speed (this question about satellite and other planets too).
 
shobat said:
but why did the moon have orbital speed in the first place
The prevailing theory is that the Moon was created when a collision occurred between Earth and another body. This sent much of protoEarth flying in a spray of rubble. The fate of the rubble can be classified into three categories:
- rubble that acquired little kinetic energy simply fell back to what remained of the Earth, becoming part of the current Earth.
- rubble that acquired a lot of kinetic energy was lost from the Earth system
- rubble that had juuuuuuust enough kinetic energy ended up neither falling back to Earth, nor escaping completely. This rubble continues to this day to ride the narrow line between falling back to Earth and escaping completely. We call it the Moon.


shobat said:
and how does it have the same energy to continue with same speed (this question about satellite and other planets too).

It requires no energy to stay in orbit.
 

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