Commonality
The data about the populations of binary objects are still patchy. In addition to the inevitable observational bias (dependence on the distance from Earth, size, albedo and separation of the components) the frequency appears to be different among different categories of objects. Among asteroids, an estimated 2% would have satellites. Among trans-Neptunian objects (TNO), an estimated 11% are believed to be binary or multiple objects, but three of the four known large TNO (75%) have at least one satellite.
More than 20 binaries are known in each of the main groupings: near-Earth asteroids, main-belt asteroids, and trans-Neptunians, not including numerous claims based solely on light-curve variation.
No binaries have been found so far among centaurs with semi-major axis smaller than Neptune. However, using an extended definition of Centaurs, as the objects on unstable orbits with the perihelion inside the orbit of Neptune, the first binary centaur, 42355 Typhon (previously known as 2002 CR46), was identified in 2006.
Read more about this topic: Minor-planet Moon