2021 BA is an asteroid in the Apollo orbit class. Its orbit takes it from 0.77 AU to 1.24 AU from the Sun; one orbit takes 367.7 days. Orbit from the JPL solution of 13 January 2023.
Where is it now
- Distance from Sun
- 1.225 AU
- True anomaly
- 194.01°
- Distance from Earth
- 0.361 AU
- As of
- 3 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
- 05h 42m 01s
- Declination
- -19° 11′ 08″
- Constellation
- Lepus
- Distance from Earth
- 0.36 AU
- Elongation from the Sun
- 122.71° — well clear of the Sun
Favours the southern hemisphere; low or below the horizon from far north.
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
- 1.004 AU
- Eccentricity
- 0.2305
- Inclination
- 12.46°
- Orbital period
- 367.7 days
- Perihelion
- 0.773 AU
- Aphelion
- 1.236 AU
- Longitude of ascending node
- 116.93°
- Argument of periapsis
- 98.58°
- Epoch · J2000
- 2461200.5
- Orbit class · APO
- Apollo
- Earth MOID · 0.3 LD
- 0.0007 AU
- Tisserand (Jupiter)
- 6.015
Orbit quality
Orbit very well determined (uncertainty code 1).
- Observations used
- 61
- Data arc
- 727 days
- First observed
- 16 January 2021
- Last observed
- 13 January 2023
- Residual RMS
- 0.37 ″
- Solution · Otto Matic
- 13 January 2023
Visual & observation
- Absolute magnitude (H)
- 26
Discovery & classification
Close approaches 142 on record
Top-down view of the ecliptic, Earth at the centre, for the 2027-01-06 18:45 UTC close approach of 2021 BA. Catalogue miss distance 82.0 LD · 3.15 × 10⁷ km. The curve is the geocentric path from 2027-01-03 to 2027-01-09, 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 |
|---|---|---|---|---|
| 2027-01-06 18:45:00 | Earth | 0.2107 AU | 82.0 LD | 6.8 km/s |
| 2027-12-26 22:55:00 | Earth | 0.2446 AU | 95.2 LD | 6.9 km/s |
| 2028-03-07 21:31:00 | Earth | 0.258 AU | 100.4 LD | 6.6 km/s |
| 2028-12-15 16:20:00 | Earth | 0.2728 AU | 106.2 LD | 7 km/s |
| 2029-03-24 04:26:00 | Earth | 0.279 AU | 108.6 LD | 7.1 km/s |
| 2029-12-06 04:23:00 | Earth | 0.2957 AU | 115.1 LD | 7 km/s |
| 2030-04-05 14:42:00 | Earth | 0.2919 AU | 113.6 LD | 7.5 km/s |
| 2030-11-27 03:12:00 | Earth | 0.3136 AU | 122.1 LD | 7 km/s |
| 2031-04-16 15:26:00 | Earth | 0.2987 AU | 116.2 LD | 7.8 km/s |
| 2031-11-18 06:57:00 | Earth | 0.3269 AU | 127.2 LD | 6.9 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