2018 EC4
| Discovery | |
|---|---|
| Discovered by | Mt. Lemmon Survey |
| Discovery date | 10 March 2018 |
| Designations | |
| 2018 EC4 | |
Martian L5  | |
| Orbital characteristics[1] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 3131 days (8.57 yr) |
| Aphelion | 1.61579336 AU (241.719246 Gm) |
| Perihelion | 1.43135923 AU (214.128293 Gm) |
| 1.52357630 AU (227.923770 Gm) | |
| Eccentricity | 0.06052671 |
| 1.88 yr (686.90193 d) | |
| 203.4934° | |
| 0° 31m 26.732s /day | |
| Inclination | 21.835796° |
| 47.371564° | |
| 344.1754° | |
| Earth MOID | 0.443437 AU (66.3372 Gm) |
| Jupiter MOID | 3.54199 AU (529.874 Gm) |
| Physical characteristics | |
| Dimensions | 300 m |
| 0.5-0.05 (assumed) | |
| 20.1 | |
2018 EC4 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).[2]
Discovery, orbit and physical properties
[edit]2018 EC4 was first observed on 10 March 2018 by the Mt. Lemmon Survey, but it had already been imaged (but not identified as an asteroid) by the Pan-STARRS 1 telescope system at Haleakala on 29 October 2011.[3] Its orbit is characterized by low eccentricity (0.061), moderate inclination (21.8°) and a semi-major axis of 1.52 AU.[3] Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. Its orbit is well determined as it is currently (January 2021) based on 70 observations with a data-arc span of 3,131 days.[1] 2018 EC4 has an absolute magnitude of 20.1 which gives a characteristic diameter of 300 m.[1]
Mars trojan and orbital evolution
[edit]Recent calculations indicate that it is a stable L5 Mars trojan with a libration period of 1250 yr and an amplitude of 17°.[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.[citation needed]
Mars trojan
[edit]L4 (leading):
L5 (trailing):
- 5261 Eureka (1990 MB) †
- (101429) 1998 VF31 †
- (311999) 2007 NS2 †
- (385250) 2001 DH47
- 2009 SE
- 2011 SC191
- 2011 SL25
- 2011 SP189
- 2011 UB256
- 2011 UN63
- 2016 CP31
- 2018 EC4
- 2018 FC4
See also
[edit]References
[edit]- ^ a b c "JPL Small-Body Database Browser: (2018 EC4)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
- ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (March 2021). "Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space". Monthly Notices of the Royal Astronomical Society. 501 (4): 6007–6025. arXiv:2101.02563. Bibcode:2021MNRAS.501.6007D. doi:10.1093/mnras/stab062.
- ^ a b MPC data on 2018 EC4
Further reading
[edit]- Three new stable L5 Mars Trojans de la Fuente Marcos, C., de la Fuente Marcos, R. 2013, Monthly Notices of the Royal Astronomical Society: Letters, Vol. 432, Issue 1, pp. 31–35.
- Orbital clustering of Martian Trojans: An asteroid family in the inner solar system? Christou, A. A. 2013, Icarus, Vol. 224, Issue 1, pp. 144–153.
External links
[edit]- 2018 EC4 data at MPC.
- 2018 EC4 at AstDyS-2, Asteroids—Dynamic Site
- 2018 EC4 at the JPL Small-Body Database
