system
Given the following post, respond as if you're commenting on Reddit:
human
Martian meteorites are found on Earth, is the converse also true?

Are there pieces of the Earth on Mars?  Have any been found?  If so, what can they teach us about Earth's past?

EDIT: some of these responses are very thought–provoking, thank–you!
gpt
Almost certainly. However, whereas the Earth has several billion humans swarming all over it Mars has only had a handful of landers and rovers exploring a tiny area of the surface. It'll probably be quite some time before an Earth meteorite is found on Mars.

The biggest thing such meteorites would likely tell us is the composition of the ancient atmosphere of Earth.