What would happen to earth if a massive asteroid hit the moon?

Question

What would happen to earth if a massive asteroid hit the moon hard enough to push it out of its present orbit?

Answer 1

It would a catastrophic event for earth, probably fatal for all species, save the cockroaches.

There's a delicate equilibrium in the orbit of the Earth-Moon system around the Sun.  Loosing the Moon will make the system lighter bringing us a little bit away from the Sun.  That itself is deadly.

Answer 2

Well the fact that it hasn't happened yet kind of makes me think that there isn't a big enough asteroid that could do that except maybe Ceres but Ceres is a dwarf planet now, so i would have to say that even a massive asteroid wouldn't knock the earth out of it's orbit. An asteroid the size your talking about though would end all life on earth, even those people in deep level bunkers would be killed.

Answer 3

That asteroid would have to be very big!  

Answer 4

That would depend on the size of the asteroid and how fast it's moving.  As you can see with a good pair of binoculars, the moon is completely covered with impact craters, and NASA pictures from the far side show thousands, if not millions of impact craters.  The moon can take a pretty good size knock and not even flinch, so to speak.

Any size asteroid impact will affect the moon's orbit, but most known asteroids would only push it millimeters... if that much.  I imagine there are massive near-earth objects that could substantially affect the moon's orbit though.

Answer 5

Theoretically, every asteroid, however small, does push the moon out of its present orbit. It may be pushed by a micron, that is still being pushed.

Anything that hits the moon affects it, and the moon then has to settle out on a new, slightly different orbit. Now, do you mean that something would slam in it hard enough that it is then free of Earth's gravitation?

Anything that would be massive (i.e. about as large as the moon itself) and fast enough to do so would shatter the moon, and thousands of city-sized chunks of rocks would be sent in all directions, some of those falling on Earth. Then, we would go the way of the dinosaurs.

Answer 6

No such massive asteroids exist in the solar system. The Moon has been impacted countless times by large asteroids, which caused to scars we see on the Moon's face, but none has been large enough to knock the Moon out of its orbit.