List of fast rotators (minor planets)
This is a list of fast rotators—"minor planets" that have an exceptionally short rotation period, i.e. high rotation rate or spin rate. In some cases the rotation period is not constant because the object tumbles. In this list the periods are sourced from the Light Curve Data Base, and are given in both seconds and hours.
Most minor planets have rotation periods between 2 and 20 hours., a group of 887 bodies – most of them were stony near-Earth asteroids with small diameters of barely 1 kilometre – had an estimated period of less than 2.2 hours. According to the Minor Planet Center, most small bodies were thought to be rubble piles – conglomerations of smaller pieces, loosely coalesced under the influence of gravity. Bodies with a period below 2.2 hours – known as the "cohesionless spin-barrier" – couldn't be merely held together by self-gravity, but must be formed of a contiguous solid, as they would fly apart otherwise. Via the deduction of strength boundary limits, rotation periods give an insight into the body's internal composition, and, from its degree of fracture, its collisional history can be inferred.
Bodies with an uncertain period are displayed in dark-grey. They have an Asteroid Lightcurve Database (LCDB) quality code, U, of less than 2, which corresponds to an estimated error margin of larger than 30%. A trailing plus sign or minus sign indicate slightly better or worse quality, respectively, than the unsigned value. This list also includes a small group of bodies which have no provisional designation in the LCDB.