2021 RO10 is an asteroid in the Apollo orbit class. Its orbit takes it from 0.91 AU to 1.15 AU from the Sun; one orbit takes 380.9 days. Orbit from the JPL solution of 27 September 2021.
Where is it now
- Distance from Sun
- 1.139 AU
- True anomaly
- 201.55°
- Distance from Earth
- 1.289 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
- 18h 45m 05s
- Declination
- -27° 13′ 50″
- Constellation
- Sagittarius
- Distance from Earth
- 1.29 AU
- Elongation from the Sun
- 58.06° — near the Sun — look low at dusk or dawn
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
- 1.028 AU
- Eccentricity
- 0.1181
- Inclination
- 13.73°
- Orbital period
- 380.9 days
- Perihelion
- 0.907 AU
- Aphelion
- 1.15 AU
- Longitude of ascending node
- 347.7°
- Argument of periapsis
- 137.47°
- Epoch · J2000
- 2461200.5
- Orbit class · APO
- Apollo
- Earth MOID · 22.5 LD
- 0.0579 AU
- Tisserand (Jupiter)
- 5.917
Orbit quality
Orbit poorly determined (uncertainty code 6).
- Observations used
- 23
- Data arc
- 16 days
- First observed
- 10 September 2021
- Last observed
- 26 September 2021
- Residual RMS
- 0.57 ″
- Solution · Otto Matic
- 27 September 2021
Visual & observation
- Absolute magnitude (H)
- 24.93
Discovery & classification
Close approaches 22 on record
Top-down view of the ecliptic, Earth at the centre, for the 2044-10-02 23:39 UTC close approach of 2021 RO10. Catalogue miss distance 109.3 LD · 4.2 × 10⁷ km. The curve is the geocentric path from 2044-09-29 to 2044-10-05, 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 north 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 |
|---|---|---|---|---|
| 2044-10-02 23:39:00 | Earth | 0.2808 AU | 109.3 LD | 11.8 km/s |
| 2045-09-21 20:39:00 | Earth | 0.1032 AU | 40.2 LD | 7.7 km/s |
| 2046-08-24 21:22:00 | Earth | 0.1843 AU | 71.7 LD | 7.3 km/s |
| 2047-03-17 21:48:00 | Earth | 0.0711 AU | 27.7 LD | 8.3 km/s |
| 2048-04-13 08:53:00 | Earth | 0.2984 AU | 116.1 LD | 13 km/s |
| 2068-10-03 07:17:00 | Earth | 0.344 AU | 133.9 LD | 13.5 km/s |
| 2069-09-26 19:48:00 | Earth | 0.1337 AU | 52.0 LD | 8.3 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