system
Given the following post, respond as if you're commenting on Reddit:
human
If the moon was indeed created by the collision of the earth and another protoplanet, how is it that we don't see any traces of it down here ?
gpt
We do, it's just that down here we just call it ground. One of the biggest pieces of evidence pointing to the impact formation theory is the similar composition between the moon and the earths crust. Since we live on Earth, we have a bias towards it, so we say that we find traces of Earth up there, not vice versa.