Open main menu

2011 EO40 is an asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It is a possible candidate for the parent body of the Chelyabinsk superbolide.[7][8][9]

2011 EO40
Discovered byRichard A. Kowalski
(Mount Lemmon Survey)
Discovery dateMarch 10, 2011
MPC designation2011 EO40
Apollo NEO PHA,[2][3][4]
Earth crosser
Orbital characteristics[3][5]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 6
Aphelion2.5479 AU (381.16 Gm)
Perihelion0.76042 AU (113.757 Gm)
1.6542 AU (247.46 Gm)
2.13 yr (777.10 d)
0° 27m 47.736s /day
Earth MOID0.0482051 AU (7.21138 Gm)
Jupiter MOID2.79322 AU (417.860 Gm)
Physical characteristics
Dimensions150-330 m[a][6]

Discovery, orbit and physical propertiesEdit

2011 EO40 was discovered by Richard A. Kowalski on March 10, 2011 while observing for the Mount Lemmon Survey.[1][10]

Its orbit is typical of Apollo asteroids and is characterized by significant eccentricity (0.54), low inclination (3.36º), and a semi-major axis of 1.65 AU.[10] Upon discovery, it was classified as an Earth crosser, a near-Earth asteroid (NEA) and a potentially hazardous asteroid (PHA) by the Minor Planet Center. It was listed on the Sentry Risk Table for less than one day.[11] Its orbit is in need of additional observations to determine if it is part of an asteroid family; as of October 2015 the orbit is determined using just twenty observations spanning an observation arc of 34 days.[3] 2011 EO40 has an absolute magnitude of 21.5,[3] which gives a characteristic diameter of about 200 metres (660 ft).[6]

Relationship to the Chelyabinsk superbolideEdit

Recent calculations indicate that this object is a plausible candidate to be the parent body of the Chelyabinsk superbolide, since its orbit is very similar to the computed, pre-impact path of the Chelyabinsk meteoroid.[7][8][9] It has relatively frequent close encounters with Venus, the EarthMoon system, and Mars. It had a close encounter with Earth on January 28, 2011 at 0.0953 AU (14,260,000 km; 8,860,000 mi),[3] and it will have a nominal Earth approach on September 23, 2025 at around 0.06 AU (9,000,000 km; 5,600,000 mi).[3] Asteroid 2011 EO40 experiences close approaches to the Earth–Moon system following a rather regular pattern, every 17 years approximately due to the combined action of multiple secular resonances.[8]


Future opposition windows are: June 7, 2016 at magnitude 24.5, and May 28, 2018 at magnitude 24.6. The best observation window will be on September 2–23, 2025.[3] Depending on the Earth approach distance (0.04–0.12 AU),[3] it should be brighter than magnitude 19.[12]

See alsoEdit


  • ^ This is assuming an albedo of 0.20–0.04.


  1. ^ a b Discovery MPEC
  2. ^ List Of Apollo Minor Planets
  3. ^ a b c d e f g h i "JPL Small-Body Database Browser: (2011 EO40)". Jet Propulsion Laboratory. Retrieved 31 March 2016.
  4. ^ "List Of The Potentially Hazardous Asteroids (PHAs)". Retrieved 27 June 2014.
  5. ^ NEODyS-2 on 2011 EO40 Retrieved 2013-07-31
  6. ^ a b Absolute-magnitude conversion table (H)
  7. ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (21 November 2013). "The Chelyabinsk superbolide: a fragment of asteroid 2011 EO40?". Monthly Notices of the Royal Astronomical Society: Letters. 436 (1): L15–L19. arXiv:1307.7918. Bibcode:2013MNRAS.436L..15D. doi:10.1093/mnrasl/slt103.
  8. ^ a b c de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (1 September 2014). "Reconstructing the Chelyabinsk event: pre-impact orbital evolution". Monthly Notices of the Royal Astronomical Society: Letters. 443 (1): L39–L43. arXiv:1405.7202. Bibcode:2014MNRAS.443L..39D. doi:10.1093/mnrasl/slu078.
  9. ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl; Aarseth, S. J. (10 October 2015). "Chasing the Chelyabinsk asteroid N-body style". The Astrophysical Journal. 812 (1): 26 (22 pp). arXiv:1508.05907. Bibcode:2015ApJ...812...26D. doi:10.1088/0004-637X/812/1/26.
  10. ^ a b MPC data on 2011 EO40
  11. ^ "Observations of small Solar-System bodies". hohmanntransfer. 11 March 2011. Retrieved 6 August 2013. (2.7e-07 = 1 in 3,704,000 chance)
  12. ^ "2011EO40 Ephemerides for 23 August 2025 through 30 September 2025". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 4 July 2014.

External linksEdit