To what extent does the moon shelter the earth from asteroid impacts?

Question

Is there any measurement of the ration of impacts the moon takes vs. impacts the earth takes?

sorry , that should read 'raio' not 'ration'

Many good answers so I would like to put this to a vot. Thanks to all.

Answer 1

Considering how far away the moon is and the space it takes up, far less than 1%. But, we see far more craters on the moon because, there's no atmosphere for meterorites to burn up before hitting, there's no erosion as on Earth, and there's no oceans to prevent us from seeing craters on the surface.

Answer 2

Well, an asteroid could hit either the moon or the earth directly. Many thousands have already done so. Both the earth and the moon are subject to massive asteroid impacts which would quickly destroy them. But if the moon were hit and destroyed the earth would be in a lot of trouble even if none of the fragments hit the earth. This is because the moon stabalizes the earth's tilt, restricting it to polar angles of 10 to 20 degrees. Without the moon the earth's axis would begin tilting more and more until it was swinging as much as 90 degrees back and forth. This would make the equator rotate around what are now the N. and S. poles. In such conditions there would be no seasons as we now know them, and most forms of life on earth would go extinct rather quickly, including our own.

Answer 3

The Earth is a target13 times larger in area than the moon. So, it will have taken 13 times as many hits. In fact, due to its much greater gravity, that figure would most likely be higher.

From the distance of earth, the moon is a very small target, as can be judged by anyone who can stick a thumb out and cover it up. So, it will intercept a very small proportion of the incoming shrapnel.

In addition to other reasons given above for Earth not showing the cratering like the moon, is that tectonic forces on Earth have turned over the crust many times over the last 4 billion years.

Most of the craters on the moon are scars from bombardment in the early history of the Solar System. The Earth's fluidity would have buried its own scars in the few hundred million years after that period.

That is not to say that new craters are not possible. The moon took measurable hits in 1975, as measured by seismometers placed on the moon by the Apollo astronauts.

Answer 4

I don't think the Moon shelters to Earth at all. Some asteroids might be deflected away from Earth by the Moon's gravity, but other asteroids that would have missed Earth get deflected into the Earth by the Moon's gravity. So I see no net sheltering effect at all.

Crater counts on Earth are unreliable because they get erased by weathering and geological processes too quickly, so I don't think anyone has any idea what the ratio of impacts is.

Answer 5

It would certainly appear that the moon gets hit far more often than the Earth, but that's not really true. The Earth would have a surface similarly scarred by impacts if it wasn't for it's active geology, atmosphere, and oceans. Over the Earth's 4.5 billion year lifetime-to-date, active geology means it recreates its surface constantly with lavaflows and moving geologic plates. It's atmosphere prevents smaller rocks from ever actually reaching the surface, as well as helping to shape the surface itself with winds. The moon on the other hand has been geologically inactive for a very long time. You can still see evidence of it's active geology in the darker patches you see, called maria, or seas. These are areas where lava flows have erupted and filled in basins left by impacts. However, the moon has not received any significant impacts for a very long time, just as the Earth has not. It still gets hit by small rocks just as the Earth does. Our atmosphere burns most of them up, and those it doesn't are too small to do any real damage, but the Moon doesn't have that luxury.

The moon is too small of a target and too gravitationally insignificant for it to be of any protection to the Earth. If an asteroid or other large celestial object was heading for Earth, and the Moon managed to intercept it, it would be pure blind luck. The moon has done a lot of great things for our planet, but it's unlikely it will be our savior against an extinction-level impact.

Answer 6

The Earth is protected by the moon from asteroids only when the moon is positioned to cover the Earth, like in a solar eclipse. The moon's gravitational pull will help the asteroids to hit the moon or fling it out into space with a 'slingshot' effect with the Earth's gravity as well. It likely the asteroid will be pulled to the sun and it is gone.

Answer 7

The moon protects the earth from asteroid impacts about as well as a postage stamp would protect you from the rain.

The moon is too small, is too far away, and moves too much to protect the earth from asteroids.

What keeps the earth from feeling the effect of asteroids is the atmosphere. Most asteroids burn up in the atmosphere before colliding with the earth. Those that do actually collide are too small (with very few exceptions) to have an effect.

Below is a link to information regarding a recent event that had the force of a small nuclear weapon. However, it still failed to impact. It disentegrated, and since it's explosion occured over the sea (Mediterranean) there was no crater.

http://en.wikipedia.org/wiki/Eastern_Mediterranean_Event

Answer 8

Only if the moon gets between the earth and the asteroid at the right time.The asteroid has a path around the sun just like everything else in our system.Anything beyond is still traveling in one direction.The moon just happened to be there and the reason you see so many craters on the moon is because there's no atmosphere to burn them up.The earth would look like the moon too if there were no atmosphere.

Answer 9

If the moon shelters us from any asteroids, it can easily redirect an asteroid so it will hit us. So there are no benefits what so ever.

Answer 10

I think it would be bad if a meteor hit the moon because all that ruble would go to the earth and cause catastrophic damage