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 1.65AU. 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 (660ft).

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 0.0953AU(14,260,000km; 8,860,000mi), and it will have a nominal Earth approach on 23 September 2025 at about 0.06AU (9,000,000km; 5,600,000mi). 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 7June 2016 at magnitude24.5, and 28May 2018 at magnitude24.6 but was not observed during either opposition. The asteroid was recovered on 15August 2025 by Pan-STARRS. The best observation window was on 2–23September 2025. Depending on the Earth approach distance (0.04–0.12AU), it should have been brighter than magnitude19.

See also

Notes

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

External links