73P/Schwassmann–Wachmann
| Discovery | |
|---|---|
| Discovered by | Arnold Schwassmann Arno Arthur Wachmann |
| Discovery date | May 2, 1930 |
| Designations | |
| 1930 VI; 1979 VIII; 1990 VIII; 1994w | |
| Orbital characteristics | |
| Epoch | 2017-Feb-16 (JD 2457800.5) |
| Aphelion | 5.211 AU |
| Perihelion | 0.9722 AU (0.9187 AU after 2025 Jupiter approach) |
| Semi-major axis | 3.092 AU |
| Eccentricity | 0.6855 |
| Orbital period | 5.44 yr |
| Inclination | 11.237° |
| Last perihelion | 24 August 2022 (BU+BV) 25 August 2022 (main) 26 August 2022 (73P-BT) |
| Next perihelion | 23 December 2027 |
| Earth MOID | 0.014 AU (2.1 million km) |
| Physical characteristics | |
| Dimensions | 2.2 km (pre-1995 breakup) ~1 km (73P-C) |
73P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 3 or SW3 for short, is a periodic comet that has a 5.4 year orbital period and that has been actively disintegrating since 1995. When it came to perihelion (closest approach to the Sun) in March 2017, fragment 73P-BT was separating from the main fragment 73P-C. Fragments 73P-BU and 73P-BV were detected in July 2022. The main comet came to perihelion on 25 August 2022, when the comet was 0.97 AU from the Sun and 1 AU from Earth. It will be less than 80 degrees from the Sun from 25 May 2022 until August 2023. On 3 April 2025 it made a modest approach of 0.3 AU to Jupiter. 73P will next come to perihelion on 23 December 2027 when it will be 0.92 AU from the Sun and on the far side of the Sun 1.9 AU from Earth.