| Discovery | |
|---|---|
| Discovered by | Leo Boethin |
| Discovery date | January 4, 1975 |
| Designations | |
| D/1975 A1; 85P/1975 A1; 1975 I; 1975a; 85P/1985 T2; 1986 I; 1985n | |
| Orbital characteristics | |
| Epoch | 1 June 2007 (JD 2454252.5) |
| Observation arc | 4042 days (11.07 yr) |
| Number of observations | 51 |
| Aphelion | 9.23512 AU |
| Perihelion | 1.13466 AU |
| Semi-major axis | 5.18489 AU |
| Eccentricity | 0.78116 |
| Orbital period | 11.81 a |
| Inclination | 4.295° |
| 37.618° | |
| Argument of periapsis | 359.396° |
| Last perihelion | 2020-Jul-29?[1] December 16, 2008[2] (unobserved) |
| Next perihelion | 2031-Nov-30?[3] (lost since 1986) |
| TJupiter | 2.247 |
| Earth MOID | 0.1499 AU |
| Jupiter MOID | 0.1307 AU[4] |
Comet Boethin (officially 85D/Boethin) was a periodic Jupiter-family comet discovered in 1975 by Leo Boethin. It appeared again in January 1986 as expected. Although the comet was next expected at perihelion in April 1997, no observations were reported, and the comet is thought to have disintegrated. It has not been observed since March 1986.[1] The comet might have come to perihelion in late July 2020, but the uncertainty in the comet's position is hundreds of millions of km. The old orbit would have the comet next coming to perihelion around November 2031.