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Asteroid Near-Earth

2021 XO3

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(2021 XO3)

Where is it now

Distance from Sun
0.983 AU
True anomaly
154.22°
Distance from Earth
0.539 AU
As of
15 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 — 0.997 AU from the Sun Earth 2021 XO3 — 0.983 AU from the Sun 2021 XO3
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 XO3 is 0.539 AU from Earth today (4.5 light-minutes).

In the sky

Right ascension
08h 41m 46s
Declination
+10° 27′ 34″
Constellation
Cancer
Distance from Earth
0.54 AU
Elongation from the Sun
73.4° — 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.

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
0.725 AU
Eccentricity
0.4836
Inclination
4.94°
Orbital period
225.3 days
Perihelion
0.374 AU
Aphelion
1.075 AU
Longitude of ascending node
110.13°
Argument of periapsis
149.3°
Epoch · J2000
2459555.5
Orbit class · ATE
Aten
Earth MOID · 2.7 LD
0.007 AU
Tisserand (Jupiter)
7.831

Orbit quality

Orbit very uncertain — the object may be effectively lost (uncertainty code 8).

Observations used
24
Data arc
4 days
First observed
6 December 2021
Last observed
10 December 2021
Residual RMS
0.47 ″
Solution · Otto Matic
10 December 2021

Visual & observation

Absolute magnitude (H)
24.85

Discovery & classification

Aten Near-Earth Object

Close approaches 58 on record

Flyby geometry
Ecliptic flyby of 2021 XO3 at 2027-01-07 22:59 UTC Top-down view of the ecliptic, Earth at the centre, for the 2027-01-07 22:59 UTC close approach of 2021 XO3. Catalogue miss distance 34.7 LD · 1.33 × 10⁷ km. The curve is the geocentric path from 2027-01-04 to 2027-01-10, 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 34.7 LD · 1.33 × 10⁷ km 2027-01-07 22:59 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2027-01-07 22:59 UTC close approach of 2021 XO3. Catalogue miss distance 34.7 LD · 1.33 × 10⁷ km. The curve is the geocentric path from 2027-01-04 to 2027-01-10, 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
2027-01-07 22:59:00 Earth 0.0891 AU 34.7 LD 14.6 km/s
2027-03-04 00:57:00 Merc 0.0251 AU 9.8 LD 27.3 km/s
2027-03-04 00:57:00 Mercury 0.0251 AU 9.8 LD 27.3 km/s
2031-12-27 13:41:00 Earth 0.4561 AU 177.5 LD 27.4 km/s
2032-11-26 00:14:00 Earth 0.4491 AU 174.8 LD 26.9 km/s
2055-09-13 23:03:00 Venus 0.0568 AU 22.1 LD 15.3 km/s
2056-01-07 17:15:00 Earth 0.0528 AU 20.5 LD 13.3 km/s
2056-04-25 18:48:00 Venus 0.0536 AU 20.8 LD 15.5 km/s
2056-10-16 05:08:00 Merc 0.0447 AU 17.4 LD 29.8 km/s
2056-10-16 05:08:00 Mercury 0.0447 AU 17.4 LD 29.8 km/s

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

Sources