| Minorplanet: | yes |
| Background: |
|
| Discoverer: | Spacewatch |
| Discovered: | 20 February 2001 |
| Mpc Name: | (385250) |
| Epoch: | 13 January 2016 (JD 2457400.5) |
| Observation Arc: | 5521 days (15.12 yr) |
| Uncertainty: | 0 |
| Aphelion: | 1.5767436abbr=onNaNabbr=on |
| Perihelion: | 1.4708966AU |
| Semimajor: | 1.5238201AU |
| Eccentricity: | 0.0347308 |
| Period: | 1.88 yr (687.07 d) |
| Inclination: | 24.40220° |
| Asc Node: | 147.42225° |
| Mean Anomaly: | 322.37107° |
| Mean Motion: | / day |
| Arg Peri: | 17.54935° |
| Mean Diameter: | 0.562 km |
| Rotation: | 3.97 h |
| Albedo: | 0.5–0.05 (assumed) |
| Abs Magnitude: | 18.9 |
, provisional designation, is a sub-kilometer asteroid and Mars trojan orbiting 60° behind the orbit of Mars near the .[1] [2]
was discovered on 1 February 2001 by the Spacewatch program, observing from Steward Observatory, Kitt Peak and classified as Mars-crosser by the Minor Planet Center. Its orbit is characterized by low eccentricity (0.035), moderate inclination (24.4º) and a semi-major axis of 1.52 AU.[3] Its orbit is well determined as it is currently (March 2013) based on 45 observations with a data-arc span of 3,148 days.[4] It has an absolute magnitude of 19.7 which gives a characteristic diameter of 562 m.[4]
It was identified as Mars trojan by H. Scholl, F. Marzari and P. Tricarico in 2005 and its dynamical half-lifetime was found to be of the order of the age of the Solar System.[1] Recent calculations[2] confirm that it is indeed a stable Mars trojan with a libration period of 1365 yr and an amplitude of 11°. These values as well as its short-term orbital evolution are very similar to those of 5261 Eureka.
Long-term numerical integrations show that its orbit is very stable on Gyr time-scales (1 Gyr = 1 billion years).[1] [2] As in the case of Eureka, calculations in both directions of time (4.5 Gyr into the past and 4.5 Gyr into the future) indicate that may be a primordial object, perhaps a survivor of the planetesimal population that formed in the terrestrial planets region early in the history of the Solar System.[2]