2011 SP189
Asteroid
From Wikipedia, the free encyclopedia
2011 SP189 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).[2][3][4]
| Discovery | |
|---|---|
| Discovered by | Mt. Lemmon Survey |
| Discovery date | 29 September 2011 |
| Designations | |
| 2011 SP189 | |
| Martian L5 | |
| Orbital characteristics[1] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 2390 days (6.54 yr) |
| Aphelion | 1.5852549 AU (237.15076 Gm) |
| Perihelion | 1.462275 AU (218.7532 Gm) |
| 1.5237649 AU (227.95198 Gm) | |
| Eccentricity | 0.040354 |
| 1.88 yr (687.0295 d) | |
| 110.302° | |
| 0° 31m 26.382s /day | |
| Inclination | 19.89778° |
| 0.663826° | |
| 122.545° | |
| Earth MOID | 0.490971 AU (73.4482 Gm) |
| Jupiter MOID | 3.40399 AU (509.230 Gm) |
| Physical characteristics | |
| 300 m | |
| 0.5-0.05 (assumed) | |
| 20.9 | |
Discovery, orbit and physical properties
2011 SP189 was first observed on 29 September 2011 by the Mount Lemmon Survey.[5] Its orbit is characterized by low eccentricity (0.040), moderate inclination (19.9°) and a semi-major axis of 1.52 AU.[5] Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. It is now classified as a Mars trojan. Its orbit is well determined as it is currently (January 2021) based on 45 observations with a data-arc span of 2390 days.[1] 2011 SP189 has an absolute magnitude of 20.9 which gives a characteristic diameter of 300 m.[1]
Mars trojan and orbital evolution
Recent calculations indicate that it is a stable L5 Mars trojan with a libration period of 1300 yr and an amplitude of 20°.[2] These values are similar to those of 5261 Eureka and related objects and it may be a member of the so-called Eureka family.
