My daughter just asked what happens.?

Question

If an asteroid hits the moon instead of earth

Answer 1

The moon has been struck literally thousands of time in the past by asteroids of all sizes... that is why there are craters on the Moon (the lack of wind, rain etc means that they don't get eroded which is why we can see so many dating back millions of years).

Small sized chunks of rock hit the Moon quite regularly and obviously have no effect on Earth at all. The problem MAY arise if a larger asteroid struck the Moon but there are a number of possible effects, depending on:
* how the impact occurred (direct hit, glancing blow)
* how big and how fast the asteroid was
* the location of the impact (on the side facing Earth or on the far side, for example)

There could be all sorts of possibilities:-
* no effect felt on Earth
* Earth is showered by small fragments from the impact
* large chunks or the Moon and/or the asteroid break off and hit the Earth (or start orbiting the Moon and/or Earth or maybe just fly off into space)
* a very large chunk of the Moon breaks off and forms a small "second Moon" which orbits either the Earth or the Moon
* the Moon is smashed into fragments so that we end up with a ring of debris orbiting the Earth, a bit like Saturn's rings.

Without knowing the exact nature of the asteroid and it's projected impact there is just no way of even beginning to guess the consequences of a large asteroid impact on the Earth.

The good news is that such events are extremely rare and the chances of one happening in your daughter's lifetime are very very small indeed!

Answer 2

If an asteroid the mass of the on the one that possibly caused the extinction of the dinosaurs struck the moon would the material expelled from the crater possibly reach earth and would it create massive meteorite impacts.

The asteroid which may have wiped out the dinosaurs was probably somewhere between 2 and 10km in size. An asteroid that large striking the Moon would release a large amount of energy and it probably would eject some of the moon rock into space, however I would guess that the bits would be quite small, so if they happened to be going in the right direction to hit the Earth they wouldn't cause too much damage. Around 15 meteorites found on Earth have been identified as originating on the Moon, so it obviously is possible for ejecta from the Moon to reach the Earth, however this is a tiny amount relative to the total number of meteorites found on the Earth

Answer 3

I take it she means meteor / meteorite ("meteors" are what they're called while descending, "meteorites" when they've hit the ground already)

Next time you see the moon, take a look at it through binoculars or a telescope.

See all those marks on it?
Thats what happens.

The moon doesn't have an atmosphere to cause friction with incoming stellar bodies, hence they will hit the surface at terminal velocity... throw up a lot of debris (dust and small rocks, etc) and leave a crater.
The same thing would typically happen on Earth but for the fact that this planet has quite a dense atmosphere, so any meteors hurtling down through the atmosphere are too small to make it through without entirely burning up due to the friction.

In any case, it would take a VERY large meteor hitting the moon for it to throw up enough debris with enough force for it to cause any detriment to the Earth.... and at the sizes involved, it would probably hurtle toward the Earth rather than the moon anyway because this planet is bigger than its orbiting satellite and has stronger gravity.


Oh... and for the record, most of the really big craters on the moon (and in fact the middle-sized ones too) are billions of years old.... from the time when the two bodies (moon and Earth) were still forming and there were all kinds of meteors hurtling about. There are far less these days.

Answer 4

I don't know if asteroids are big enough to affect the moon as I'm not experienced on the matter, but I think that if the asteroid was big enough to do significant damage to the moon then it would alter the tides and other magnetic fields of the earth and things. So we would get more tsunamis and other water related problems, and probably more. That would only be if anything drastic happened to the moon though.

Answer 5

It would leave a crater on the moon instead of Earth, if you look at pictures of the moon you could see that there are many craters on the moon.

Answer 6

if that happened and lets say the moon went off coursse then the tides would go wonky but loads of asteroids have hit the moon thats what creates the craters

Answer 7

depends on the size of the asteroid and angle of impact - it has already happened. Moons of planets are very often pieces of the larger planets that have sheared off from impact or explosion anyway

Answer 8

That depends on the size of the asteroid.

Answer 9

Then it makes a crater in the moon's surface.

Answer 10

Tell her not to worry it has been hit by them plenty of times. She is probably too young to have to worry about big ones. Dont fill her mind with fear yet.