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Comet

ATLAS

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P/2021 J3 (ATLAS)

Where is it now

Distance from Sun
10.991 AU
True anomaly
141.42°
Distance from Earth
10.059 AU
As of
24 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 — 0.994 AU from the Sun Earth ATLAS — 10.991 AU from the Sun ATLAS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. ATLAS is 10.059 AU from Earth today (1.4 light-hours).

In the sky

Right ascension
01h 26m 44s
Declination
-08° 05′ 00″
Constellation
Cetus
Distance from Earth
10.06 AU
Elongation from the Sun
158.5° — 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
8.933 AU
Eccentricity
0.4508
Inclination
14.57°
Orbital period
26.7 years
Perihelion
4.906 AU
Aphelion
12.96 AU
Longitude of ascending node
111.24°
Argument of periapsis
125.69°
Epoch · J2000
2459405.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 1,525.7 LD
3.9203 AU
Tisserand (Jupiter)
2.846

Orbit quality

Orbit reasonably well determined (uncertainty code 5).

Observations used
145
Data arc
119 days
First observed
13 May 2021
Last observed
9 September 2021
Residual RMS
0.45 ″
Solution · Otto Matic
19 March 2024

Visual & observation

Absolute magnitude (H)
6.9
Total magnitude M₁ · K₁ 10.8
6.9

Discovery & classification

Also known as 2021 J3

Named

Sources