| Minorplanet: | yes |
| Background: |
|
| Discoverer: | Catalina Sky Survey Richard A. Kowalski |
| Discovered: | 4 February 2011 |
| Epoch: | 13 January 2016 (JD 2457400.5) |
| Uncertainty: | 5 |
| Observation Arc: | 12.4 hours (35 observations used) |
| Aphelion: | 1.0087abbr=onNaNabbr=on (Q) |
| Perihelion: | 0.66454AU (q) |
| Semimajor: | 0.83661AU (a) |
| Eccentricity: | 0.20567 (e) |
| Period: | 0.77 yr (279.5 d) |
| Inclination: | 5.2445° (i) |
| Asc Node: | 315.23° (Ω) |
| Mean Anomaly: | 18.607° (M) |
| Arg Peri: | 335.40° (ω) |
| Dimensions: | ~2m (07feet) |
| Magnitude: | 14.2 (2011 peak) |
| Abs Magnitude: | 32.1 |
| Mean Motion: | 1.2880°/day (n) |
| Moid: | 0.000166307AU |
| Jupiter Moid: | 4.09715AU |
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 (5480km (3,410miles)) 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 80cm (30inches) and 2.6m (08.5feet) wide. The meteoroid was removed from the Sentry Risk Table on 5 February 2011.
| 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.