moons craters...

[ving (David)]

Ok guys riddle me this... this atricle from space.com
http://space.com/scienceastronomy/05...ter_count.html
states that most moon/planet craters are in fact made not from primary impact but from secondary. I dont mean bouncing asteriods but debris broke from the said primary impact.... head hurting....

ok so a lump of rock slams into a moon surface then breaks up. Now I am not a physics expert but i would have said that the debris would have reached exit velocity for these low gravity places and would be floating off in another direction, not landing again with enough force to create anothersmaller impact crater... infact if they did land again it would be more of a skid mark than a crateer (depending on trajectory i guess)....


er... what do you guys think?

[davidpretorius]

green cheese does not shatter, it absorbs! so this crater myth is busted!!!

[rumples riot]

Even though gravity is low, the exit velocity of the Moon is still significant. So secondary craters will also form. Like you the physics is beyond me, its been a long time.

[Hitchhiker]

Some debris from impacts does reach escape velocity. Meteorites that originated on the Moon and Mars have been found on Earth!

I guess the majority of the debris does come back down onto the body and cause secondary impacts while some can escape altogether.

[ving (David)]

see now i'd have thought that considering the impact velocity of the majority of these objects they would for the most part be able to ecsape the flimsy atmosphere of the moon...

and as for the non escaping debris, i wouldnt ahve thought it would hit with enmough force to create a crater! if it did, i'd expect the crater would be of similar size to the object making it and the said object to more or less be sitting in the middle of it