2022 AE1

2022 AE₁ is a Tunguska event-sized asteroid, classified as a near-Earth object of the Apollo group, approximately 70 meters (230 feet) in diameter.^[5] It was discovered by the Mount Lemmon Survey on 6 January 2022, when it was 0.09 AU (13 million km) from Earth.^[1] On 9 January 2022 with an observation arc of 3 days, it was rated with a Torino scale of 1 for a virtual impactor on 4 July 2023 16:28 UTC.^[3][a] Nominal approach is expected to occur 1 July 2023 01:13 ± 1 day.^[2][b] With a Palermo scale rating of as high as –0.66 at the European Space Agency on 11 January 2022,^[6] the odds of impact peaked at about 4.6^[c] times less than the background hazard level.^[d] NEODyS was the first risk-page to drop to Torino scale 0 on 12 January 2022^[7] followed by ESA on 13 January 2022,^[6] but by January 14 both returned to Torino scale 1. On 14 January 2022 the waxing gibbous moon was as little as 3 degrees from the asteroid delaying observations of the asteroid from January 12–19.^[8] On 20 January 2022 with a 16-day observation arc, using JPL #11 the Sentry Risk Table dropped the asteroid to Torino scale 0 and then later that day JPL #12 resulted in it being removed from the risk table.^[9][10]

2022 AE1 nominal approach for 4 July 2023 virtual impactor^[a]

Observation arc (in days)	JPL Horizons nominal geocentric distance (AU)	uncertainty region (3-sigma)	Impact probability (1 in)	Torino scale
2.9	0.024 AU (3.6 million km)[11]	± 38 million km[11]	2900	1
5.9	0.043 AU (6.4 million km)[12]	± 31 million km[12]	1800	1
7.1	0.043 AU (6.4 million km)[13]	± 22 million km[13]	1500	1
7.9	0.066 AU (9.9 million km)[14]	± 20 million km[14]	2800	1
8.1	0.039 AU (5.8 million km)[15]	± 12 million km[15]	1700	1
16.1	0.053 AU (7.9 million km)[16]	± 7 million km[16][b]	71000	0
16.1 (JPL #12)	0.059 AU (8.8 million km)[17]	± 5 million km[17]	0[3]	0[3]
20	0.072 AU (10.8 million km)[18]	± 4 million km[18]	0	0

2022 AE₁
2023 Earth/Moon approach
JPL #15 (20-day arc)
Uncertainty: ± 1 day and ± 3.5 million km

Date & Time	Approach to	Nominal distance
2023-Jul-01 01:13 ± 1 day	Earth	9246404 km[2]
2023-Jul-01 03:44	Moon	9463958 km[19]

2022 AE₁

Discovery[1]
Discovered by	Mount Lemmon Survey
Discovery site	Mount Lemmon Obs.
Discovery date	6 January 2022
Designations
MPC designation	2022 AE1
Minor planet category	NEO Apollo
Orbital characteristics[2]
Epoch 2022-Jan-21 (JD 2459600.5)
Uncertainty parameter 7
Observation arc	20 days
Aphelion	2.27 AU (Q)
Perihelion	0.667 AU (q)
Semi-major axis	1.47 AU (a)
Eccentricity	0.547 (e)
Orbital period (sidereal)	1.78 years
Mean anomaly	39° (M)
Inclination	6.3° (i)
Longitude of ascending node	102.2° (Ω)
Time of perihelion	10 November 2021
Argument of perihelion	268.3° (ω)
Earth MOID	0.00007 AU (10 thousand km)
Jupiter MOID	3.2 AU (480 million km)
Physical characteristics
Mean diameter	~70 m (200 ft)[3] 54–120 meters
Absolute magnitude (H)	23.49[4]

It came to perihelion (closest approach to the Sun) on 10 November 2021, and then approached Earth from the direction of the Sun making closest Earth approach on 31 December 2021 at distance of about 10 million km.^[2]

See also

• 2021 TP21
• 2022 BX1

Notes

1. Earth traveling at 30 km/s and with a diameter of 12,800 km, only blocks the path of the asteroid for about 8 minutes (30 km/s * 60 sec * 8 min).
2. The JPL Small-Body Database close approach table lists a linearized uncertainty. Sentry computations explore alternate orbit solutions along the line of variations and account for orbit propagation nonlinearities.
3. 10^0.66 = 4.57. JPL's Sentry Risk Table, ESA's Risk List and NEODyS will all list slightly different odds of impact and Palermo scale values.
4. "Background risk" is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact.