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Comet

ATLAS

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C/2018 A3 (ATLAS)

ATLAS is a comet in the Comet orbit class. Its orbit takes it from 3.28 AU to 988.63 AU from the Sun; one orbit takes 11,045.1 years. Orbit from the JPL solution of 15 April 2021.

Where is it now

Distance from Sun
19.226 AU
True anomaly
131.66°
Distance from Earth
18.643 AU
As of
25 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 — 19.226 AU from the Sun ATLAS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. ATLAS is 18.643 AU from Earth today (2.6 light-hours).

In the sky

Right ascension
23h 31m 09s
Declination
-29° 47′ 31″
Constellation
Sculptor
Distance from Earth
18.65 AU
Elongation from the Sun
124.46° — well clear of the Sun

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
495.954 AU
Eccentricity
0.9934
Inclination
139.56°
Orbital period
11,045.1 years
Perihelion
3.277 AU
Aphelion
988.631 AU
Longitude of ascending node
194.28°
Argument of periapsis
86.43°
Epoch · J2000
2458459.5
Orbit class · COM
Comet
Earth MOID · 1,013.8 LD
2.605 AU
Tisserand (Jupiter)
-1.695

Orbit quality

Observations used
1,589
Data arc
2.79 years
First observed
10 January 2018
Last observed
24 October 2020
Residual RMS
0.5 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
9.4
Total magnitude M₁ · K₁ 9
9.4

Discovery & classification

Also known as 2018 A3

Named

Sources