26P/Grigg–Skjellerup
Comet Grigg–Skjellerup photographed from the European Southern Observatory on 29 June 1992 | |
| Discovery | |
|---|---|
| Discovered by | John Grigg John Francis Skjellerup |
| Discovery date | 23 July 1902 17 May 1922 |
| Designations | |
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| Orbital characteristics | |
| Epoch | 17 October 2024 (JD 2460600.5) |
| Observation arc | 216.67 years |
| Earliest precovery date | 6 February 1808 |
| Number of observations | 827 |
| Aphelion | 4.947 AU |
| Perihelion | 1.084 AU |
| Semi-major axis | 3.015 AU |
| Eccentricity | 0.64056 |
| Orbital period | 5.236 years |
| Max. orbital speed | 36.6 km/s |
| Inclination | 22.433° |
| 211.54° | |
| Argument of periapsis | 2.136° |
| Mean anomaly | 55.845° |
| Last perihelion | 25 December 2023 |
| Next perihelion | 18 March 2029 |
| TJupiter | 2.804 |
| Earth MOID | 0.085 AU |
| Jupiter MOID | 0.006 AU |
| Physical characteristics | |
Mean radius | 1.3 km (0.81 mi) |
| 12 hours | |
| (V–R) = 0.42±0.10 | |
| Comet total magnitude (M1) | 16.5 |
Comet Grigg–Skjellerup (formally designated 26P/Grigg–Skjellerup) is a periodic comet. It was visited by the Giotto probe in July 1992. The spacecraft came as close as 200 km, but could not take pictures because some instruments were damaged from its encounter with Halley's Comet. The comet last came to perihelion (closest approach to the Sun) on 25 December 2023, but was 1.8 AU from Earth and only 31 degrees from the Sun.