78P/Gehrels
Comet Gehrels 2 photographed from the Zwicky Transient Facility on 27 January 2019 | |
| Discovery | |
|---|---|
| Discovered by | Tom Gehrels |
| Discovery site | Palomar Observatory, Arizona, USA |
| Discovery date | 29 September 1973 |
| Designations | |
| P/1973 S1, P/1981 L1 | |
| |
| Orbital characteristics | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Observation arc | 52.247 years |
| Number of observations | 8,640 |
| Aphelion | 5.461 AU |
| Perihelion | 2.005 AU |
| Semi-major axis | 3.733 AU |
| Eccentricity | 0.46299 |
| Orbital period | 7.212 years |
| Inclination | 6.257° |
| 210.49° | |
| Argument of periapsis | 192.78° |
| Mean anomaly | 330.47° |
| Last perihelion | 2 April 2019 |
| Next perihelion | 25 June 2026 |
| TJupiter | 2.887 |
| Earth MOID | 1.022 AU |
| Jupiter MOID | 0.024 AU |
| Physical characteristics | |
Mean radius | 4.21 km (2.62 mi) |
| |
| Comet total magnitude (M1) | 9.1 |
| Comet nuclear magnitude (M2) | 12.5 |
78P/Gehrels, also known as Gehrels 2, is a Jupiter-family comet with a current orbital period of 7.22 years. It is the second periodic comet discovered by American astronomer, Tom Gehrels.