Summary:
- Astronomers have discovered that the Earth has a "mini-moon" or "quasi-satellite" that has been orbiting our planet for about a century.
- This small object, named 2016 HO3, is about 40-100 feet in diameter and has been circling the Earth since at least 1913, making it the longest-known natural satellite of our planet.
- The object is considered a "quasi-satellite" because it doesn't orbit the Earth in a traditional way, but rather a more complex path that keeps it as a constant companion to our planet.