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.^[7][8][9]

2011 EO₄₀

Discovery[1]
Discovered by	Richard A. Kowalski (Mount Lemmon Survey)
Discovery date	10 March 2011
Designations
MPC designation	2011 EO40
Minor planet category	Apollo NEO PHA[2][3][4] Earth crosser
Orbital characteristics[3][5]
Epoch 9 August 2022 (JD 2459800.5)
Uncertainty parameter 6
Aphelion	2.5467 AU (380.98 Gm)
Perihelion	0.76039 AU (113.753 Gm)
Semi-major axis	1.65356 AU (247.369 Gm)
Eccentricity	0.54015
Orbital period (sidereal)	2.1264 yr (776.66 d)
Mean anomaly	169.9°
Mean motion	0° 27m 47.736s / day
Inclination	3.3591°
Longitude of ascending node	50.249°
Argument of perihelion	17.154°
Earth MOID	0.0482051 AU (7.21138 Gm)
Jupiter MOID	2.79322 AU (417.860 Gm)
Physical characteristics
Dimensions	150–330 m[a][6]
Absolute magnitude (H)	21.5[3]

Discovery, orbit and physical properties

2011 EO₄₀ was discovered by Richard A. Kowalski on 10 March 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 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.^[7][8][9] 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),^[3] 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).^[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]

Visibility

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

See also

• Carbonaceous chondrite
• Meteorite

Notes

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