(311999) 2007 NS2

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2007 NS2
Discovery[1]
Discovery site Observatorio Astronómico de La Sagra
Discovery date July 14, 2007
Designations
Minor planet category Martian L5
Orbital characteristics[2][3]
Epoch April 18, 2013 (JD 2456400.5)
Aphelion 1.6060339 AU
Perihelion 1.4413971 AU
Semi-major axis 1.5237155 AU
Eccentricity 0.0540248
Orbital period 686.9960633 d
1.88 yr
Mean anomaly 225.47063°
Inclination 18.62167°
Longitude of ascending node 282.49888°
Argument of perihelion 176.93881°
Physical characteristics
Dimensions 8001600 m
Absolute magnitude (H) 17.8

    2007 NS2 is an asteroid which orbits the L5 point of Mars.

    Discovery, orbit and physical properties

    2007 NS2 was discovered on July 14, 2007 by the Observatorio Astronómico de La Sagra.[4][5][6][7][8] Its orbit is characterized by low eccentricity (0.054), moderate inclination (18.6º) and a semi-major axis of 1.52 AU.[8] Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. Its orbit is well determined as it is currently (March 2013) based on 87 observations with a data-arc span of 4,800 days.[9] 2007 NS2 has an absolute magnitude of 17.8 which gives a characteristic diameter of 870 m.[9]

    Mars trojan and orbital evolution

    Jean Meeus suspected that 2007 NS2 was a Mars Trojan and this was confirmed by Reiner Stoss’s analysis of two sets of observations dating from 1998 on the MPC database.[10] It was confirmed to be a Mars Trojan numerically in 2012.[11] Recent calculations confirm that it is a stable L5 Mars Trojan asteroid with a libration period of 1310 yr and an amplitude of 14º.[12][13] These values as well as its short-term orbital evolution are similar to those of 5261 Eureka. Out of all known Mars Trojans, it currently has the smallest relative (to Mars) semimajor axis, 0.000059 AU.[12]

    Origin

    Long-term numerical integrations show that its orbit is very stable on Gyr time-scales (1 Gyr = 1 billion years). 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 2007 NS2 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.[12]

    See also

    References

    1. "Major News About Minor Objects". July 16, 2007. Retrieved April 22, 2009. 
    2. "311999 (2007 NS2) orbit diagram". JPL Small-Body Database. Jet Propulsion Laboratory. SPK-ID: 2311999. 
    3. AstDys-1
    4. 2007 NS2 discovery blog
    5. Discovery MPEC
    6. Update MPEC
    7. New Scientist article on the discovery
    8. 8.0 8.1 MPC data on 2007 NS2
    9. 9.0 9.1 JPL's Solar System Dynamics data on 2007 NS2
    10. "Table of contents". Britastro.org. Retrieved 2013-10-29. 
    11. Schwarz, R.; Dvorak, R. (2012). "Trojan capture by terrestrial planets". Celestial Mechanics and Dynamical Astronomy 113 (1): 23. Bibcode:2012CeMDA.113...23S. doi:10.1007/s10569-012-9404-4. 
    12. 12.0 12.1 12.2 de la Fuente Marcos, C.; de la Fuente Marcos, R. (2013). "Three new stable L5 Mars Trojans". Monthly Notices of the Royal Astronomical Society Letters 432 (1): L31–L35. arXiv:1303.0124. Bibcode:2013MNRAS.432L..31D. doi:10.1093/mnrasl/slt028. 
    13. Christou, A. A. (2013). "Orbital clustering of Martian Trojans: An asteroid family in the inner solar system?". Icarus 224 (1): 144–153. arXiv:1303.0420. Bibcode:2013Icar..224..144C. doi:10.1016/j.icarus.2013.02.013. 
    Further reading

    External links

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