In the evening sky, 10P/Tempel remains the brightest comet, beginning September near magnitude 8.2 and fading to about magnitude 9.2 by month’s end and magnitude 11 by late October. 220P/McNaught is also of interest following its strong August outburst, which briefly brought it to 6th magnitude and produced a tail nearly 2 degrees long. A morning-sky object, it begins September near magnitude 10 and should remain around 10th to 11th magnitude through October. Its predicted brightness is uncertain due to post-outburst fading, and additional outbursts are possible.

Also worth watching is 161P/Hartley-IRAS, which should brighten from magnitude 13.5 in early September to about magnitude 11 by month’s end and remain near 10th to 11th magnitude through October. It is a morning object in September, becoming an evening target after passing opposition late in the month. Low-activity 169P/NEAT is predicted to reach magnitude 10 near its September 21 perihelion, though its small solar elongation makes it a difficult morning target.

The monthly ALPO Comet News PDF can be found here. All are encouraged to join the discussion over at Cloudy Nights at https://www.cloudynights.com/forums/topic/1009401-alpo-comet-news-for-september-and-october-2026

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10P/Tempel remains the brightest comet in the sky this August. Recent observations place it at magnitude 7.5. Images of the comet have revealed a strong dust trail extending across tens of degrees. Although an orbit plane crossing occurred in July, the dust trail should remain visible throughout August. With perihelion on August 2, comet Tempel starts August near its brightest and will slowly fade to magnitude 8.1 by the end of the month.

Also of interest in August is the low-activity comet 169P/NEAT, which will be well placed for northern hemisphere observers during the first half of the month as it brightens to ~10th magnitude. Another target for imagers is the long-period comet C/2023 R1 (PANSTARRS), currently at 12-13th magnitude and accompanied by a fainter secondary component.

The monthly ALPO Comet News PDF can be found here. All are encouraged to join the discussion over at Cloudy Nights at https://www.cloudynights.com/forums/topic/1006751-alpo-comet-news-for-august-2026

The brightest comet this month is short-period 10P/Tempel, which is well placed as it approaches an early August opposition. This month, it should brighten from about magnitude 9.3 to near its peak at 7.8. At 12th magnitude and fainter are departing C/2025 R3 (PANSTARRS), visible only from the southern hemisphere, and short-period 88P/Howell and outbursting 220P/McNaught. Incoming is low-activity 169P/NEAT, which will brighten from 16th to 13th magnitude this month.

The monthly ALPO Comet News PDF can be found here. All are encouraged to join the discussion over at Cloudy Nights at https://www.cloudynights.com/forums/topic/1004270-alpo-comet-news-for-july-2026