42355 Typhon is a scattered disc

Scattered disc

The scattered disc is a distant region of the Solar System that is sparsely populated by icy minor planets, a subset of the broader family of trans-Neptunian objects. The scattered-disc objects have orbital eccentricities ranging as high as 0.8, inclinations as high as 40°, and perihelia greater...

 object that was discovered on February 5, 2002, by the NEAT

Near Earth Asteroid Tracking

Near-Earth Asteroid Tracking is a program run by NASA and Jet Propulsion Laboratory to discover near-Earth objects. The NEAT project began in December 1995 and ran until April 2007.-History:...

 program. It measures 134±13 km in diameter, and is named after Typhon

Typhon

Typhon , also Typhoeus , Typhaon or Typhos was the last son of Gaia, fathered by Tartarus, and the most deadly monster of Greek mythology. He was known as the "Father of all monsters"; his wife Echidna was likewise the "Mother of All Monsters."Typhon was described in pseudo-Apollodorus,...

, a monster in Greek mythology

Greek mythology

Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...

.

A large moon

Asteroid moon

A minor planet moon is an astronomical body that orbits a minor planet as its natural satellite. It is thought that many asteroids and Kuiper belt objects may possess moons, in some cases quite substantial in size...

 was identified in 2006. It is named Echidna—formal designation (42355) Typhon I Echidna, , from —after Echidna

Echidna (mythology)

In Greek mythology, Echidna was half woman half snake, known as the "Mother of All Monsters" because most of the monsters in Greek myth were mothered by her...

, the monstous mate of Typhon. It orbits Typhon at ~1300 km, completing one orbit in about 11 days. Its diameter is estimated to be 78±8 km. Typhon is considered the first known binary centaur, using an extended definition of a centaur as an object on a non-resonant (unstable) orbit with the perihelion inside the orbit of Neptune.