| 143P/Kowal–Mrkos | |
| Discoverer: | Charles T. Kowal Antonín Mrkos |
| Discovery Date: | April 23, 1984 |
| Designations: | 1984 JD; 1984 X; 2000 ET90 |
| Epoch: | March 6, 2006 |
| Jupiter Moid: | 0.0196AU |
| Semimajor: | 4.306 AU |
| Perihelion: | 2.538 AU |
| Aphelion: | 6.074 AU |
| Eccentricity: | 0.4106 |
| Period: | 8.935 a |
| Inclination: | 4.6896° |
| Last P: | May 7, 2018[1] June 12, 2009 |
| Next P: | 2026-Dec-28[2] |
143P/Kowal–Mrkos is a periodic comet in the Solar System.