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Human Artefacts Seen On Moon


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I think you're confusing reality with an episode of Space 1999

 

Surely, due to its stronger gravitaional pull the Earth is drawing the Moon toward it

So why don't all satellites fall to earth due to the earth being so massive?

 

It's to do with the speed that they are travelling in relation to the (inverse square) of the distance between them.

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I think you're confusing reality with an episode of Space 1999

 

Surely, due to its stronger gravitaional pull the Earth is drawing the Moon toward it

So why don't all satellites fall to earth due to the earth being so massive?

 

It's to do with the speed that they are travelling in relation to the (inverse square) of the distance between them.

 

I think you'll find they do (eventually)

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Well exactly. So if they are travelling too slow for their orbit they fall to earth. If they are travelling too fast then they move away. So the earth's gravitational pull isn't a variable in calculating whether the moon is moving towards or away from earth.

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Well exactly. So if they are travelling too slow for their orbit they fall to earth. If they are travelling too fast then they move away. So the earth's gravitational pull isn't a variable in calculating whether the moon is moving towards or away from earth.

 

Oh cause the gravitational pull of earth is a variable to be considered, if you don’t consider it all you end up with is a calculation on how fast the moon/satellite is travelling/accelerating away from us in a straight line.

 

With out the gravitational pull of earth there would be no force puling the objects into orbit they would just fly off in a straight line, as it is the moon acts according to the laws of centripetal force.

 

Also satellite orbits do decay when the object slows down. If an object out of our atmosphere is slowed down, normally when passing through a slow wind, it starts "falling" to earth where the gravitational pull of the planet causes the object to speed up again, this in turn forces the object to maintain orbit as the inertia fights against the pull of the earth, at this point the circular orbit has become an elliptical one with an apogee equal to the original circular orbit and a perigee closer in.

 

Now let's imagine that it experiences another velocity reducing event. This time at perigee of its new orbit. Since the satellite starts out at perigee with less velocity, it won't have enough to climb back to its original Apogee. You will have an orbit that has the same perigee but a lower apogee. (If the event is of just the right magnitude, the satellite will enter a new circular orbit at the altitude of the perigee. If it is even greater, the Perigee will become the apogee of a new orbit with an even lower perigee.)

 

Of cause objects within our own atmosphere are constantly fighting against the friction of the atmosphere and so is in a state of perpetual decay, this is factored in at the time of launch to allow the desired life cycle of the satellite.

 

I think I went off at a tangent there but at least someone might find it interesting.

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I'm talking about one orbitital height, the height that the moon is on. If it's travelling faster than velocity required to keep it in orbit it will move away, if it is travelling slower then it will fall to earth.

 

Yes, to work out the speed you need to factor it in but for this purpose it's a constant.

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Shamelessly cut and pasted....

 

"The reason for the increase is that the Moon raises tides on the Earth. Because the side of the Earth that faces the Moon is closer, it feels a stronger pull of gravity than the center of the Earth. Similarly, the part of the Earth facing away from the Moon feels less gravity than the center of the Earth. This effect stretches the Earth a bit, making it a little bit oblong. We call the parts that stick out "tidal bulges." The actual solid body of the Earth is distorted a few centimeters, but the most noticable effect is the tides raised on the ocean.

 

Now, all mass exerts a gravitational force, and the tidal bulges on the Earth exert a gravitational pull on the Moon. Because the Earth rotates faster (once every 24 hours) than the Moon orbits (once every 27.3 days) the bulge tries to "speed up" the Moon, and pull it ahead in its orbit. The Moon is also pulling back on the tidal bulge of the Earth, slowing the Earth's rotation. Tidal friction, caused by the movement of the tidal bulge around the Earth, takes energy out of the Earth and puts it into the Moon's orbit, making the Moon's orbit bigger (but, a bit pardoxically, the Moon actually moves slower!).

 

The Earth's rotation is slowing down because of this. One hundred years from now, the day will be 2 milliseconds longer than it is now. "

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