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Have you seen the green comets yet? Two icy visitors from the edge of the solar system — Comet Lemmon (C/2025 A6) and Comet SWAN (C/2025 R2) — are the first comets visible in binoculars since Comet Tsuchinshan-ATLAS in October 2024. Both are visible after sunset on Wednesday, Oct. 22, 2025, from the Northern Hemisphere, remaining near their brightest in the night sky. It’s an especially good night to catch Comet Lemmon, which will sit just to the right of Izar in the constellation Boötes, above the orange star Arcturus. Comet SWAN glows directly below Altair, the uppermost star of the Summer Triangle.
Comet Lemmon (C/2025 A6) as imaged by Gianluca Masi at The Virtual Telescope Project (www.virtualtelescope.eu).
Gianluca Masi at The Virtual Telescope Project (www.virtualtelescope.eu).Key Facts
Although both Lemmon and SWAN reached their brightest on Monday, Oct. 20, when they reached their closest to Earth at 55 and 24 million miles, respectively, they are likely to remain at their brightest on Wednesday, Oct. 22.
The comets are visible in the northwest (Lemmon) and southwest (SWAN) about 90 minutes after sunset. Lemmon is moving quickly across the sky west of the Big Dipper, close to bright star Arcturus, while SWAN is beneath the three bright stars that comprise the Summer Triangle.
The best way to find the comets is stargazing apps such as Sky Guide, Stellarium and SkySafari, or the finder charts at In-The-Sky.com.
Comet Lemmon and Comet SWAN are most easily seen using binoculars and away from light pollution in a Dark Sky Place (or somewhere that looks dark on a light pollution map). You may be able to see them with the naked eye, but binoculars will be required to see their tails.
Increasing moonlight will make both comets harder to see by the weekend, by which time both will have faded slightly, which makes this week the time to look. As always, comets can have a surprise outburst and brighten or a sudden disintegration and fade.
How to find Comet Lemmon, 90 minutes after sunset, from Oct. 13-24, 2025.
StellariumWhen And Where To See The Comets
The best time to spot Comet Lemmon and Comet SWAN on Wednesday, Oct. 22, is during a 30-minute window starting about 90 minutes after sunset where you are. Both are visible after sunset but in opposite parts of the sky — Lemmon in the northwest, SWAN in the southwest. For New York City, where sunset is at 6:02 p.m. EDT, the ideal time for evening viewing is 7:32-8:02 p.m. EDT. A 2%-lit waxing crescent moon sets early, barely even noticed, leaving a dark sky ideal for spotting the comets.
Where to find Comet Lemmon after sunset on Oct. 22, 2025.
Stellarium
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