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Comet

ATLAS

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C/2020 Y3 (ATLAS)

ATLAS is a comet in the Comet orbit class. Its orbit takes it from 2 AU to 300.16 AU from the Sun; one orbit takes 1,857 years. Orbit from the JPL solution of 4 September 2021.

Where is it now

Distance from Sun
16.331 AU
True anomaly
140.08°
Distance from Earth
15.893 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 — 16.331 AU from the Sun ATLAS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. ATLAS is 15.893 AU from Earth today (2.2 light-hours).

In the sky

Right ascension
21h 35m 04s
Declination
+51° 23′ 46″
Constellation
Cygnus
Distance from Earth
15.9 AU
Elongation from the Sun
114.31° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

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
151.08 AU
Eccentricity
0.9868
Inclination
83.1°
Orbital period
1,857 years
Perihelion
1.999 AU
Aphelion
300.16 AU
Longitude of ascending node
191.43°
Argument of periapsis
342.04°
Epoch · J2000
2459270.5
Orbit class · COM
Comet
Earth MOID · 401.9 LD
1.0328 AU
Tisserand (Jupiter)
0.244

Orbit quality

Observations used
380
Data arc
220 days
First observed
28 December 2020
Last observed
5 August 2021
Residual RMS
0.59 ″
Solution · Otto Matic
4 September 2021

Visual & observation

Absolute magnitude (H)
13.9
Total magnitude M₁ · K₁ 8.8
13.9

Discovery & classification

Also known as 2020 Y3

Named

Sources