(311999) 2007 NS2 is an asteroid and Mars trojan orbiting near the L5 point of Mars.

(311999) 2007 NS2
Discovery[1]
Discovery siteObservatorio Astronómico de La Sagra
Discovery date14 July 2007
Designations
Martian L5 Martian L5
Orbital characteristics[2][3]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc6296 days (17.24 yr)
Aphelion1.6061055 AU (240.26996 Gm)
Perihelion1.4414495 AU (215.63778 Gm)
1.5237775 AU (227.95387 Gm)
Eccentricity0.0540289
1.88 yr (687.04 d)
29.476921°
0.5239885°/day
Inclination18.62037°
282.49476°
176.94930°
Physical characteristics
Dimensions800–1600 m
18.1

Discovery, orbit and physical properties

edit

(311999) 2007 NS2 was discovered on 14 July 2007, by the Observatorio Astronómico de La Sagra.[4][5][6][7][8] Its orbit is characterized by low eccentricity (0.054), moderate inclination (18.6°) 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.[2] 2007 NS2 has an absolute magnitude of 17.8, which gives a characteristic diameter of 870 m.[2]

Mars trojan and orbital evolution

edit

Jean Meeus suspected that (311999) 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.[9] It was confirmed to be a Mars Trojan numerically in 2012.[10] Recent calculations confirm that it is a stable L5 Mars Trojan asteroid with a libration period of 1310 years and an amplitude of 14°.[11][12] 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.[11]

Origin

edit

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 (311999) 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.[11]

 
Animation of 2007 NS2 relative to Sun and Mars 1600-2500
   Sun ·   2007 NS2 ·   Mars

See also

edit

References

edit
  1. ^ "Major News About Minor Objects". 16 July 2007. Archived from the original on 6 August 2019. Retrieved 22 April 2009.
  2. ^ a b c "311999 (2007 NS2) orbit diagram". JPL Small-Body Database. Jet Propulsion Laboratory. SPK-ID: 2311999. Retrieved 28 March 2016.
  3. ^ AstDys-1
  4. ^ 2007 NS2 discovery blog
  5. ^ Discovery MPEC
  6. ^ Update MPEC
  7. ^ New Scientist article on the discovery
  8. ^ a b MPC data on 2007 NS2
  9. ^ "Table of contents". Britastro.org. Retrieved 29 October 2013.
  10. ^ Schwarz, R.; Dvorak, R. (2012). "Trojan capture by terrestrial planets". Celestial Mechanics and Dynamical Astronomy. 113 (1): 23. arXiv:1611.07413. Bibcode:2012CeMDA.113...23S. doi:10.1007/s10569-012-9404-4. S2CID 254375599.
  11. ^ a b c de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (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.
  12. ^ 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. S2CID 119186791.

Further reading

edit
edit