© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.

C/2020 M3 (ATLAS) at perihelion

Dominic Ford, Editor
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Comet C/2020 M3 (ATLAS) will make its closest approach to the Sun, at a distance of 1.27 AU.

From Fairfield the 2020 apparition of C/2020 M3 (ATLAS) will progress as follows:

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.
26 Oct 2020 – C/2020 M3 (ATLAS) at perihelion
09 Nov 2020 – C/2020 M3 (ATLAS) reaches its brightest
14 Nov 2020 – C/2020 M3 (ATLAS) at perigee
05 Oct 2020EridanusNot observable
07 Oct 2020EridanusNot observable
09 Oct 2020EridanusNot observable
11 Oct 2020EridanusNot observable
13 Oct 2020EridanusVisible from 03:44 until 04:45
Highest at 04:15, 22° above S horizon
15 Oct 2020EridanusVisible from 03:08 until 05:13
Highest at 04:10, 24° above S horizon
17 Oct 2020LepusVisible from 02:42 until 05:30
Highest at 04:06, 25° above S horizon
19 Oct 2020LepusVisible from 02:19 until 05:42
Highest at 04:01, 26° above S horizon
21 Oct 2020LepusVisible from 01:57 until 05:53
Highest at 03:55, 28° above S horizon
23 Oct 2020LepusVisible from 01:41 until 06:06
Highest at 03:53, 29° above S horizon
25 Oct 2020LepusVisible from 01:21 until 06:09
Highest at 03:47, 31° above S horizon
27 Oct 2020LepusVisible from 01:01 until 06:13
Highest at 03:40, 33° above S horizon
29 Oct 2020LepusVisible from 00:45 until 06:13
Highest at 03:37, 35° above S horizon
31 Oct 2020LepusVisible from 00:26 until 06:17
Highest at 03:30, 37° above S horizon
02 Nov 2020OrionVisible from 23:10 until 05:17
Highest at 02:26, 39° above S horizon
04 Nov 2020OrionVisible from 22:50 until 05:21
Highest at 02:18, 41° above S horizon
06 Nov 2020OrionVisible from 22:34 until 05:24
Highest at 02:13, 44° above S horizon
08 Nov 2020OrionVisible from 22:18 until 05:25
Highest at 02:08, 46° above S horizon
10 Nov 2020OrionVisible from 21:58 until 05:29
Highest at 01:58, 49° above S horizon
12 Nov 2020OrionVisible from 21:41 until 05:29
Highest at 01:52, 51° above S horizon
14 Nov 2020OrionVisible from 21:25 until 05:33
Highest at 01:45, 54° above S horizon

A more detailed table of C/2020 M3 (ATLAS)'s position on each night is available here. A diagram of the orbit of C/2020 M3 (ATLAS) is available here.

At the moment of perihelion it will be visible in the morning sky, becoming accessible around 01:15, when it reaches an altitude of 21° above your south-eastern horizon. It will then reach its highest point in the sky at 03:44, 31° above your southern horizon. It will be lost to dawn twilight around 06:09, 22° above your south-western horizon.

Finder chart

The chart below shows the path of C/2020 M3 (ATLAS) over the course of its apparition, as calculated from the orbital elements published by the Minor Planet Center (MPC). It is available for download, either on dark background, in PNG, PDF or SVG formats, or on a light background, in PNG, PDF or SVG formats. It was produced using StarCharter.

Comet brightnesses

Comets are intrinsically highly unpredictable objects, since their brightness depends on the scattering of sunlight from dust particles in the comet's coma and tail. This dust is continually streaming away from the comet's nucleus, and its density at any particular time is governed by the rate of sublimation of the ice in the comet's nucleus, as it is heated by the Sun's rays. It also depends on the amount of dust that is mixed in with that ice. This is very difficult to predict in advance, and can be highly variable even between successive apparitions of the same comet.

In consequence, while the future positions of comets are usually known with a high degree of confidence, their future brightnesses are not. For most comets, we do not publish any magnitude estimates at all. For the few comets where we do make estimates, we generally prefer the BAA's magnitude parameters to those published by the Minor Planet Center, since they are typically updated more often.

Based on the magnitude parameters published for this comet by the BAA Comet Section, we estimate that it may be around mag 8 at perihelion. This estimate is based on observations that the BAA has received from amateur astronomers, assuming that its current level of activity will remain constant.

This comet is not expected to be visible to the naked eye, but might be visible through bird-watching binoculars.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet C/2020 M3 (ATLAS) 05h09m20s -17°21' Lepus 8.4

The coordinates are given in J2000.0.

The sky on 26 October 2020
Twilight ends
Twilight begins

10-day old moon
Waxing Gibbous


10 days old

Rise Culm. Set
Mercury 07:13 12:30 17:47
Venus 04:16 10:27 16:38
Moon 16:15 21:40 02:14
Mars 17:20 23:40 06:00
Jupiter 13:20 17:59 22:38
Saturn 13:40 18:23 23:07
All times shown in EDT.


This event was automatically generated on the basis of orbital elements published by the Minor Planet Center (MPC) , and is updated whenever new elements become available. It was last updated on 26 Mar 2021.

Image credit

© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.






Color scheme