| 210P/Christensen | |
| Discovery Ref: | [1] |
| Discoverer: | Eric J. Christensen |
| Discovery Date: | 26 May 2003 |
| Designations: | P/2003 K2, P/2008 X4 |
| Orbit Ref: | [2] |
| Epoch: | 3 February 2010 |
| Aphelion: | 5.817 AU |
| Perihelion: | 0.534 AU |
| Semimajor: | 3.176 AU |
| Eccentricity: | 0.8317 |
| Period: | 5.659 years |
| Inclination: | 10.217° |
| Asc Node: | 93.872° |
| Arg Peri: | 345.766° |
| Tjup: | 2.492 |
| Earth Moid: | 0.170 AU |
| Jupiter Moid: | 0.018 AU |
| Dimensions: | ≤ 1.74 km[3] |
| M1: | 14.9 |
| Last P: | 7 April 2020 |
| Next P: | 22 November 2025 [4] |
210P/Christensen is a Jupiter family periodic comet with an orbital period of 5.7 years. It was discovered by Eric J. Christensen on 26 May 2003 in images taken by the Catalina Sky Survey[1] and recovered in images obtained by STEREO, the first time a single-apparition comet was recovered by a spacecraft.[5]
Eric J. Christensen discovered the comet on 26 May 2003 in images taken with the 0.7-m Schmidt telescope of the Catalina Sky Survey. The comet had an estimated magnitude of 14.6 and a coma with an estimated diameter between 10 and 35 arcseconds and a faint tail.[1] Further observations revealed the comet had a short orbital period.[6]
In mid December 2008, Australian comet-hunter Alan Watson spotted in the STEREO/SECCHI Heliospheric Imager ("HI") HI-1B data a cometary object. Veteran German comet hunter Rainer Kracht recorded a few positions of the comet in the data and produced a set of very approximate orbital elements for it.[5] Maik Meyer noticed the similarity of these orbital elements to those of P/2003 K2 and the link was confirmed by Brian Marsden.[5] [7] This was the first recovery by a spacecraft of a single-apparition comet (a comet that had only been observed to pass the Sun once) by a spacecraft.[5] The comet was observed from the ground on 31 November 2008, with an estimated magnitude of 11.[8]
The comet has been locked in a 2:1 orbital resonance with Jupiter for the last 10,000 years and could be of asteroidal origin.[3]