When And Where To See The Two Green Comets

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Two green comets will shine together — possibly to the naked eye — around Oct. 20-21 as the Orionid meteor shower peaks. However, if you want a preview, comets Lemmon (C/2025 A6) and SWAN (C/2025 R2) are now visible from the Northern Hemisphere in binoculars or a small telescope. Here’s how to find them on Friday, Oct. 10, 2025.

Comet C/2023 A3 (Tsuchinshan-ATLAS) streaks across the sky on October 23, 2024 in Lhasa, Xizang Autonomous Region of China. (Photo by Jiang Feibo/China News Service/VCG via Getty Images)

China News Service via Getty ImagesKey Facts

Of the two, Comet Lemmon is currently the brightest. It last entered the inner solar system about 1,350 years ago and will do so again around the year 3175. Comet SWAN takes about 22,554 years to orbit the sun and will next visit in the year 24,579. They are the first comets visible in binoculars since Comet Tsuchinshan-ATLAS in October 2024.

A dark sky to the north and west is best for seeing the comets. On Friday, Comet Lemmon will be visible before sunrise in the northeast, close to the Big Dipper, while an 86%-lit waning gibbous moon shines in the west. Comet SWAN will be low in the southwest after sunset.

In a pair of binoculars, the comets appear as a small, diffuse patch that changes position slightly each day. Comet Lemmon is moving very quickly and by early next week will also be visible in the post-sunset night sky.

Over the next two weeks, both comets are forecast to become brighter as they both reach their closest to Earth around Oct. 20-23.

A finder chart for Comet Lemmon for Oct. 10, 2025, and for the following two weeks, courtesy from In-The-Sky.org.

In-The-Sky.com (used with permission)Comet Lemmon: When And Where To Find It On Friday, Oct. 10, 2025.

Distance from the sun: 78.3 million miles (126 million kilometers)

Distance from Earth: 70.7 million miles (113.8 million kilometers)

On Friday, Oct. 10, 2025, Comet Lemmon will be visible in the northeast before dawn to the right-hand side of the Big Dipper, low in the sky but observable in binoculars. It will be roughly halfway between the stars Dubhe and Merak on the outside of the Big Dipper’s bowl, and bright star Regulus in the constellation Leo, according to finder charts on In-The-Sky.com.

Comet Lemmon: When And Where To Find It On Friday, Oct. 10, 2025.

StellariumComet Lemmon: Best Time To Look

The best time to look for Comet Lemmon will be a 30-minute window beginning about 90 minutes before sunrise where you are. For New York City, sunrise is 7:02 a.m. EDT, so the ideal viewing time will be 5:32-6:02 a.m. EDT (Venus will rise in the east during this time), although you can look earlier. The comet’s height above the horizon will vary depending on your location, but from New York, it will be around 30 degrees up (about the width of the span of your hand, with fingers stretched out, held at arm’s length) and rising. In addition to fighting the increasing light of dawn, on Thursday, there’s also the light of the 86%-lit waning gibbous moon, setting in the west, to contend with.

A finder chart for Comet SWAN R2 for Oct. 10, 2025, and for the following two weeks, courtesy from In-The-Sky.org.

In-The-Sky.com (used with permission)Comet Swan: When And Where To Find It On Friday, Oct. 10, 2025.

Distance from the sun: 76.1 million miles (122.4 million kilometers)

Distance from Earth: 30.4 million miles (48.9 million kilometers)

Blueish-green Comet SWAN — only discovered in September — will be visible in binoculars on Friday, Oct. 10, 2025, low in the southwest after sunset, to the right side of bright star Antares in the constellation Scorpius. It will be in line with the trio of bright stars that outline the head of Scorpius, according to finder charts on In-The-Sky.com.

Comet Swan: When And Where To Find It On Friday, Oct. 10, 2025.

StellariumComet Swan: Best Time To Look

The best time to look for Comet SWAN will be a 30-minute window beginning about 90 minutes after sunset where you are. For New York City, sunset is 6:21 p.m. EDT, so the ideal viewing time will be 7:51-8:21 p.m. EDT. The comet’s height above the horizon will vary depending on your location, but from New York, it will be around 13 degrees up (about the width between your little finger and forefinger held at arm’s length) and sinking.

How Bright Are The Comets?

Comet Lemmon and Comet SWAN are currently shining at mag. 5.8 and mag. 6, respectively, according to the Comet Observations Database, which puts them right on the cusp of naked-eye visibility — though very dark skies would be required. In practice, you’ll need binoculars — preferably 8×42 to 10×50 or similar — or a small telescope (through which you may see hints of a tail about a degree in length). Outbursts or lulls can shift the apparent brightness quickly, so grab a view while you can.

What Jupiter Did To Comet Lemmon

In April 2025, Comet Lemmon passed about 216 million miles (348 million km) from Jupiter. That might sound distant, but the gas giant’s immense gravity tugged on the comet, altering its orbit. According to Space.com, Jupiter drained some of Lemmon’s orbital energy, shortening its period by nearly 200 years. Instead of returning every 1,350 years, it will now loop back in about 1,150 years. Jupiter often acts as a “cosmic gatekeeper,” reshaping the orbits of passing comets — sometimes capturing them, sometimes ejecting them entirely from the solar system.

Check my feed every day this month for a daily “comet tracker” with finder charts and tips for viewing Comet Lemmon and Comet SWAN.

Further ReadingForbesComet Tracker For Thursday: It’s Finally Time To See Rare Twin CometsBy Jamie CarterForbesA Once-In-A-Lifetime Green Comet May Soon Be Visible, Scientists SayBy Jamie CarterForbesSee Rare Sight Of Two Comets As Meteor Shower Peaks — Here’s WhenBy Jamie CarterForbesComet Lemmon: Your Ultimate Viewing Guide To The ‘Comet Of The Year’By Jamie CarterForbesTwo Naked Eye Comets, ‘Harvest Moon’ And Fireballs: October’s Night SkyBy Jamie CarterForbesOrionid Meteor Shower Begins Thursday — When To See It At Its Best With Two CometsBy Jamie CarterForbesI Just Saw And Photographed The Comet — Here’s How You Can TooBy Jamie Carter