7P/Pons–Winnecke (also known as Comet Pons–Winnecke) is a periodic Jupiter-family comet with a six-year orbit. Early calculations for the 1921 apparition suggested that the orbit of the comet might collide with Earth in June, but observations on 10 April ruled out an impact.[6] It made a very close approach to Earth in June 1927.[7] The outward migration of perihelion created impressive meteor showers in 1916, 1921 and 1927.[8]
 Comet Pons–Winnecke as seen in 2021 by ZTF | |
| Discovery | |
|---|---|
| Discovered by | Jean Louis Pons & Friedrich Winnecke |
| Discovery date | June 12, 1819 & March 9, 1858 |
| Designations | |
| 1858 E1, 1858 II, 1819 III, 1927c, 1933b, 1939c, 1945a, 1951c, 1964b, 1970b, 1976f, 1983b, 1989g | |
| Orbital characteristics | |
| Epoch | 2023-02-25[1] |
| Aphelion | 5.59 AU |
| Perihelion | 1.233 AU |
| Semi-major axis | 3.41 AU |
| Eccentricity | 0.6385 |
| Orbital period | 6.30 yrs |
| Inclination | 22.373° |
| Last perihelion | May 27, 2021[1] January 30, 2015[2] September 26, 2008 |
| Next perihelion | 2027-Aug-25[3][4] |
| Earth MOID | 0.24 AU (36 million km) |
| Physical characteristics | |
| Dimensions | 5.2 km[5] |
| Perihelion distance at different epochs[4] | |||||||
| Epoch | Perihelion (AU) | ||||||
|---|---|---|---|---|---|---|---|
| 1819 | 0.77 | ||||||
| 1875 | 0.83 | ||||||
| 1886 | 0.89 | ||||||
| 1898 | 0.92 | ||||||
| 1909 | 0.97 | ||||||
| 1921 | 1.04 | ||||||
| 1933 | 1.10 | ||||||
| 1989 | 1.26 | ||||||
| 2027 | 1.13 | ||||||
| 2039 | 0.982 | ||||||
| 2062 | 0.847 | ||||||
The next perihelion passage is 25 August 2027[3] when the comet will have a solar elongation of 63 degrees. The last perihelion passage was 27 May 2021 when the comet had a solar elongation of 107 degrees at approximately apparent magnitude 11.[2] It passed 0.44 AU (66 million km) from Earth on 12 June 2021. Before that it came to perihelion on 30 January 2015[2] with a solar elongation of 24 degrees.[9]
Jean Louis Pons (Marseille) originally discovered the comet on 12 June 1819, it was later rediscovered by Friedrich August Theodor Winnecke (Bonn) on 9 March 1858. It is the parent body of the June Bootids of late June.
7P has an orbital period of 6.3 years. It currently has a perihelion of 1.2 AU (outside the orbit of Earth) and an aphelion of 5.6 AU (past the orbit of Jupiter). It passed within 0.04 AU (6.0 million km; 16 LD) of Earth in June 1927, and 0.1 AU (15 million km) in 1939;[5] but it will not come as close in the 21st century. A close approach to Jupiter in July 2037[5] will drop perihelion to 0.982 AU, and by 2062 perihelion will be further reduced to 0.85 AU.[4]
| Date & time of closest approach | Earth distance (AU) | Sun distance (AU) | Velocity wrt Earth (km/s) | Velocity wrt Sun (km/s) | Uncertainty region (3-sigma) | Reference |
|---|---|---|---|---|---|---|
| 2062-Jun-12 18:25 ± 10 min | 0.1676 AU (25.07 million km; 15.58 million mi; 65.2 LD) | 0.8499 AU (127.14 million km; 79.00 million mi; 330.8 LD) | 16.3 | 42.5 | ± 312 km | Horizons |
The comet nucleus is estimated at 5.2 km in diameter.[5]
Proposed exploration
The Jet Propulsion Laboratory proposed a flyby of the comet with a flight spare of Mariner 4 with the closest approach taking place in 1969.[10] The probe was instead used for a Venus flyby as Mariner 5.[10]
References
External links
- Orbital simulation from JPL (Java) / Horizons Ephemeris
- Elements and Ephemeris for 7P/Pons-Winnecke – Minor Planet Center
- 7P/Pons-Winnecke – Seiichi Yoshida @ aerith.net
- 7P – Gary W. Kronk's Cometography
- article on the nuclei of 7P, 14P, and 92P