You might be surprised to learn that there are seven at least orbiting the planet. The big moon that we all see, known as Luna by astronomers, is the only one to observe a strict orbit , and the only one visible to the naked eye but there are six more Near Earth Asteroids which do follow Earth around the Sun.
The first to be identified was Cruithne. It takes its name from Britain's earliest recorded Celtic tribe. It is three miles wide and has a horseshoe shaped orbit. It was discovered in 1997. Since then five more have been found. There names are more like catalogue references than proper names.
Some astronomers say they are just ordinary asteroids taking about the same time to get around the sun as us and occasionally exerting some gravitational influence. In the future one or all of them might settle down into a regular orbit.
The first to be identified was Cruithne. It takes its name from Britain's earliest recorded Celtic tribe. It is three miles wide and has a horseshoe shaped orbit. It was discovered in 1997. Since then five more have been found. There names are more like catalogue references than proper names.
Some astronomers say they are just ordinary asteroids taking about the same time to get around the sun as us and occasionally exerting some gravitational influence. In the future one or all of them might settle down into a regular orbit.