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Comet

ATLAS

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478P/ATLAS

Where is it now

Distance from Sun
4.613 AU
True anomaly
151.72°
Distance from Earth
4.834 AU
As of
22 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.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.995 AU from the Sun Earth ATLAS — 4.613 AU from the Sun ATLAS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. ATLAS is 4.834 AU from Earth today (40.2 light-minutes).

In the sky

Right ascension
18h 45m 30s
Declination
-19° 55′ 25″
Constellation
Sagittarius
Distance from Earth
4.84 AU
Elongation from the Sun
71.02° — 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
3.647 AU
Eccentricity
0.3436
Inclination
12.52°
Orbital period
6.97 years
Perihelion
2.394 AU
Aphelion
4.901 AU
Longitude of ascending node
127.28°
Argument of periapsis
13.11°
Epoch · J2000
2460162.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 548.9 LD
1.4105 AU
Tisserand (Jupiter)
2.962

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
494
Data arc
8.69 years
First observed
18 September 2015
Last observed
27 May 2024
Residual RMS
0.51 ″
Solution · Otto Matic
10 October 2024

Visual & observation

Absolute magnitude (H)
10
Total magnitude M₁ · K₁ 19.5
10

Discovery & classification

Also known as 478P · 478P/2017 BQ100 · 478P/2023 Y3

Named

Close approaches 6 on record

When (UTC) Body Distance Lunar distances Relative speed
2068-08-29 18:48:00 Juptr 1.8469 AU 718.8 LD 8.5 km/s
2104-02-25 07:13:00 Juptr 1.3647 AU 531.1 LD 7 km/s
2164-03-05 06:53:00 Juptr 0.977 AU 380.2 LD 5 km/s

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

Sources