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Asteroid Near-Earth

2021 AB1

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(2021 AB1)

Where is it now

Distance from Sun
1.041 AU
True anomaly
194.86°
Distance from Earth
1.719 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 AB1 — 1.041 AU from the Sun 2021 AB1
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 AB1 is 1.719 AU from Earth today (14.3 light-minutes).

In the sky

Right ascension
11h 28m 56s
Declination
+06° 56′ 58″
Constellation
Leo
Distance from Earth
1.71 AU
Elongation from the Sun
33.35° — 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
0.732 AU
Eccentricity
0.463
Inclination
9.06°
Orbital period
228.6 days
Perihelion
0.393 AU
Aphelion
1.071 AU
Longitude of ascending node
101.38°
Argument of periapsis
201.68°
Epoch · J2000
2459219.5
Orbit class · ATE
Aten
Earth MOID · 4.3 LD
0.0111 AU
Tisserand (Jupiter)
7.768

Orbit quality

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

Observations used
21
Data arc
2 days
First observed
4 January 2021
Last observed
6 January 2021
Residual RMS
0.41 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
26.7

Discovery & classification

Aten Near-Earth Object

Close approaches 69 on record

Flyby geometry
Ecliptic flyby of 2021 AB1 at 2028-02-14 17:41 UTC Top-down view of the ecliptic, Earth at the centre, for the 2028-02-14 17:41 UTC close approach of 2021 AB1. Catalogue miss distance 114.1 LD · 4.39 × 10⁷ km. The curve is the geocentric path from 2028-02-11 to 2028-02-17, 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 114.1 LD · 4.39 × 10⁷ km 2028-02-14 17:41 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2028-02-14 17:41 UTC close approach of 2021 AB1. Catalogue miss distance 114.1 LD · 4.39 × 10⁷ km. The curve is the geocentric path from 2028-02-11 to 2028-02-17, 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
2028-02-14 17:41:00 Earth 0.2933 AU 114.1 LD 20 km/s
2028-11-17 17:40:00 Merc 0.0986 AU 38.4 LD 28.4 km/s
2028-11-17 17:40:00 Mercury 0.0986 AU 38.4 LD 28.4 km/s
2030-12-27 19:48:00 Earth 0.0939 AU 36.5 LD 14.5 km/s
2032-01-06 11:47:00 Merc 0.0813 AU 31.6 LD 25.9 km/s
2032-01-06 11:47:00 Mercury 0.0813 AU 31.6 LD 25.9 km/s
2033-02-16 03:42:00 Earth 0.2233 AU 86.9 LD 17.2 km/s
2033-11-01 01:38:00 Venus 0.1415 AU 55.1 LD 23 km/s
2034-06-16 11:15:00 Venus 0.083 AU 32.3 LD 18.8 km/s
2035-01-29 05:44:00 Venus 0.0863 AU 33.6 LD 14.8 km/s

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

Sources