Don’t let the name fool you. Our solar system’s small bodies—asteroids, comets and meteors—pack big surprises. Asteroids and comets—and the meteors that sometimes come from them—are leftovers from the formation of our solar system 4.6 billion years ago. While the planets and moons have changed over the millennia, many of these small chunks of ice, rock and metal have not. They are a lot like a fossil record of planetary evolution.
There are currently known asteroids and known comets.