 In the domain of the solar planetary disc, there is little variation in the average values of "k" for small bodies at a particular distance from the Sun.If Λ > 1, then the body will likely clear out the small bodies in its orbital zone.Stern and Levison used this discriminant to separate the gravitionally rounded, Sun-orbiting bodies into "überplanets", which are "dynamically important enough to have cleared its neighboring planetesimals", and "unterplanets".