Each year Cruithne's orbit drifts around the Sun relative to Earth. Image credit: Paul Weitz.
At its closest approach, which happens every 100,000 years, Cruithne comes within about 15 million km of Earth. It was discovered in 1986, by D. Waldron at Siding Spring Observatory, Coonabarabran, Australia, and named for the first Celtic tribal group that settled in the British Isles.
Two other near-Earth asteroids are known to be currently in resonant states similar to that of Cruithne: 1998 UP1 and 2000 PH5.