size/impact difference.

To add onto Size/Difference, also time. When the moon was created; life wasn't what it was say during the time of dinosaurs. Also imagine that we say dinosaurs, but thats a massive amount of time. There were numerous periods of near total extinction events, where populations and species bottlenecked. A meteor was only one of these events over our 4+billion life span as a planet.

First one was before the Solar system finished forming, no life, it was also the size of Mars. The Moon is a combination of matter from that object and matter thrown up from Earth. Second one was tiny by comparison and we actually are pretty sure we found the crater

Because there was no life around yet the first time, and because the second time is was an actual asteroid instead of a planet.