Centaurs

Centaurs are small Solar System bodies with a semi-major axis between those of the outer planets. They have unstable orbits that cross or have crossed the orbits of one or more of the giant planets, and have dynamic lifetimes of a few million years. Centaurs typically behave with characteristics of both asteroids and comets. They are named after the mythological race of beings, centaurs, which were a mixture of horse and human. It has been estimated that at the time of the Ascent, there are around 44,000 centaurs in the Solar System with diameters larger than 1 km.

The first centaur to be discovered was 944 Hidalgo in 1920. However, they were not recognized as a distinct population until the discovery of 2060 Chiron in 1977. The largest known centaur is 10199 Chariklo which, at 260 km in diameter, is as big as a mid-sized main-belt asteroid. It was discovered in 1997.

No centaur had been photographed up close prior to the Ascent, although there is evidence that Saturn's moon Phoebe, imaged by the Cassini probe in 2004, may be a captured centaur. In addition, the Hubble Space Telescope had gleaned some information about the surface features of 8405 Asbolus. Later telescopes showed clearer images, but no probe had been sent to them.

B y 2250, most Centaurs larger than 10 km had been claimed, either by groups or companies. As of 5000, it's estimated that up to 1% of the total mass that was once part of the Centaurs has been mined, in some cases entire Centaurs have been consumed by mining.