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Asteroid Near-Earth

2021 RF2

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(2021 RF2)

Where is it now

Distance from Sun
0.928 AU
True anomaly
244.8°
Distance from Earth
0.084 AU
As of
20 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 — 0.996 AU from the Sun Earth 2021 RF2 — 0.928 AU from the Sun 2021 RF2
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 RF2 is 0.084 AU from Earth today (42.1 light-seconds).

In the sky

Right ascension
12h 26m 15s
Declination
+18° 32′ 12″
Constellation
Coma Berenices
Distance from Earth
0.09 AU
Elongation from the Sun
34.83° — near the Sun — look low at dusk or dawn

Favours the northern hemisphere; low or below the horizon from far south.

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
0.884 AU
Eccentricity
0.2315
Inclination
4.19°
Orbital period
303.4 days
Perihelion
0.679 AU
Aphelion
1.088 AU
Longitude of ascending node
5.08°
Argument of periapsis
139.98°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 2.1 LD
0.0055 AU
Tisserand (Jupiter)
6.688

Orbit quality

Orbit poorly determined (uncertainty code 6).

Observations used
46
Data arc
29 days
First observed
4 September 2021
Last observed
3 October 2021
Residual RMS
0.61 ″
Solution · Otto Matic
10 December 2021

Visual & observation

Absolute magnitude (H)
25.75

Discovery & classification

Aten Near-Earth Object

Close approaches 84 on record

Flyby geometry
Ecliptic flyby of 2021 RF2 at 2031-03-17 11:02 UTC Top-down view of the ecliptic, Earth at the centre, for the 2031-03-17 11:02 UTC close approach of 2021 RF2. Catalogue miss distance 115.8 LD · 4.45 × 10⁷ km. The curve is the geocentric path from 2031-03-14 to 2031-03-20, 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. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 115.8 LD · 4.45 × 10⁷ km 2031-03-17 11:02 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2031-03-17 11:02 UTC close approach of 2021 RF2. Catalogue miss distance 115.8 LD · 4.45 × 10⁷ km. The curve is the geocentric path from 2031-03-14 to 2031-03-20, 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. 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
2026-10-04 20:18:00 Earth 0.0661 AU 25.7 LD 7.7 km/s
2027-01-03 06:22:00 Venus 0.0408 AU 15.9 LD 5.7 km/s
2029-07-29 00:46:00 Venus 0.1429 AU 55.6 LD 12.5 km/s
2031-03-17 11:02:00 Earth 0.2977 AU 115.8 LD 9.5 km/s
2031-10-02 12:53:00 Earth 0.1832 AU 71.3 LD 11.3 km/s
2035-07-17 02:55:00 Earth 0.4208 AU 163.7 LD 18.3 km/s
2036-02-28 07:27:00 Earth 0.3095 AU 120.5 LD 10.1 km/s
2036-09-27 13:10:00 Earth 0.3008 AU 117.0 LD 14.9 km/s
2040-07-11 13:38:00 Earth 0.3062 AU 119.2 LD 14.7 km/s
2041-02-10 02:43:00 Earth 0.311 AU 121.1 LD 10.1 km/s

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

Sources