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What would happen to the moon if the earth is gone? Will the moon find another planet to circle around? If yes, which would be that planet? Would the moon go on in the same circle without a planet? Will the moon be gone before us or will be death with us? What will happen?
Question Date: 2015-01-21
Answer 1:

Well the moon like the earth revolves around the Sun. If you were far away you would see that as the moon goes around the sun it wobbles a little bit because it also revolves around the Earth.

If the earth suddenly disappeared...POOF!!!!!, the moon would continue in its orbit around the Sun although the wobble in the orbit would disappear.

The moon and the earth are actually exchanged energy via the tides. Yes go to the beach at different times and you will notice high tides and low tides. These tides are caused in part by the moon.

The friction of the oceans against the shoreline is dissipating energy, so the earth's spin rate (the length of the day) is decreasing... 3 billion years ago there were 16 hours in the day!!! Not 24.

A corollary of this decreasing spin rate is that the moon is receding from earth by about 1 to 2 inches per year!!!! In several billions of years the moon will circle the earth once every 47 days and the moon will be much farther away! But that is not for many billions of years. Long before that happens however the Sun will run out of fuel and swell up to be a RED GIANT star. When that happens earth and moon will be destroyed. But that will not happen for another 5 billion years !!!

Answer 2:

Good question! The moon orbits (travels around) the earth because of the inertia of the moon and the gravitational force between the earth and the moon. So what does that mean? The inertia of an object means that it will tend to continue to move in the same direction at the same speed unless a force “pushes” or “pulls” it. The gravitational force between the earth and the moon “pulls” the moon toward the earth, and this pull is balanced by inertia, so the moon doesn’t fall into the earth. The moon’s inertia would cause it to go flying off into space in a straight line if there weren’t anything pulling on it. If the earth were to disappear, there would be no strong gravitational “pull” on the moon, and it would go flying off into space in a straight line. The moon would not continue in its circular orbit without a planet or other object “pulling”. I included a picture that shows what would happen. moon around earth

Imagine that you have a tennis ball tied to a string and you are swinging it around above your head. In this example, your hand is the earth and the tennis ball is the moon that is orbiting around your hand. The ball is attached to your hand by the string so it can’t fly off. The tension in the string is like gravity. You can feel the tennis ball tugging on the string– that is because it has inertia and wants to travel in a straight line. If you cut the string (making the “gravity” disappear) the ball would go flying off.

All massive objects in our solar system and the universe have gravitational forces between them. That means that even if earth disappeared, the moon would still be “pulled” by other things. The moon would eventually (maybe after a very long time) get “caught” by the gravity of another object and start to orbit it (circle around it). That object may be another planet, but it is very difficult to predict which planet it would be. I suppose that would depend on what direction the moon was traveling when the earth disappeared and it went flying off. Remember that the objects in our solar system also orbit around the sun. The moon is orbiting earth, but both are orbiting the sun.

The moon has been around for 4.5 billion years. The moon will still be around long after we are gone.

Answer 3:

Ha! That is an interesting thought. What would happen if the Earth was gone and the moon was still there? Well, let’s start with gravity. Gravity is the force that makes objects fall toward the ground. It is the force that keeps your feet on the ground and makes you come back to the ground when you jump. If there was no gravity, you would fly away from the Earth. An object has a large gravity force when it is big and when it is close. So Earth is very big so it has a very big gravity force. The sun is bigger than the earth but it is very far away so the force from the sun is much smaller than from the Earth. This is good news. Otherwise you would fly toward the sun.

The moon is attracted by the Earth just as you are and therefore rotates around it. If the Earth was suddenly not there anymore, the next strongest gravity force will come from the sun. There are other planets that are closer (for example Venus and Mars) and the moon could circle around them but the sun is so big that it has the strongest gravitational force. The shape of the “circle” around the sun (we call it “orbit”) would be a little bit different if the Earth was not there.

The moon and the Earth will be there as long as the sun still exists but in a very very very long time (over 1000 times 1000 times 1000 years), the sun will stop to be and with it, the Earth and the moon will go as well.

Answer 4:

What an interesting question! I guess it depends on how the earth disappears.

If you're talking about something like using an eraser to delete earth then my guess is that the moon would not be significantly affected and will just continue going around the Sun (which it already does anyway). If you're talking about something dramatic like an explosion that torn Earth to pieces then I would say that it might have an effect on the moon's orbit. I could imagine it flying off away from where the explosion happened and either fly towards the Sun or towards the outer solar system, where it could get attracted by other planets (maybe Mars?).

Before I end I just want to tell you that I'm not entirely sure about what would happen. What I told you is what I think, and it might be a good idea to ask other people for their opinion. I still hope I gave you a good answer though. Good luck with your studies!


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