| Time of discovery of asteroids which came closer to Earth than the moon in 2011 |
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Below is the list of asteroid close approaches to Earth in 2011.
| Time of discovery of asteroids which came closer to Earth than the moon in 2011 |
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Below is the list of asteroid close approaches to Earth in 2011.
A list of known near-Earth asteroid close approaches less than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2011. [note 1]
Rows highlighted red indicate objects which were not discovered until after closest approach
Rows highlighted yellow indicate objects discovered less than 24 hours before closest approach
Rows highlighted green indicate objects discovered more than one week before closest approach
Rows highlighted turquoise indicate objects discovered more than 7 weeks before closest approach
Rows highlighted blue indicate objects discovered more than one year before closest approach (i.e.
objects successfully cataloged on a previous orbit, rather than being detected during final approach)
This list does not include any of the objects that collided with earth in 2011, none of which were discovered in advance, but were recorded by sensors designed to detect detonation of nuclear devices.
| Date of closest approach | Date discovered | Object | Nominal geocentric distance (AU) [note 2] | Size (m) (approximate) [note 3] | (H) | Closer approach to Moon | Refs [1] [2] |
|---|---|---|---|---|---|---|---|
| 2011-01-11 | 2011-01-13 | 2011 AM37 | 0.00086 AU (129,000 km ; 80,000 mi ) | 6 | 29.7 [3] | data · 2011 AM37 | |
| 2011-01-17 | 2011-01-14 | 2011 AN52 | 0.00213 AU (319,000 km; 198,000 mi) | 11 | 28.6 [4] | Yes | data · 2011 AN52 |
| 2011-01-20 | 2011-01-24 | 2011 BY10 | 0.00238 AU (356,000 km; 221,000 mi) | 22 | 27.1 [5] | Yes | data · 2011 BY10 |
| 2011-01-25 | 2011-01-26 | 2011 BW11 | 0.00086 AU (129,000 km; 80,000 mi) | 13 | 28.3 [6] | data · 2011 BW11 | |
| 2011-01-31 | 2011-02-05 | 2011 CA4 | 0.00165 AU (247,000 km; 153,000 mi) | 22 | 27.1 [7] | data · 2011 CA4 | |
| 2011-02-04 | 2011-02-04 | 2011 CQ1 | 0.000079 AU (11,800 km; 7,300 mi) | 1 | 32.1 [8] | data · 2011 CQ1 | |
| 2011-02-06 | 2011-02-07 | 2011 CF22 | 0.00026 AU (39,000 km; 24,000 mi) | 3 | 30.9 [9] | data · 2011 CF22 | |
| 2011-02-09 | 2011-02-07 | 2011 CA7 | 0.00069 AU (103,000 km; 64,000 mi) | 5 | 30.3 [10] | data · 2011 CA7 | |
| 2011-02-23 | 2011-02-27 | 2011 DU9 | 0.00192 AU (287,000 km; 178,000 mi) | 27 | 26.7 [11] | data · 2011 DU9 | |
| 2011-03-03 | 2011-03-04 | 2011 EN11 | 0.00166 AU (248,000 km; 154,000 mi) | 15 | 27.9 [12] | data · 2011 EN11 | |
| 2011-03-07 | 2011-03-05 | 2011 EY11 | 0.000876 AU (131,000 km; 81,400 mi) | 11 | 28.5 [13] | data · 2011 EY11 | |
| 2011-03-08 | 2011-03-10 | 2011 EM40 | 0.00161 AU (241,000 km; 150,000 mi) | 14 | 28.0 [14] | data · 2011 EM40 | |
| 2011-04-06 | 2011-04-04 | 2011 GW9 | 0.00132 AU (197,000 km; 123,000 mi) | 14 | 28.1 [15] | data · 2011 GW9 | |
| 2011-04-06 | 2011-04-04 | 2011 GP28 | 0.00063 AU (94,000 km; 59,000 mi) | 7 | 29.4 [16] | data · 2011 GP28 | |
| 2011-05-05 | 2011-05-08 | 2011 JV10 | 0.00231 AU (346,000 km; 215,000 mi) | 6 | 29.7 [17] | Yes | data · 2011 JV10 |
| 2011-06-02 | 2009-01-16 | 2009 BD | 0.00231325 AU (346,057 km; 215,030 mi) | 14 | 28.1 [18] | data · 2009 BD | |
| 2011-06-27 | 2011-06-22 | 2011 MD | 0.00012467 AU (18,650 km; 11,589 mi) | 14 | 28.0 [19] | data · 2011 MD | |
| 2011-07-24 | 2011-08-06 | 2011 PU1 | 0.00224 AU (335,000 km; 208,000 mi) | 60 | 25.0 [20] | Yes | data · 2011 PU1 |
| 2011-07-28 | 2011-07-31 | 2011 OD18 | 0.00115 AU (172,000 km; 107,000 mi) | 30 | 26.5 [21] | data · 2011 OD18 | |
| 2011-09-27 | 2011-09-23 | 2011 SE58 | 0.00158 AU (236,000 km; 147,000 mi) | 16 | 27.8 [22] | data · 2011 SE58 | |
| 2011-09-28 | 2011-10-01 | 2011 TO | 0.00086 AU (129,000 km; 80,000 mi) | 30 | 26.3 [23] | data · 2011 TO | |
| 2011-09-30 | 2011-09-29 | 2011 SM173 | 0.00194 AU (290,000 km; 180,000 mi) | 16 | 27.8 [24] | data · 2011 SM173 | |
| 2011-10-12 | 2011-10-17 | 2011 UT | 0.0015 AU (220,000 km; 140,000 mi) | 37 | 26.0 [25] | Yes | data · 2011 UT |
| 2011-10-17 | 2009-10-15 | 2009 TM8 | 0.00219 AU (328,000 km; 204,000 mi) | 6–12 | 28.4 | Yes | data · 2009 TM8 |
| 2011-10-26 | 2011-10-27 | 2011 UL169 | 0.00177 AU (265,000 km; 165,000 mi) | 13 | 28.3 [26] | data · 2011 UL169 | |
| 2011-10-28 | 2011-10-30 | 2011 UX255 | 0.00092 AU (138,000 km; 86,000 mi) | 19 | 27.4 [27] | data · 2011 UX255 | |
| 2011-11-08 | 2005-12-28 | (308635) 2005 YU55 | 0.00217202 AU (324,930 km; 201,902 mi) | 360 | 21.9 [28] | Yes | data · 2005 YU55 |
| 2011-12-03 | 2011-12-08 | 2011 XC2 | 0.00232 AU (347,000 km; 216,000 mi) | 100 | 23.1 [29] | Yes | data · 2011 XC2 |
| 2011-12-28 | 2011-12-29 | 2011 YC40 | 0.00071 AU (106,000 km; 66,000 mi) | 6 | 29.7 [30] | data · 2011 YC40 | |
| 2011-12-29 | 2012-01-01 | 2012 AQ | 0.00179 AU (268,000 km; 166,000 mi) | 4 | 30.7 [31] | data · 2012 AQ | |
| 2011-12-30 | 2011-12-31 | 2011 YC63 | 0.00161 AU (241,000 km; 150,000 mi) | 9 | 29.0 [32] | data · 2011 YC63 |
This sub-section visualises the warning times of the close approaches listed in the above table, depending on the size of the asteroid. The sizes of the charts show the relative sizes of the asteroids to scale. For comparison, the approximate size of a person is also shown. This is based the absolute magnitude of each asteroid, an approximate measure of size based on brightness.
Abs Magnitude 30 and greater
(size of a person for comparison)
Abs Magnitude 29-30
Absolute Magnitude 28-29
Absolute Magnitude 27-28
Absolute Magnitude 26-27
Absolute Magnitude 25-26
Absolute Magnitude less than 25 (largest)
2010 AA15 is a sub-kilometer asteroid from the inner asteroid belt, that has a similar but different orbit than main-belt comet P/2010 A2. During January 2010, it had been observed for two weeks by the Mount Lemmon Survey, but has since become a lost asteroid. As of 2020 the object has not been recovered.
(415029) 2011 UL21, provisional designation 2011 UL21, is an Apollo class potentially hazardous asteroid discovered on October 17, 2011, by the Catalina Sky Survey project. The asteroid is estimated to have a diameter of 2.5 kilometres (1.6 mi). It was rated at Torino Scale 1 on October 27, 2011, with an observation arc of 9.6 days.
2014 JO25 is a near-Earth asteroid. It was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona - a project of NASA's NEO (Near Earth Object) Observations Program in collaboration with the University of Arizona.
2018 AH is a sub-kilometer asteroid, classified as near-Earth object of the Apollo group, approximately 100 m (300 ft) in diameter. It was first observed on 4 January 2018, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa and quickly followed-up by many other surveys, with precovery observations found from Pan-STARRS and PTF from the day previous.
2018 DV1 is a micro-asteroid, classified as a near-Earth object of the Aten group, approximately 6–12 meters (20–40 feet) in diameter. It was first observed on 26 February 2018, by astronomers of the Mount Lemmon Survey at Mount Lemmon Observatory, Arizona, five days prior to its sub-lunar close encounter with Earth at less than 0.3 lunar distance.
2018 GE3 is a sub-kilometer asteroid on a highly eccentric orbit, classified as a near-Earth object of the Apollo group, approximately 48–110 meters (160–360 feet) in diameter. It was first observed on 14 April 2018, by astronomers with the Catalina Sky Survey one day prior to its sub-lunar close encounter with Earth at 0.5 lunar distance. It is one of the largest known asteroids (possibly the largest) in observational history to ever pass that close to Earth (also see list).
2015 XY261 (also written 2015 XY261) is an Apollo near-Earth asteroid that is also a Mars crosser. It is roughly 10–22 meters in diameter and passed less than 1 lunar distance, 0.0025696 AU (384,410 km; 238,860 mi) from Earth on 15 December 2015.
2020 LD is an Apollo near-Earth asteroid roughly 140 meters in diameter. It was discovered on 7 June 2020 when the asteroid was about 0.03 AU from Earth and had a solar elongation of 154 degrees. The glare of the Sun had masked the approach of the asteroid since November 2019. The asteroid passed closest approach to Earth on 5 June 2020 at a distance of 0.002 AU. The close approach distance is now known with an accuracy of roughly ± 1000 km. This is the largest asteroid to pass closer than the Moon this year and possibly the largest since (308635) 2005 YU55 in November 2011. The asteroid makes close approaches to Mercury, Venus, Earth, and Mars. It will be brighter than apparent magnitude 24 until 18 July 2020.
