210P/Christensen
Comet 210P/Christensen imaged from an 8-in reflector on 1 December 2025 | |
| Discovery[1] | |
|---|---|
| Discovered by | Eric J. Christensen |
| Discovery site | Catalina Sky Survey |
| Discovery date | 26 May 2003 |
| Designations | |
| P/2003 K2, P/2008 X4 | |
| Orbital characteristics[3][4] | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Observation arc | 22.35 years |
| Number of observations | 947 |
| Aphelion | 5.797 AU |
| Perihelion | 0.524 AU |
| Semi-major axis | 3.161 AU |
| Eccentricity | 0.83408 |
| Orbital period | 5.619 years |
| Inclination | 10.287° |
| 93.797° | |
| Argument of periapsis | 345.95° |
| Mean anomaly | 359.69° |
| Last perihelion | 22 November 2025 7 April 2020 |
| Next perihelion | 6 July 2031[2] |
| TJupiter | 2.492 |
| Earth MOID | 0.170 AU |
| Jupiter MOID | 0.019 AU |
| Physical characteristics[3] | |
| Dimensions | 0.87 km (0.54 mi)[5] |
| Comet total magnitude (M1) | 14.9 |
210P/Christensen is a Jupiter family 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.[6]
Observational history
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.[7]
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.[6] Maik Meyer noticed the similarity of these orbital elements to those of P/2003 K2 and the link was confirmed by Brian G. Marsden.[6][8] This was the first recovery of a single-apparition comet by a spacecraft.[6] The comet was observed from the ground on 14 December 2008, located low and in bright twilight, and on 31 December 2008 it had an estimated magnitude of 10.5.[9]
During the 2025 apparition, the comet passed 0.43 AU (64 million km; 40 million mi) from Earth on 8 November 2025 but was only 20 degrees from the Sun.[10] It came to perihelion on 22 November 2025. It was visible in SWAN in November 2025 around magnitude 11. On 26 November it was visible low in the morning twilight, with a faint tail about a quarter of a degree long and an estimated magnitude of 9.5.[11]
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.[5] Its nucleus is estimated to be about 1.74 km (1.08 mi) in diameter.[5] It makes close approaches to Venus and on 17 September 1929 passed 0.032 AU (4.8 million km; 3.0 million mi) from Venus.[3]
References
- ^ a b c E. J. Christensen; R. Elliot; P. R. Holvorcem (27 May 2003). D. W. Green (ed.). "Comet C/2003 K2". IAU Circular. 8136 (1). Bibcode:2003IAUC.8136....1C.
- ^ "Horizons Batch for 210P/Christensen on 2031-Jul-06" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 14 December 2025. (Soln.date: 2025-Dec-03)
- ^ a b c "210P/Christensen – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 20 July 2023.
- ^ "210P/Christensen Orbit". Minor Planet Center. Retrieved 20 October 2025.
- ^ a b c J. A. Fernández; A. Sosa (2015). "Jupiter family comets in near-Earth orbits: Are some of them interlopers from the asteroid belt?". Planetary & Space Science. 118: 14–24. Bibcode:2015P&SS..118...14F. doi:10.1016/j.pss.2015.07.010.
- ^ a b c d A. Patel (17 December 2008). "SECCHI Makes a Fantastic Recovery!". stereo.gsfc.nasa.gov. NASA / GSFC. Retrieved 12 December 2023.
- ^ D. W. Green (7 June 2003). "Comet P/2003 K2 (Christensen)". IAU Circular. 8145 (2). Bibcode:2003IAUC.8145....2G.
- ^ K. Battams; A. Watson; R. Kracht; M. Meyer; B. G. Marsden (December 2008). D. W. Green (ed.). "Comet P/2008 X4 = P/2003 K2 (Christensen)". IAU Circular. 9005 (1). Bibcode:2008IAUC.9005....1B.
- ^ K. Kadota; B. G. Marsden (January 2009). D. W. Green (ed.). "Comet P/2008 X4 (Christensen)". IAU Circular. 9008 (2). Bibcode:2009IAUC.9008....2K.
- ^ "Earth approach on 2025-Nov-08". JPL Horizons. Retrieved 14 December 2025.
- ^ Olason, Mike (27 November 2025). "Bright Comet 210P/Christensen". Sky & Telescope. Retrieved 4 December 2025.
External links
- 210P/Christensen at the JPL Small-Body Database
- 210P/Christensen at Seiichi Yoshida's website
- 210P at COBS