The exosphere is the outermost layer of Earth's atmosphere. It's so thin that it's practically a vacuum. Two things you can find in the exosphere are:

1. Very low density atmospheric gases: The exosphere contains trace amounts of gases like hydrogen and helium. These are the lightest elements, and they are able to escape Earth's gravity and drift into space.

2. Space debris: The exosphere also contains a significant amount of space debris, including satellites, rocket parts, and natural meteoroids. This debris is constantly bombarded by solar radiation and micrometeoroids, causing it to degrade and eventually break apart.