Asteroid 2021 AA flew past Earth at 0.6 LD

Written byTeo Blašković Updated on
asteroid-2021-aa

A newly-discovered asteroid designated 2021 AA flew past Earth at a distance of 0.62 LD / 0.00159 AU (237 860 km / 147 800 miles) from the center of our planet at 13:16 UTC on January 1, 2021.

This is the first known asteroid to flyby Earth within 1 lunar distance since the start of the year.

In 2020, we had 107 such flybys, up from 77 in 2019, 76 in 2018, 55 in 2017, and 53 in 2016.

Asteroid 2021 AA was first observed at Mt. Lemmon Survey, Arizona on January 2, one day after it made its close approach to Earth.

It belongs to the Apollo group of asteroids and has an estimated diameter between 11 and 24 m (36 – 79 feet).

 Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Close-Approach Data

<1LD asteroids in 2021

Asteroid flybys within 1 lunar distance in 2021 (total 1, valid 13:21 UTC, January 3, 2021):

NEODATE / TIME UTCDISTANCE LD | AU Diameter (m)
2021 AAJanuary 1 @ 13:16 ± 00:010.62 | 0.0015911 – 24

<1LD asteroids in 2020

Asteroid flybys within 1 lunar distance in 2020 (total 107, valid 13:21 UTC, January 3, 2021):

NEODATE / TIME UTCDISTANCE LD | AU Diameter (m)
2020 YS4December 28 @ 22:27 ± < 00:010.25 | 0.000647.7 – 17
2020 YJ2December 21 @ 04:57 ± < 00:010.89 | 0.002299.4 – 21
2020 YS2December 20 @ 06:04 ± 00:030.23 | 0.000581.7 – 3.8
2020 YR2December 19 @ 19:36 ± 00:050.45 | 0.001155.4 – 12
2020 XX3December 18 @ 06:47 ± 00:560.15 | 0.000385.1 – 11
2020 XF4December 16 @ 11:17 ± 00:020.89 | 0.002298.8 – 20
2020 XG2December 7 @ 19:15 ± 00:020.13 | 0.000337 – 16
2020 XK1December 7 @ 16:15 ± 00:020.05 | 0.000142 – 4.4
2020 VZ6December 3 @ 10:06 ± < 00:010.94 | 0.0023325 – 57
2020 XFDecember 3 @ 09:00 ± < 00:010.23 | 0.0005912 – 28
2020 XE1December 3 @ 08:23 ± 00:030.85 | 0.0021812 – 27
2020 XEDecember 1 @ 12:24 ± 00:100.77 | 0.0019916 – 35
2020 SO***December 1 @ 08:47 ± < 00:010.13 | 0.000344.9 – 11
2020 XCNovember 30 @ 10:16 ± 00:020.32 | 0.000814.2 – 9.4
2020 WF5November 26 @ 08:16 ± < 00:010.52 | 0.001357.5 – 17
 2020 WG5November 26 @ 02:36 ± < 00:010.94 | 0.002427.7 – 17
2020 WY4November 24 @ 03:19 ± 00:040.29 | 0.000754.4 – 9.9
2020 VH5November 13 @ 19:46 ± < 00:010.66 | 0.001693.9 – 8.6
2020 VT4November 13 @ 17:20 ± 00:030.02 | 0.0000451*4.9 – 11
2020 VP1November 11 @ 06:59 ± 00:090.48 | 0.001237.9 – 17
2020 VR1November 9 @ 17:51 ± < 00:010.99 | 0.002544.4 – 9.8
2020 VO1November 6 @ 23:48 ± 00:020.45 | 0.001166.7 – 15
2020 VWNovember 2 @ 09:05 ± 00:420.58 | 0.001485.4 – 12
2020 UF3October 22 @ 15:53 ± < 00:010.11 | 0.000295.7 – 13
2020 UO3October 22 @ 15:53 ± < 00:010.91 | 0.002346.2 – 14
2020 UYOctober 21 @ 04:24 ± 00:010.91 | 0.002354.3 – 9.6
2020 UAOctober 21 @ 02:00 ± < 00:010.12 | 0.000305.6 – 12
2020 TF6October 19 @ 19:24 ± < 00:010.40 | 0.001038.1 – 18
2020 UXOctober 19 @ 06:56 ± 00:180.49 | 0.001261.6 – 3.6
2020 TE6October 18 @ 19:19 ± < 00:010.60 | 0.001548.4 – 19
2020 TG6October 17 @ 18:03 ± < 00:010.36 | 0.000934.1 – 9.2
2020 UEOctober 15 @ 08:55 ± < 00:010.71 | 0.0018221 – 46
2020 TK7October 14 @ 16:00 ± < 00:010.20 | 0.000503.2 – 7.2
2020 TD7October 14 @ 16:00 ± 00:010.88 | 0.0022711 – 26
2020 TS1October 12 @ 10:57 ± < 00:010.66 | 0.001704 – 9
2020 TE5October 9 @ 18:18 ± 00:050.15 | 0.000384.2 – 9.3
2020 TAOctober 1 @ 11:06 ± 00:020.57 | 0.0014721 – 47
2020 SQ4September 26 @ 18:05 ± < 00:010.92 | 0.002364.5 – 10
2020 SN5September 24 @ 12:47 ± < 00:010.53 | 0.001356.1 -14
2020 SWSeptember 24 @ 11:13 ± < 00:010.07 | 0.000194.3 – 9.7
2020 SG6September 23 @ 12:45  ± < 00:040.58 | 0.001493.7 – 8.3
2020 SZ2September 19 @ 04:16 ± < 00:010.95 | 0.002453.5 – 7.9
2020 RZ6September 17 @ 18:23 ± < 00:010.88 | 0.0022712 – 27
2020 RD4September 14 @ 20:33 ± < 00:010.28 | 0.000712.9 – 6.5
2020 RF3September 14 @ 06:49 ± 00:010.24 | 0.000635.3 – 12
2020 SPSeptember 13 @ 00:57 ± 00:020.86 | 0.002229.9 – 22
2020 RG10September 10 @ 11:33 ± 00:020.35 | 0.000914.3 – 9.7
2020 RE5September 9 @ 16:50 ± 00:030.64 | 0.001644.1 – 9.2
2011 ES4September 1 @ 16:12 ± < 00:010.32 | 0.0008122 – 49
2020 QR5August 23 @ 04:20  ± < 00:010.83 | 0.002149.1 – 20
2020 QQ4August 22 @ 23:18 ± < 00:010.80 | 0.002064.6 – 10
2020 QN4August 21 @ 04:23 ± < 00:010.71 | 0.001825 – 11
2020 QY2August 20 @ 23:50 ± < 00:010.17 | 0.000441.6 – 3.6
2020 PY2August 20 @ 21:29 ± < 00:010.91 | 0.0023412 – 27
2020 QF2August 18 @ 01:41 ± < 00:010.55 | 0.001407.1 – 16
2020 QGAugust 16 @ 04:09 ± < 00:010.02 | 0.0000623**2.9 – 6.4
2020 PW2August 14 @ 04:25 ± < 00:010.73 | 0.001874.9 – 11
2020 QJ5August 12 @ 14:59 ± < 00:010.77 | 0.0019712 – 26
2020 PX5August 11 @ 08:45 ± < 00:010.59 | 0.001533.2 – 7.2
2020 PAAugust 1 @ 01:56 ± < 00:010.15 | 0.000394.6 – 10
2020 OY4July 28 @ 05:32  ± < 00:010.11 | 0.000282.3 – 5.2
2020 NBJuly 5 @ 21:21 ± < 00:010.46 | 0.0011915 – 33
2020 ML2June 13 @ 04:45 ± < 00:010.93 | 0.002386.7 – 15
2020 LDJune 5 @ 08:25 ± 00:05 0.80 | 0.0020589 – 200
2020 KC5May 29 @ 20:46 ± < 00:010.97 | 0.002489.1 – 20
2020 KJ4May 28 @ 13:21 ± < 00:010.37 | ​0.000962.8 – 6.2
2020 KF5May 28 @ 12:47 ± < 00:080.64 | 0.001653.5 – 7.8
2020 JNMay 5 @ 03:22 ± < 00:010.65 | ​0.001679 – 20
2020 JJMay 4 @ 12:05 ± < 00:010.03 | 0.00008962.7 – 6
2020 JAMay 3 @ 20:01 ± < 00:010.62 | 0.001609.6 – 22
2020 JGApril 30 @ 19:38 ± < 00:020.56 | 0.0014318 – 41
2020 HS7April 28 @ 18:51 ± < 00:010.11 | 0.000294 – 8.9
2020 HP6April 27 @ 14:40 ± < 00:010.33 | 0.000846.7 – 15
2020 HT8April 26 @ 13:33 ± 00:010.38 | 0.000995.8 – 13
2020 HX3April 24 @ 19:38 ± < 00:010.66 | 0.0016911 – 24
2020 HU7April 22 @ 20:19 ± < 00:010.34 | 0.000873.1 – 7
2020 HF5April 22 @ 16:41 ± < 00:010.38 | 0.00098 12 – 27
2020 HM6April 22 @ 05:51 ± 00:050.42 | 0.0010913 – 28
2020 GH2April 15 @ 12:45 ± 00:500.93 | 0.0024013 – 30
2020 HOApril 15 @ 10:06 ± 00:01 0.75 | 0.001934.6 – 10
2020 GY1April 5 @ 07:37 ± < 00:010.21 | 0.0005413 – 28
2020 GHApril 3 @ 22:04 ± < 00:010.33 | 0.000844.1 – 9.2
2020 GO1April 1 @ 19:09 ± < 00:010.18 | 0.000467.9 – 18
2020 FB7March 31 @ 16:17 ± < 00:010.20 | 0.0005216 -36
2020 FJ4March 25 @ 13:42 ± < 00:010.67 | 0.001723.4 – 7.6
2020 FL2March 22 @ 20:32 ± < 00:010.38 | 0.0009915 – 33
2020 FG4March 19 @ 00:51 ± 00:010.49 | 0.0012610 – 23
2020 FDMarch 18 @ 04:05 ± < 00:010.67 | 0.001717.8 – 17
2020 FD2March 18 @ 20:17 ± 00:310.85 | 0.0021920 – 44
2020 DR4February 24 @ 20:30 ± 00:030.24 | 0.000623 – 6.8
2020 DWFebruary 18 @ 17:02 ± < 00:010.63 | 0.001612.3 – 5.1
2020 DA1February 18 @ 10:32 ± < 00:010.50 | 0.001293.1 – 6.8
2020 CQ2February 14 @ 02:19 ± < 00:010.39 | 0.000995 – 11
2020 CD3February 13 @ 16:20 ± < 00:010.12 | 0.000311.2 – 2.7
2020 DUFebruary 13 @ 13:22 ± 00:060.85 | 0.002174.9 – 11
2020 CQ1February 4 @ 11:16 ± 00:020.17 | 0.000434.6 – 10
2020 BT14February 3 @ 08:19 ± < 00:010.49 | 0.00126​7.9 – 18
2020 CAFebruary 2 @ 15:49 ± 00:020.57 | 0.00147​3.2 – 7.2
2020 CWFebruary 1 @ 12:50 ± < 00:01 0.04 | 0.000110.83 – 1.9
2020 CJJanuary 31 @ 19:03 ± < 00:01 0.92 | 0.0023611 – 24
2020 CZJanuary 31 @ 03:51 ± 00:480.82 | 0.002103.7 – 8.2
2020 BZ13January 29 @ 01:18 ± < 00:010.28 | 0.000712.9 – 6.5
2020 BA15January 28 @ 18:03 ± 00:020.98 | ​0.002518.9 – 20
2020 BA13January 27 @ 16:56 ± < 00:01 0.51 | ​0.001324.7 – 11
2020 BH6January 25 @ 05:11 ± < 00:010.18 | ​0.000475.2 – 12
2020 BB5January 22 @ 00:20 ± 00:200.69 | 0.001773.3 – 7.4
2020 BK3January 20 @ 20:51 ± 00:050.78 | 0.0020011 – 25
2020 AP1January 2 @ 15:33  ± 00:020.85 | 0.002183.2 – 7.2

*Currently closest asteroid flyby on record

**2nd closest asteroid flyby on record

***Turned out to be a rocket booster (source)

<1LD asteroids in 2019

Asteroids detected within 1 lunar distance in 2019 (total 77):

NEODATE / TIME UTCDISTANCE LD | AU Diameter (m)
2019 YV4December 25 @ 21:41 ± 11:010.98 | 0.002519.3 – 21
2019 YU2December 23 @ 19:28 ± < 00:010.26 | 0.000668.9 – 20
2019 YSDecember 18 @ 15:12 ± < 00:010.17 | 0.000441.3 – 3
2019 YBDecember 18 @ 00:12 ± 00:03 0.44 | 0.001133.1 – 7
2019 WJ4November 30 @ 20:05 ± < 00:010.85 | 0.002195.5 – 12
2019 WG2November 23 @ 08:44 ± < 00:010.47 | 0.0012126 – 59
2019 WV1November 19 @ 23:45 ± 03:130.72 | ​0.001866.3 – 14
2019 WHNovember 19 @ 08:01 ± < 00:010.22 | ​0.0005716 – 36
2019 VF5November 9 @ 23:16 ± < 00:010.49 | 0.001278.3 – 19
2019 VB5November 9 @ 17:29 ± < 00:010.38 | 0.000971.2 – 2.7
2019 VS4November 6 @ 16:28 ± < 00:010.36 | 0.000939.3 – 21
2019 VRNovember 4 @ 10:35 ± < 00:010.35 | 0.000916.5 – 14
2019 VDNovember 4 @ 09:55 ± 00:010.45 | 0.001168.7 – 19
2019 VANovember 2 @ 17:41 ± 00:12 0.28 | 0.000725.6 – 12
2019 UG11November 1 @ 20:42 ± 00:020.55 | 0.0014013 – 29
2019 UN13October 31 @ 14:45 ± < 00:010.03 | 8.43e-51 – 2.2
2019 UB8October 29 @ 06:30 ± 00:030.50 | 0.001274 – 8.9
2019 UD10October 27 @ 10:08 ± 00:020.44 | 0.001126.3 – 14
2019 UX12October 26 @ 03:08 ± 00:040.99 | 0.002554.9 – 11
2019 UO8October 25 @ 13:30 ± 00:010.41 | 0.001053.1 – 6.9
2019 UN8October 23 @ 16:41 ± 00:170.93 | 0.00235 3.1 – 6.9
2019 UL3October 19 @ 22:23 ± 00:080.77 | 0.001996 – 13
2019 UGOctober 18 @ 09:23 ± < 00:010.84 | 0.002156.8 – 15
2019 UU1October 18 @ 06:23 ± < 00:010.59 | 0.001502.1 – 5.1
2019 TN5October 5 @ 22:38 ± < 00:010.32 | 0.000835.5 – 12
2019 SP3October 3 @ 06:36 ± 00:340.97 | 0.0024813 – 30
2019 SM8October 1 @ 13:56 ± < 00:01 0.41 | ​0.001063.8 – 8.6
2019 TDSeptember 29 @ 18:50 ± 00:130.34 | ​0.000874.1 – 9.1
2019 TESeptember 28 @ 20:31 ± 01:310.93 | 0.002386.8 – 15
2019 SX8September 28 @ 07:49 ± 00:380.99 | 0.002554.6 – 10
2019 SS3September 22 @ 22:48 ± 00:210.73 | 0.0018815 – 34
2019 SS2September 21 @ 07:12 ± 00:020.30 | ​0.000772 – 4.4
2019 SD1September 21 @ 06:46 ± < 00:01 0.73 | 0.001875.5 – 12
2019 SU2September 21 @ 02:48 ± 00:050.19 | 0.000482.7 – 6.1
2019 SJSeptember 16 @ 18:55 ± 00:030.64 | 0.001638.6 – 19
2019 RC1September 7 @ 10:48 ± 00:040.48 | ​0.001234.5 – 10
2019 RP1September 5 @ 22:04 ± < 00:01 0.10 | ​0.000257.4 – 17
2019 RQSeptember 2 @ 16:45 ± < 00:01 0.29 | ​0.000742.1 – 4.6
2019 QQ3August 26 @ 15:14 ± 00:010.25 | 0.000643.7 – 8.2
2019 QR8August 26 @ 08:51 ± 01:080.80 | ​0.002076.6 – 15
2019 QDAugust 22 @ 01:28 ± < 00:08 0.78 | 0.002004.7 – 11
2019 QH2August 20 @ 18:12 ± 00:080.13 | 0.000332.2 – 5
2019 QB1August 20 @ 11:55 ± 00:080.32 | 0.000829.3 – 21
2019 ON3July 29 @ 01:19 ±  00:140.56 | 0.001437.4 – 16
2019 OD3July 28 @ 02:56 ± < 00:010.49 | 0.0012611 – 25
2019 OKJuly 25 @ 01:22 ± < 00:040.19 | ​0.0004857 – 130
2019 ODJuly 24 @ 13:31 ± 00:040.93 | ​0.0023954 – 120
2019 NN3July 10 @ 16:29 ± < 00:010.83 | 0.0021435 – 77
2019 NF7July 9 @ 12:07 ± < 00:01 0.98 | 0.002536.4 – 14
2019 MB4July 9 @ 07:20 ± < 00:010.82 | 0.0021117 – 38
2019 NK1July 2 @ 09:48 ± 00:050.69 | 0.001772.9 – 6.5
2019 LW4June 8 @ 17:04 ± < 00:010.65 | ​​0.001669.3 – 21
2019 LY4June 6 @ 01:30 ± < 00:010.22 | ​​0.000567.3 – 16
2019 KTMay 28 @ 03:48 ± < 00:010.85 | ​0.0021713 – 29
2019 JH2May 16 @ 00:06 ± < 00:010.19 | ​0.000483.1 – 7
2019 JY2May 5 @ 17:12 ± < 00:010.38 | 0.000983.3 – 7.3
2019 JX1May 2 @ 12:39 ± 00:020.47 | 0.001203.8 – 8.6
2019 JKApril 30 @ 08:12 UTC ± 00:010.69 | 0.001787.1 – 16
2019 HEApril 20 @ 21:12 ± < 00:010.58 | 0.0014913 – 30
2019 GC6April 18 @ 06:39 ± 00:290.57 | 0.0014713 – 28
2019 GN20April 12 @ 07:06 ± < 00:010.98 | 0.0025314 – 31
2019 FP21March 31 @ 19:00  ±  07:460.93 | 0.002383 – 6.6
2019 FV1March 31 @ 05:27 ± < 00:010.87 | 0.002234.6 – 10
2019 FC1March 28 @ 05:46 ± < 00:010.27 | 0.0006920 – 45
2019 FQMarch 23 @ 18:17 UTC ± < 00:010.86 | 0.0022010 – 23
2019 EA2March 22 @ 01:53 UTC ± 00:020.80 | 0.0020518 – 40
2019 FAMarch 16 @ 01:14 UTC ± < 00:010.60 | 0.001544.9 – 11
2019 EN2March 13 @ 23:38 UTC ± < 00:010.86 | 0.002218 – 18
2019 EH1March 1 @ 17:38 UTC ± < 00:010.06 | 0.000162.5 – 5.7
2019 DFFebruary 26 @ 21:21 UTC  ± 00:090.47 | 0.001203.0 – 6.7
2019 DG2Febraury 26 @ 07:39 UTC ± 07:390.61 | 0.001585.4 – 12
2019 CN5February 11 @ 07:23 UTC ± 00:030.31 | 0.000797.3 – 16
2019 BZ3January 27 @ 23:29 ± < 00:010.13 | 0.00032 4.8 – 11
2019 BV1January 24 @ 20:53 ± < 00:010.35 | 0.00090 4.8 – 11
2019 BOJanuary 16 @ 01:13 ± 00:020.18 | 0.00046 6.3 – 14
2019 AE9January 12 @ 11:09 ± < 00:010.26 | 0.00067 9.9 – 22
2019 AS5January 8 @ 00:37 ± < 00:010.04 | 0.00010 0.92 – 2.1

 

<1LD asteroid charts

Asteroids within 1 LD 2018 – 2021.

Reference

Asteroid 2021 AA at Minor Planet Center, CNEOS

Featured image credit: MPC

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Asteroid 2024 JT3 to fly past Earth at just 0.07 LD on May 9

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Asteroid 2024 GX3 flew past Earth at 0.18 LD

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Asteroid 2024 LH1 flew past Earth at 0.02 LD on June 6

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Asteroid 2024 JN16 to fly past Earth at a very close distance of 0.06 LD on May 14

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Asteroid 2024 JT3 to fly past Earth at just 0.07 LD on May 9

Wednesday, May 8, 2024

Near-Earth asteroids 2024 JR1 and 2024 JD close approach live views

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Asteroid 2024 HA flew past Earth at just 0.04 LD – the closest flyby of the year and 20th closest on record

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Asteroid 2024 GX3 flew past Earth at 0.18 LD

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I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.

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