If the force of gravity between the earth and moon were reduced how might the Moon's orbit change?

Answer 1

The force of gravity varies with the inverse square of the distance. That means if the distance were doubled, the force would decrease to one-quarter.

So if the Moon were to move to 90% of its current distance, the force of the Moon's gravity on things on Earth would increase by 23%.

The effect of this gravity on things on Earth would be 23% higher than "almost negligible"; the only visible effect would be on the tides.

Answer 2

Earth's gravity causes the moon to orbit the Earth once every 29.5 days.

The Moon is actually moving away from us at about 4cm per year, and it got something to do with lunar tidal bulges or something like that Tides with another word.

As to why the moon is moving away, as has been mentioned, it is due to the lunar tidal bulges.

The Moon causes two bulges to form on the Earth, Ideally. they would form on a line joining them with the moon.

The Earth however rotates faster than the Moon revolves around the Earth. And as has also been mentioned, there is a friction between the rotating Earth and the Tidal bulges. This causes the tidal bulges to tend to rotate along with the Earth. Thus there are two forces acting on the bulges that must balance out. When they do, the result is that the tidal bulges tend to lead the Moon a little.

And this tug of war has two effects, the friction between the bulges and the Earth tends to slow the Earth, and the moon's tendancy to want to line up with the title bulges tends to pull it forward in its orbit.

Now the thing is, that when an object is given a forward thrust it moves into a higher orbit. (basically if given a forward thrust at any given point of an orbit, The radius on the opposite side of the orbit increases. Since the moon gets this thrust along its entire orbit, it follows an outward spiral.)

Left alone, this will continue until The Earth's rotation slows to the point where it matches the period of the Moon's orbit. (Since the Moon's orbital period is also increasing, this will happen when they both are about 2 months long.)

If we only had to concern ourselves with the Moon and Earth, this situation would be stable and wouldn't change.

However, the Moon isn't the only body that causes tides, the sun does too. These tides are about 1/2 the magnitude of the Earth's (so even if we did lose the Moon completely, there would still be tides.)

The Solar tidal bulges create friction with the Earth too, and results in a continuing slowing of the Earth's rotation.

This, in turn, causes the Earth to start to rotate slowerthan the Moon revolves, causing the Lunar tidal bulges to lag behind the Moon and tug it backward, which will pull the Moon into a lower, faster orbit. (And the Lunar tides will start to increase in magnitude)

The Moon will continue to fall inward until it passes the Roche limit and it breaks up.

The kicker is, "if left alone". Chances are that the Earth and Moon will not be left alone long enough for this scenerio to take place. Long before then the Sun will expand into a Red giant and likely engulf both the Earth and Moon.

Answer 3

The combined gravity of earth and the moon keeps the moon in orbit around our globe.

This is not all though, the moon's gravity also affects elements on the earth - for instance tidal water is mostly due to the drag created by the gravity of the moon.

A similar effect from earth's gravity field is not apparent on the moon because the moon only has frozen water.

Answer 4

If it happened in a moment, I think the moon's orbit would become much more eccentric (elliptical) than it is now.

the moon's compostition is made of rocky material such as rocka and a lot of dust

Answer 5

I know that the moon's gravity causes tides to form on earth. ( on the beaches) Sorry if it doesn't help! I am only a sixth grader bored to death on the computer! But I know for sure that that is the answer. Hee Hee!!!

Answer 6

-- It would appear larger in the sky.

-- It would revolve around the Earth in a shorter time.

-- It would go through a complete cycle of phases in a shorter time.

-- Tides on Earth would be higher.

-- Earthquakes could be more frequent.

-- Both solar and lunar eclipses would occur more frequently. Unfortunately,

however, solar eclipses would be less spectacular, because the apparent size

of the moon would be larger than the apparent size of the sun, and much of the

solar corona would be obscured during a solar eclipse.

Answer 7

The Moon's gravitational influence causes the ocean tides and the minute lengthening of the day.

Answer 8

It is the main cause of the tides on Earth.

Answer 9

The moon's gravitational pull exerts a powerful pull on the Earths tides

Answer 10

The gravity of moon is responsible for the tides which are caused in the oceans.