Damocloid family

The Damocloid family is an unusual collection of asteroids with highly elliptical and, sometimes, highly inclined orbits that resemble those of short-period comets. Because of this similarity, it is thought that Damocloids may be the dark remains of old comets. The prototype of the group, 5335 Damocles, was discovered in 1991 by Robert McNaught (1956–) at the Anglo-Australian Observatory and named for a courtier of the ancient tyrant Dionysus I (The Elder) of Syracuse who lived in the 4th century BC. Another suspected Damocloid, asteroid 2001 OG108, discovered in July 2001, has an orbit that takes it from just inside Earth's orbit out as far as Uranus. If its estimated diameter of 15 km is correct, this would make it one of the biggest Earth-crossing asteroids known.


Data for 5335 Damocles
diameter 15 to 20 km
semimajor axis 11.88 AU
perihelion 1.58 AU
aphelion 22.18 AU
inclination 61.9°
period 40.6 years