If the asteroid was discovered in 1986, why wasn the unusual nature of its orbit noticed earlier?
The interaction of Cruithne with the Earth is unusual, and takes place over several hundred years. Because of this, fairly long and careful simulations of its orbit are required to make its true nature clear. In addition, there are more technical reasons: the asteroid’s high inclination (20 degrees) and eccentricity (0.51) seemed to make it a very unlikely candidate for such a delicate relationship with the Earth, as horseshoe orbits had previously only been thought possible if an asteroid was on an orbit with a very low eccentricity and inclination. • Does asteroid 3753 Cruithne orbit the Earth like a moon or satellite? No. The asteroid’s behaviour is more complicated than that: it doesn’t orbit the Earth, but rather it shares the Earth’s orbit. The relationship of a moon to its planet is called a two-body because there are only two important players (ie. the moon and the planet). However, in the case of Cruithne, the Earth and the asteroid both share the same orbit about the Sun, but
