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

Comet C/2017 K2 (PANSTARRS) reaches peak brightness

Dominic Ford, Editor
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Comet C/2017 K2 (PANSTARRS) is forecast to reach the brightest point in its 2022 apparition on 1 August. At that time, it will lie at a distance of 2.50 AU from the Sun, and at a distance of 1.87 AU from the Earth.

From Fairfield on 1 August it will become visible around 21:25 (EDT), 36° above your southern horizon, as dusk fades to darkness. It will then sink towards the horizon, setting at 02:01.

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 2022 apparition of C/2017 K2 (PANSTARRS) are as follows:

Date Event
01 Aug 2022Comet C/2017 K2 (PANSTARRS) reaches peak brightness

The table below lists the times when C/2017 K2 (PANSTARRS) will be visible from Fairfield day-by-day through its apparition:

Date Constellation Comet visibility
11 Jul 2022OphiuchusVisible from 21:48 until 02:27
Highest at 22:36, 47° above S horizon
13 Jul 2022OphiuchusVisible from 21:47 until 02:11
Highest at 22:24, 46° above S horizon
15 Jul 2022OphiuchusVisible from 21:45 until 01:56
Highest at 22:12, 45° above S horizon
17 Jul 2022OphiuchusVisible from 21:43 until 01:41
Highest at 22:00, 44° above S horizon
19 Jul 2022OphiuchusVisible from 21:41 until 01:25
Highest at 21:49, 43° above S horizon
21 Jul 2022OphiuchusVisible from 21:39 until 01:10
Highest at 21:39, 42° above S horizon
23 Jul 2022OphiuchusVisible from 21:37 until 00:54
Highest at 21:37, 41° above S horizon
25 Jul 2022OphiuchusVisible from 21:35 until 00:39
Highest at 21:35, 40° above S horizon
27 Jul 2022OphiuchusVisible from 21:32 until 00:23
Highest at 21:32, 39° above S horizon
29 Jul 2022OphiuchusVisible from 21:29 until 00:08
Highest at 21:29, 38° above S horizon
31 Jul 2022OphiuchusVisible from 21:27 until 23:52
Highest at 21:27, 37° above S horizon
02 Aug 2022OphiuchusVisible from 21:24 until 23:37
Highest at 21:24, 36° above S horizon
04 Aug 2022ScorpiusVisible from 21:21 until 23:22
Highest at 21:21, 35° above S horizon
06 Aug 2022ScorpiusVisible from 21:18 until 23:06
Highest at 21:18, 33° above S horizon
08 Aug 2022ScorpiusVisible from 21:15 until 22:51
Highest at 21:15, 32° above S horizon
10 Aug 2022ScorpiusVisible from 21:12 until 22:35
Highest at 21:12, 31° above SW horizon
12 Aug 2022ScorpiusVisible from 21:08 until 22:20
Highest at 21:08, 29° above SW horizon
14 Aug 2022ScorpiusVisible from 21:05 until 22:05
Highest at 21:05, 28° above SW horizon
16 Aug 2022ScorpiusVisible from 21:02 until 21:49
Highest at 21:02, 27° above SW horizon
18 Aug 2022ScorpiusVisible from 20:58 until 21:34
Highest at 20:58, 26° above SW horizon
20 Aug 2022ScorpiusVisible from 20:55 until 21:18
Highest at 20:55, 24° above SW horizon

A more detailed table of C/2017 K2 (PANSTARRS)'s position on each night is available here. A diagram of the orbit of C/2017 K2 (PANSTARRS) is available here.

Finder chart

The chart below shows the path of C/2017 K2 (PANSTARRS) 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 9 on 1 August 2022. 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 1 August 2022 will be:

Object Right Ascension Declination Constellation Magnitude
Comet C/2017 K2 (PANSTARRS) 16h26m20s 10°57'S Ophiuchus 8.9

The coordinates are given in J2000.0.

The sky on 01 Aug 2022

The sky on 01 August 2022
Twilight ends
Twilight begins

4-day old moon
Waxing Crescent


4 days old

Rise Culm. Set
Mercury 07:08 14:03 20:58
Venus 03:59 11:27 18:54
Moon 09:24 16:00 22:26
Mars 00:17 07:17 14:17
Jupiter 22:36 04:46 10:56
Saturn 20:46 01:55 07:03
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 19 Feb 2023.

Image credit

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






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