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Asteroid Near-Earth

2021 LJ4

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(2021 LJ4)

Where is it now

Distance from Sun
0.895 AU
True anomaly
158.05°
Distance from Earth
1.545 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 LJ4 — 0.895 AU from the Sun 2021 LJ4
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 LJ4 is 1.545 AU from Earth today (12.8 light-minutes).

In the sky

Right ascension
11h 18m 12s
Declination
+00° 55′ 41″
Constellation
Leo
Distance from Earth
1.55 AU
Elongation from the Sun
33.2° — 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
0.676 AU
Eccentricity
0.382
Inclination
9.82°
Orbital period
203.2 days
Perihelion
0.418 AU
Aphelion
0.935 AU
Longitude of ascending node
277.54°
Argument of periapsis
56.65°
Epoch · J2000
2461200.5
Orbit class · IEO
Atira (interior-Earth object)
Earth MOID · 49.7 LD
0.1278 AU
Tisserand (Jupiter)
8.349

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
26
Data arc
7.83 years
First observed
5 March 2016
Last observed
3 January 2024
Residual RMS
0.42 ″
Solution · Otto Matic
5 January 2024

Visual & observation

Absolute magnitude (H)
20.11

Discovery & classification

Atira Near-Earth Object

Close approaches 285 on record

Flyby geometry
Ecliptic flyby of 2021 LJ4 at 2028-11-22 18:14 UTC Top-down view of the ecliptic, Earth at the centre, for the 2028-11-22 18:14 UTC close approach of 2021 LJ4. Catalogue miss distance 168.1 LD · 6.46 × 10⁷ km. The curve is the geocentric path from 2028-11-19 to 2028-11-25, 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 168.1 LD · 6.46 × 10⁷ km 2028-11-22 18:14 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2028-11-22 18:14 UTC close approach of 2021 LJ4. Catalogue miss distance 168.1 LD · 6.46 × 10⁷ km. The curve is the geocentric path from 2028-11-19 to 2028-11-25, 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
2028-03-14 23:04:00 Merc 0.0523 AU 20.4 LD 14.8 km/s
2028-03-14 23:04:00 Mercury 0.0523 AU 20.4 LD 14.8 km/s
2028-11-22 18:14:00 Earth 0.432 AU 168.1 LD 9.8 km/s
2029-02-26 06:35:00 Earth 0.3894 AU 151.5 LD 17.6 km/s
2030-02-09 01:16:00 Earth 0.2625 AU 102.1 LD 14.8 km/s
2030-05-04 16:18:00 Earth 0.3796 AU 147.7 LD 5.7 km/s
2033-11-29 05:56:00 Earth 0.4115 AU 160.1 LD 8.5 km/s
2034-02-27 13:23:00 Earth 0.3564 AU 138.7 LD 16.2 km/s
2035-02-10 18:10:00 Earth 0.2962 AU 115.3 LD 16 km/s
2035-05-13 02:54:00 Earth 0.4002 AU 155.7 LD 7.7 km/s

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

Sources