| Discovery | |
|---|---|
| Discovered by | Pan-STARRS |
| Discovery site | Haleakala Obs. |
| Discovery date | 25 September 2017 (first observation only) |
| Designations | |
| Mars crosser | |
| Orbital characteristics | |
| Epoch 25 September 2017 (JD 2458021.5) | |
| Uncertainty parameter 9 | |
| Observation arc | 2 days |
| Aphelion | 3.174±0.115 AU |
| Perihelion | 1.322±0.011 AU |
| 2.248±0.081 AU | |
| Eccentricity | 0.4120±0.0165 |
| 3.37±0.18 years | |
| 359.260°±0.686° | |
| 0° 17m 32.712s / day | |
| Inclination | 6.029°±0.200° |
| 187.923°±0.130° | |
| 173.329°±1.838° | |
| Earth MOID | 0.3187 AU (120 LD) |
| Physical characteristics | |
| |
| 23.85±0.14 | |
2017 SG33 is a Mars-crossing asteroid that was previously thought to be a near-Earth object. It was first observed on 25 September 2017, when the asteroid was less than 1 AU from Earth and had a solar elongation of 169°. This asteroid had an observation arc of 2 days and was previously a lost asteroid.
This asteroid was previously in the Risk List and the Priority List of the European Space Agency (ESA) - Space Situational Awareness (SSA). The asteroid was also in the Sentry List of the Jet Propulsion Laboratory (JPL) - Center for Near Earth Object Studies (CNEOS). According to the Sentry List at the time, of the possible close encounters with Earth in the foreseeable future, an encounter on 8 September 2051 had the highest risk of impact. Recalculations of the orbit of 2017 SG33 from additional observations showed that it does not make any close approaches to Earth, which led to its removal from the Sentry List on 29 July 2021.