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Asteroid Near-Earth

2021 RH

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(2021 RH)

Where is it now

Distance from Sun
0.891 AU
True anomaly
317.03°
Distance from Earth
1.621 AU
As of
22 October 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.

Sun Earth — 0.995 AU from the Sun Earth 2021 RH — 0.891 AU from the Sun 2021 RH
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 RH is 1.621 AU from Earth today (13.5 light-minutes).

In the sky

Right ascension
12h 01m 01s
Declination
-02° 20′ 27″
Constellation
Virgo
Distance from Earth
1.62 AU
Elongation from the Sun
28.86° — near the Sun — look low at dusk or dawn

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.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

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
0.955 AU
Eccentricity
0.0876
Inclination
15.49°
Orbital period
341.1 days
Perihelion
0.872 AU
Aphelion
1.039 AU
Longitude of ascending node
162.11°
Argument of periapsis
28.13°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 7.1 LD
0.0181 AU
Tisserand (Jupiter)
6.269

Orbit quality

Orbit reasonably well determined (uncertainty code 5).

Observations used
136
Data arc
5 days
First observed
2 September 2021
Last observed
7 September 2021
Residual RMS
0.42 ″
Solution · Otto Matic
26 October 2025

Visual & observation

Absolute magnitude (H)
25.78

Discovery & classification

Aten Near-Earth Object

Close approaches 35 on record

Flyby geometry
Ecliptic flyby of 2021 RH at 2035-09-03 16:55 UTC Top-down view of the ecliptic, Earth at the centre, for the 2035-09-03 16:55 UTC close approach of 2021 RH. Catalogue miss distance 21.1 LD · 8.11 × 10⁶ km. The curve is the geocentric path from 2035-08-31 to 2035-09-06, 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. Sun 21.1 LD · 8.11 × 10⁶ km 2035-09-03 16:55 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2035-09-03 16:55 UTC close approach of 2021 RH. Catalogue miss distance 21.1 LD · 8.11 × 10⁶ km. The curve is the geocentric path from 2035-08-31 to 2035-09-06, 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.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2035-09-03 16:55:00 Earth 0.0542 AU 21.1 LD 8.5 km/s
2036-03-08 12:03:00 Earth 0.1251 AU 48.7 LD 9 km/s
2049-09-03 02:56:00 Earth 0.1837 AU 71.5 LD 10.7 km/s
2050-09-11 17:34:00 Earth 0.1973 AU 76.8 LD 8.9 km/s
2051-02-01 22:45:00 Earth 0.1942 AU 75.6 LD 10.4 km/s
2064-09-05 06:38:00 Earth 0.0703 AU 27.4 LD 7.9 km/s
2065-02-18 21:51:00 Earth 0.1167 AU 45.4 LD 9.3 km/s
2078-09-04 05:59:00 Earth 0.0197 AU 7.7 LD 8.1 km/s
2079-02-27 08:46:00 Earth 0.1096 AU 42.7 LD 9.1 km/s
2092-09-04 00:19:00 Earth 0.0274 AU 10.6 LD 8 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources