Article · Wikipedia archive · Last revised Jul 7, 2026

2011 CQ1

2011 CQ1 is a meteoroid discovered on 4 February 2011 by Richard A. Kowalski, at the Catalina Sky Survey. On the same day the meteoroid passed within 0.85 Earth radii (5,480 kilometers (3,410 mi) of Earth's surface, and was perturbed from the Apollo class to the Aten class of near-Earth objects. With a relative velocity of only 9.7 km/s, had the asteroid passed less than 0.5 Earth radii from Earth's surface, it would have fallen as a brilliant fireball. The meteoroid is between 80 centimeters (31 in) and 2.6 meters (100 in) wide. The meteoroid was removed from the Sentry Risk Table on 5 February 2011.

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2011 CQ1
Discovery1
Discovered byCatalina Sky Survey
Richard A. Kowalski
Discovery date4 February 2011
Designations
Orbital characteristics2
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 5
Observation arc12.4 hours3
(35 observations used)
Aphelion1.0087 AU (150.90 Gm) (Q)
Perihelion0.66454 AU (99.414 Gm) (q)
0.83661 AU (125.155 Gm) (a)
Eccentricity0.20567 (e)
0.77 yr (279.5 d)
18.607° (M)
1.2880°/day (n)
Inclination5.2445° (i)
315.23° (Ω)
335.40° (ω)
Earth MOID0.000166307 AU (24,879.2 km)
Jupiter MOID4.09715 AU (612.925 Gm)
Physical characteristics
Dimensions~2 meters (79 in)
14.2 (2011 peak)4
32.12

2011 CQ1 is a meteoroid discovered on 4 February 2011 by Richard A. Kowalski, at the Catalina Sky Survey.1 On the same day the meteoroid passed within 0.85 Earth radii (5,480 kilometers (3,410 mi) of Earth's surface, and was perturbed from the Apollo class to the Aten class of near-Earth objects.5 With a relative velocity of only 9.7 km/s,2 had the asteroid passed less than 0.5 Earth radii from Earth's surface, it would have fallen as a brilliant fireball. The meteoroid is between 80 centimeters (31 in) and 2.6 meters (100 in) wide.5 The meteoroid was removed from the Sentry Risk Table on 5 February 2011.6

Parameter Epoch aphelion
(Q) 		perihelion
(q) 		Semi-major
axis
(a) 		eccentricity
(e) 		Period
(p) 		inclination
(i) 		Longitude
ascending
node
(Ω) 		Mean
anomaly
(M) 		Argument
of
perihelion
(ω)
Units AU (days) (°)
Pre-flyby 2011-Jan-26 1.347 0.9096 1.128 0.1940 437.9 1.073° 135.4° 310.9° 58.59°
Post-flyby 2011-Feb-08 1.009 0.6624 0.8360 0.2076 279.2 5.296° 315.4° 220.6° 335.1°

It was not until 2020 QG on 16 August 2020 that a non-impacting closer approach to Earth was observed.

Animation of 2011 CQ1's orbit - 2011 flyby
Around the Sun
Around the Earth
   Sun ·   2011 CQ1 ·   Earth
See also

See also

Closest non-impacting asteroids to Earth, except Earth-grazing fireballs
(using JPL SBDB numbers and Earth radius of 6,378 km)
Asteroid Date Distance from
surface of Earth 		Uncertainty in
approach distance 		Observation arc Reference
2025 UC11 2025-10-30 12:11 237 km ±11 km 1 day (41 obs) data
2020 VT4 2020-11-13 17:21 368 km ±11 km 5 days (34 obs) data
2020 QG 2020-08-16 04:09 2939 km ±11 km 2 days (35 obs) data
2021 UA1 2021-10-25 03:07 3049 km ±10 km 1 day (22 obs) data
2023 BU 2023-01-27 00:29 3589 km ±<1 km 10 days (231 obs) data
2011 CQ1 2011-02-04 19:39 5474 km ±5 km 1 day (35 obs) data
2019 UN13 2019-10-31 14:45 6235 km ±189 km 1 day (16 obs) data
2008 TS26 2008-10-09 03:30 6260 km ±970 km 1 day (19 obs) data
2004 FU162 2004-03-31 15:35 6535 km ±13000 km 1 day (4 obs) data
References

References

  1. "MPEC 2011-C12 : 2011 CQ1". IAU Minor Planet Center. 4 February 2011. Retrieved 27 February 2013. (K11C01Q)
  2. "JPL Close-Approach Data: (2011 CQ1)" (last observation: 2011-02-04; arc: 1 day). Archived from the original on 28 June 2021. Retrieved 31 March 2016.
  3. "2011 CQ1". Minor Planet Center. Retrieved 21 August 2020.
  4. "2011 CQ1 Ephemerides for 4 February 2011". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 28 February 2013.
  5. Don Yeomans & Paul Chodas (4 February 2011). "Very Small Asteroid Makes Close Earth Approach on 4 February 2011". News. NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 September 2011. Retrieved 18 September 2011.
  6. "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 June 2002. Retrieved 19 March 2012.
External links