2018 EC4 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).[2]

2018 EC4
Discovery
Discovered byMt. Lemmon Survey
Discovery date10 March 2018
Designations
2018 EC4
Martian L5 Martian L5
Orbital characteristics[1]
Epoch 31 May 2020 (JD 2459500.5)
Uncertainty parameter 0
Observation arc3131 days (8.57 yr)
Aphelion1.61579336 AU (241.719246 Gm)
Perihelion1.43135923 AU (214.128293 Gm)
1.52357630 AU (227.923770 Gm)
Eccentricity0.06052671
1.88 yr (686.90193 d)
203.4934°
0° 31m 26.732s /day
Inclination21.835796°
47.371564°
344.1754°
Earth MOID0.443437 AU (66.3372 Gm)
Jupiter MOID3.54199 AU (529.874 Gm)
Physical characteristics
Dimensions300 m
0.5-0.05 (assumed)
20.1

Discovery, orbit and physical properties

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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

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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

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L4 (leading):

L5 (trailing):

See also

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References

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  1. ^ a b c "JPL Small-Body Database Browser: (2018 EC4)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
  2. ^ 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.
  3. ^ a b MPC data on 2018 EC4

Further reading

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