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

Comet 67P/Churyumov-Gerasimenko reaches peak brightness

Dominic Ford, Editor
From the Comets feed

Please wait
Loading 0/4
Click and drag to rotate
Mouse wheel to zoom in/out
Touch with mouse to dismiss
The sky at

Comet 67P/Churyumov-Gerasimenko is forecast to reach the brightest point in its 2021 apparition on 7 November. At that time, it will lie at a distance of 1.21 AU from the Sun, and at a distance of 0.42 AU from the Earth.

From Fairfield on 7 November it will be visible in the morning sky, becoming accessible around 23:54, when it reaches an altitude of 21° above your eastern horizon. It will then reach its highest point in the sky at 04:27, 75° above your southern horizon. It will be lost to dawn twilight around 05:21, 71° above your south-western horizon.

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.

The events that comprise the 2021 apparition of 67P/Churyumov-Gerasimenko are as follows:

Date Event
02 Nov 2021Comet 67P/Churyumov-Gerasimenko passes perihelion
07 Nov 2021Comet 67P/Churyumov-Gerasimenko reaches peak brightness
11 Nov 2021Comet 67P/Churyumov-Gerasimenko passes perigee

The table below lists the times when 67P/Churyumov-Gerasimenko will be visible from Fairfield day-by-day through its apparition:

Date Constellation Comet visibility
17 Oct 2021GeminiVisible from 23:57 until 05:59
Highest at 05:24, 74° above S horizon
19 Oct 2021GeminiVisible from 23:57 until 06:01
Highest at 05:25, 74° above S horizon
21 Oct 2021GeminiVisible from 23:57 until 06:03
Highest at 05:26, 74° above S horizon
23 Oct 2021GeminiVisible from 23:58 until 06:05
Highest at 05:27, 74° above S horizon
25 Oct 2021GeminiVisible from 23:58 until 06:07
Highest at 05:28, 75° above S horizon
27 Oct 2021GeminiVisible from 23:58 until 06:09
Highest at 05:29, 75° above S horizon
29 Oct 2021GeminiVisible from 23:58 until 06:12
Highest at 05:29, 75° above S horizon
31 Oct 2021GeminiVisible from 23:58 until 06:14
Highest at 05:29, 75° above S horizon
02 Nov 2021GeminiVisible from 23:57 until 06:16
Highest at 05:30, 75° above S horizon
04 Nov 2021GeminiVisible from 23:57 until 06:18
Highest at 05:29, 75° above S horizon
06 Nov 2021GeminiVisible from 23:56 until 06:20
Highest at 05:29, 75° above S horizon
08 Nov 2021GeminiVisible from 22:55 until 05:22
Highest at 04:28, 76° above S horizon
10 Nov 2021GeminiVisible from 22:54 until 05:24
Highest at 04:27, 76° above S horizon
12 Nov 2021GeminiVisible from 22:53 until 05:27
Highest at 04:26, 76° above S horizon
14 Nov 2021CancerVisible from 22:51 until 05:29
Highest at 04:24, 76° above S horizon
16 Nov 2021CancerVisible from 22:49 until 05:31
Highest at 04:22, 76° above S horizon
18 Nov 2021CancerVisible from 22:47 until 05:33
Highest at 04:20, 76° above S horizon
20 Nov 2021CancerVisible from 22:44 until 05:35
Highest at 04:18, 76° above S horizon
22 Nov 2021CancerVisible from 22:41 until 05:37
Highest at 04:15, 76° above S horizon
24 Nov 2021CancerVisible from 22:37 until 05:39
Highest at 04:11, 76° above S horizon
26 Nov 2021CancerVisible from 22:34 until 05:41
Highest at 04:08, 76° above S horizon

A more detailed table of 67P/Churyumov-Gerasimenko's position on each night is available here. A diagram of the orbit of 67P/Churyumov-Gerasimenko is available here.

Finder chart

The chart below shows the path of 67P/Churyumov-Gerasimenko 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 on 7 November 2021. 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 on 7 November 2021 will be:

Object Right Ascension Declination Constellation Magnitude
Comet 67P/Churyumov-Gerasimenko 07h41m40s 26°36'N Gemini 8.3

The coordinates are given in J2000.0.

The sky on 07 Nov 2021

The sky on 07 November 2021
Twilight ends
Twilight begins

3-day old moon
Waxing Crescent


3 days old

Rise Culm. Set
Mercury 05:23 10:48 16:12
Venus 10:35 14:52 19:09
Moon 09:52 14:27 18:58
Mars 05:39 10:56 16:13
Jupiter 13:16 18:25 23:34
Saturn 12:30 17:23 22:15
All times shown in EST.


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 19 Feb 2023.

Image credit

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






Color scheme