2011 EO40

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

Discovery, orbit and physical properties

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

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. 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. 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. 2011 EO₄₀ has an absolute magnitude of 21.5, which gives a characteristic diameter of about 200 metres (660 ft).

Relationship to the Chelyabinsk superbolide

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. It has relatively frequent close encounters with Venus, the Earth–Moon system, and Mars. It had a close encounter with Earth on 28 January 2011 at 0.0953 AU (14,260,000 km; 8,860,000 mi), and it will have a nominal Earth approach on 23 September 2025 at about 0.06 AU (9,000,000 km; 5,600,000 mi). 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.

Visibility

2011 EO₄₀ had opposition windows on 7 June 2016 at magnitude 24.5, and 28 May 2018 at magnitude 24.6 but was not observed during either opposition. The asteroid was recovered on 15 August 2025 by Pan-STARRS. The best observation window was on 2–23 September 2025. Depending on the Earth approach distance (0.04–0.12 AU), it should have been brighter than magnitude 19.

See also

• Carbonaceous chondrite
• Meteorite

Notes

References

External links

• 2011 EO₄₀ data at MPC
• MPEC 2011-E59 : 2011 EO40 (Discovery MPEC)
• Russian meteor may have gangmates in tow, Nature, short article
• Has the Chelyabinsk Meteor Parent Asteroid Been Found?, Bad Astronomy blog entry
• 2011 EO40 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• 2011 EO40 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• 2011 EO40 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters