2021 AA1 is an asteroid in the Aten orbit class. Its orbit takes it from 0.83 AU to 1.13 AU from the Sun; one orbit takes 354.6 days. Orbit from the JPL solution of 15 April 2021.
Where is it now
- Distance from Sun
- 1.051 AU
- True anomaly
- 234.36°
- Distance from Earth
- 1.079 AU
- As of
- 2 November 2026
Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.
In the sky
- Right ascension
- 10h 46m 27s
- Declination
- +08° 19′ 41″
- Constellation
- Leo
- Distance from Earth
- 1.08 AU
- Elongation from the Sun
- 60.82° — well clear of the Sun
Visible from both hemispheres.
From your location
See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.
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Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.
Orbital elements
- Semi-major axis
- 0.98 AU
- Eccentricity
- 0.1527
- Inclination
- 17.26°
- Orbital period
- 354.6 days
- Perihelion
- 0.831 AU
- Aphelion
- 1.13 AU
- Longitude of ascending node
- 285.99°
- Argument of periapsis
- 303.58°
- Epoch · J2000
- 2461200.5
- Orbit class · ATE
- Aten
- Earth MOID · 21.8 LD
- 0.0559 AU
- Tisserand (Jupiter)
- 6.126
Orbit quality
Orbit poorly determined (uncertainty code 7).
- Observations used
- 32
- Data arc
- 8 days
- First observed
- 4 January 2021
- Last observed
- 12 January 2021
- Residual RMS
- 0.43 ″
- Solution · Otto Matic
- 15 April 2021
Visual & observation
- Absolute magnitude (H)
- 26.1
Discovery & classification
Close approaches 24 on record
Top-down view of the ecliptic, Earth at the centre, for the 2055-01-12 19:33 UTC close approach of 2021 AA1. Catalogue miss distance 35.1 LD · 1.35 × 10⁷ km. The curve is the geocentric path from 2055-01-09 to 2055-01-15, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. At closest approach the object is south of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate.
| When (UTC) | Body | Distance | Lunar distances | Relative speed |
|---|---|---|---|---|
| 2027-03-25 06:19:00 | Venus | 0.1435 AU | 55.8 LD | 12.2 km/s |
| 2055-01-12 19:33:00 | Earth | 0.0902 AU | 35.1 LD | 10.9 km/s |
| 2056-01-11 20:43:00 | Earth | 0.2501 AU | 97.4 LD | 14.7 km/s |
| 2057-01-06 19:10:00 | Earth | 0.4229 AU | 164.6 LD | 19.4 km/s |
| 2088-01-11 23:13:00 | Earth | 0.0566 AU | 22.0 LD | 9.9 km/s |
| 2089-01-12 04:58:00 | Earth | 0.1823 AU | 70.9 LD | 13 km/s |
| 2089-05-11 06:11:00 | Venus | 0.1415 AU | 55.1 LD | 12.6 km/s |
| 2090-01-09 01:28:00 | Earth | 0.3538 AU | 137.7 LD | 17.4 km/s |
| 2157-01-09 14:21:00 | Earth | 0.3694 AU | 143.8 LD | 17.9 km/s |
Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.
Sources
- visual properties: JPL SBDB (lookup)
- orbital elements: JPL SBDB