Topline
Two comets are becoming brighter in the night sky — and could be on the cusp of naked-eye visibility. Predicted to be at their brightest on Oct. 20-21 during the peak of the Orionid meteor shower, Comet Lemmon (also called C/2025 A6) and Comet SWAN (C/2025 R2) can on Saturday, Oct. 18, 2025, be found about 90 minutes after sunset in the northwest and southwest night sky, respectively — though you’ll need binoculars to see them.
Key Facts
These are the first two comets visible to amateur skywatchers since Comet Tsuchinshan-ATLAS in October 2024.
Comet Lemmon is brighter than Comet SWAN. According to the Comet Observation Database, Comet Lemmon is shining at magnitude +4.9 and Comet SWAN at magnitude +5.9, which makes them both almost bright enough to be seen by the naked eye from a very dark sky site. In practice, a pair of 8×42 or 10×50 binoculars is required to see them from most locations.
Comet SWAN, discovered on Sept. 11, 2025, as it exited from the sun’s glare, can be found beneath the cast Summer Triangle asterism of three bright stars in the southwest after sunset. Now traveling away from the sun, Comet SWAN takes about 22,554 years to complete one orbit.
Comet Lemmon was discovered on Jan. 3, 2025, by the Mount Lemmon Survey near Tucson, Arizona. It can be found close to a bright star called Cor Caroli, close to the Big Dipper in the northern sky, both before sunrise and after sunset. It takes 1,350 Earth-years to complete one orbit of the sun.
The best way to find the location of the comets where you are is to use the finder charts at In-The-Sky.com or stargazing apps such as Sky Guide, Stellarium and SkySafari.
When And Where To See The Comets
The best time to spot Comet Lemmon and Comet SWAN on Saturday, Oct. 18, 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 6:08 p.m. EDT, the ideal time for evening viewing is 7:38-8:08 p.m. EDT.
Comet Lemmon can also be seen before dawn. Look during a 30-minute window beginning about 90 minutes before sunrise. With sunrise at 7:11 a.m. EDT in New York, the best time will be 5:41-6:11 a.m. EDT — though earlier observations may also reveal the comet rising in the northeast.
How To Find Comet Lemmon
Distance from the sun: 66.8 million miles (107.5 million kilometers)
Distance from Earth: 56.6 million miles (91 million kilometers)
Before sunrise, the comet will be in the northeast. The Big Dipper’s handle — which will point down toward the horizon — can be used to find it. Trace the stars of the Big Dipper’s handle in an arc, or banana-shape, to go in a curve about half the distance of the handle. Lemmon will be below the star Cor Caroli, the brightest in the simple two-star constellation of Canes Venatici. From New York, the comet will stand about 10 degrees high — approximately the span of your outstretched fist — at 5:41 a.m. EDT, and will climb higher as dawn approaches. Venus rises at about the same time.
After sunset on Saturday, Oct. 18, look for Comet Lemmon roughly between the curved handle of the Big Dipper and bright star Arcturus farther west. Lemmon will be halfway along a line between the end of the handle and Arcturus. Its height above the horizon varies by location, but from New York it will appear about 14 degrees above the northwest horizon at 7:38 p.m. EDT — roughly the width of four fingers held at arm’s length — and will gradually sink as twilight deepens. Also visible will be a slim 8%-lit waning crescent moon low in the east before dawn.
How To Find Comet Swan
Distance from the sun: 88.5 million miles (142.5 million kilometers)
Distance from Earth: 24.4 million miles (39.2 million kilometers)
Blueish-green Comet SWAN will be visible in binoculars on Saturday, Oct. 18, 2025, low in the southwest after sunset. SWAN will be in the constellation Scutum, above the famous “Teapot” asterism in the constellation Sagittarius. It’s in front of the Milky Way, so expect dense starfields to be visible behind the comet in binoculars. At 7:38 p.m. EDT from New York, it will be around 31 degrees up and sinking into the southwest horizon.
How Bright Are The Comets?
The Comet Observation Database reports Comet Lemmon to be shining at magnitude +5.2 and Comet SWAN a little dimmer at magnitude +5.9. Both have increased significantly in the last few nights, but they are not quite bright enough to be seen with the naked eye.
To see either comet, for now, you’ll need a pair of 8×42 or 10×50 binoculars, or similar, with Comet Lemmon the easiest to see. They will appear as diffuse patches of light, with locations far from streetlights and urban light pollution giving you the best views.
Check my feed every day this month for a daily “comet tracker” with finder charts and tips for viewing Comet Lemmon and Comet SWAN from mid-northern latitudes. Also read How To Photograph The Green Comets, Best Stargazing Apps For Finding The Comets and 25 Dark Sky Parks In The U.S. To See The Comets.
