Co-orbital

A co-orbital orbit, also known as a co-orbital configuration, a co-orbit, or a 1:1 or 1:−1 mean-motion resonance, is when two or more objects occupy the same orbit and does weird physics things such as bouncing off each other at a certain point in their orbit or spraying out dust when in contact with the other object due to gravity.

An asteroid, 3753 Cruithne, is in a co-orbit with Earth. 2 saturnian moons, Janus and Epimetheus are in co-orbit of each other.