Skip to content
Public Universe
Asteroid Near-Earth

2021 BJ1

Add to an observing list or journal →

(2021 BJ1)

Where is it now

Distance from Sun
0.886 AU
True anomaly
122.98°
Distance from Earth
0.22 AU
As of
19 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 BJ1 — 0.886 AU from the Sun 2021 BJ1
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 BJ1 is 0.22 AU from Earth today (1.8 light-minutes).

In the sky

Right ascension
10h 42m 46s
Declination
-52° 10′ 35″
Constellation
Vela
Distance from Earth
0.22 AU
Elongation from the Sun
54.91° — 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.

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
0.837 AU
Eccentricity
0.4446
Inclination
11.48°
Orbital period
279.7 days
Perihelion
0.465 AU
Aphelion
1.209 AU
Longitude of ascending node
120.45°
Argument of periapsis
145.04°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 11.5 LD
0.0294 AU
Tisserand (Jupiter)
6.92

Orbit quality

Orbit poorly determined (uncertainty code 6).

Observations used
57
Data arc
20 days
First observed
11 January 2021
Last observed
31 January 2021
Residual RMS
0.42 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
24.4

Discovery & classification

Aten Near-Earth Object

Close approaches 193 on record

Flyby geometry
Ecliptic flyby of 2021 BJ1 at 2026-11-05 18:37 UTC Top-down view of the ecliptic, Earth at the centre, for the 2026-11-05 18:37 UTC close approach of 2021 BJ1. Catalogue miss distance 76.8 LD · 2.95 × 10⁷ km. The curve is the geocentric path from 2026-11-02 to 2026-11-08, 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 south of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 3 Nov 76.8 LD · 2.95 × 10⁷ km 2026-11-05 18:37 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2026-11-05 18:37 UTC close approach of 2021 BJ1. Catalogue miss distance 76.8 LD · 2.95 × 10⁷ km. The curve is the geocentric path from 2026-11-02 to 2026-11-08, 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 south 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
2026-11-05 18:37:00 Earth 0.1973 AU 76.8 LD 11.8 km/s
2029-11-13 23:37:00 Earth 0.3836 AU 149.3 LD 23.6 km/s
2031-01-25 01:48:00 Earth 0.1987 AU 77.3 LD 19.6 km/s
2032-10-14 16:59:00 Merc 0.0753 AU 29.3 LD 15.8 km/s
2032-10-14 16:59:00 Mercury 0.0753 AU 29.3 LD 15.8 km/s
2034-01-20 00:55:00 Earth 0.1483 AU 57.7 LD 10.9 km/s
2036-09-15 21:35:00 Earth 0.3812 AU 148.3 LD 10 km/s
2036-12-08 03:04:00 Earth 0.2604 AU 101.3 LD 10.7 km/s
2037-04-22 23:50:00 Earth 0.4939 AU 192.2 LD 16.2 km/s
2039-11-05 15:34:00 Earth 0.2048 AU 79.7 LD 14.9 km/s

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

Sources