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Asteroid Near-Earth

2021 JJ4

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(2021 JJ4)

Where is it now

Distance from Sun
0.948 AU
True anomaly
126.8°
Distance from Earth
1.943 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 JJ4 — 0.948 AU from the Sun 2021 JJ4
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 JJ4 is 1.943 AU from Earth today (16.2 light-minutes).

In the sky

Right ascension
13h 31m 58s
Declination
-10° 37′ 57″
Constellation
Virgo
Distance from Earth
1.95 AU
Elongation from the Sun
2.06° — too close to the Sun to observe

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
0.854 AU
Eccentricity
0.3477
Inclination
4.49°
Orbital period
288.1 days
Perihelion
0.557 AU
Aphelion
1.151 AU
Longitude of ascending node
228.87°
Argument of periapsis
206.91°
Epoch · J2000
2459343.5
Orbit class · ATE
Aten
Earth MOID · 8.4 LD
0.0215 AU
Tisserand (Jupiter)
6.852

Orbit quality

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

Observations used
9
Data arc
3 days
First observed
8 May 2021
Last observed
11 May 2021
Residual RMS
0.49 ″
Solution · Otto Matic
11 May 2021

Visual & observation

Absolute magnitude (H)
26.13

Discovery & classification

Aten Near-Earth Object

Close approaches 27 on record

Flyby geometry
Ecliptic flyby of 2021 JJ4 at 2029-07-18 15:26 UTC Top-down view of the ecliptic, Earth at the centre, for the 2029-07-18 15:26 UTC close approach of 2021 JJ4. Catalogue miss distance 58.8 LD · 2.26 × 10⁷ km. The curve is the geocentric path from 2029-07-15 to 2029-07-21, 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 58.8 LD · 2.26 × 10⁷ km 2029-07-18 15:26 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2029-07-18 15:26 UTC close approach of 2021 JJ4. Catalogue miss distance 58.8 LD · 2.26 × 10⁷ km. The curve is the geocentric path from 2029-07-15 to 2029-07-21, 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
2029-07-18 15:26:00 Earth 0.1512 AU 58.8 LD 12.7 km/s
2032-04-28 11:23:00 Earth 0.2685 AU 104.5 LD 17.1 km/s
2033-07-06 19:52:00 Earth 0.4526 AU 176.2 LD 22.6 km/s
2033-10-21 03:49:00 Venus 0.1117 AU 43.5 LD 14.6 km/s
2044-07-16 10:39:00 Earth 0.208 AU 80.9 LD 14.7 km/s
2047-04-26 12:18:00 Earth 0.1932 AU 75.2 LD 14.7 km/s
2058-05-05 05:38:00 Earth 0.4212 AU 163.9 LD 21.9 km/s
2059-07-13 07:07:00 Earth 0.3096 AU 120.5 LD 18 km/s
2062-04-23 13:10:00 Earth 0.0882 AU 34.3 LD 11.4 km/s
2070-07-20 01:52:00 Earth 0.0855 AU 33.3 LD 9.9 km/s

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

Sources