(42355) Typhon Trans-Neptunian Object
Discovered on 5 February 2002 by NEAT at Palomar.
The secondary object (42355) Typhon I, discovered 2006 Jan. 20 by K. Noll, W. Grundy, D. Stephens and H. Levison using the Hubble Space Telescope, is named Echidna for the mother of all the major monsters in classical Greek mythology. Half nymph and half snake, Echidna lives, immortal, in a deep cave called Arima.Naming citation (20061109/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Typhon is today
Seen from above the solar system on 2026-10-14: Typhon is 26.9 au from the Sun and 27.7 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 42355 |
| Provisional designation | 2002 CR46 |
| Orbit class | Trans-Neptunian Object |
| Diameter | 192 km (#35 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0500 |
| Rotation period | 5.00 hours |
| Absolute magnitude (H) | 7.63 |
| Orbital period | 232 years |
| Semi-major axis | 37.8 au |
| Perihelion – aphelion | 17.5 – 58.1 au |
| Eccentricity | 0.537 |
| Inclination | 2.43° |
| Closest distance between its orbit and Earth's (MOID) | 16.5 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.