Topline
Two comets are becoming visible in the night sky this week, with experts predicting they will become even brighter next week during the peak of the Orionid meteor shower. The brightest is Comet Lemmon — also called C/2025 A6 (Lemmon) — which is now making a play for the title of “comet of the year,” as it shines in the northwest beneath the Big Dipper after sunset on Wednesday, Oct. 15, 2025. However, it’s not the only green comet now visible in binoculars for Northern Hemisphere observers, with Comet SWAN (C/2025 R2) also on the cusp of visibility in the southwest after dark. Both comets are likely to brighten as they reach their closest to Earth around Oct. 20-21.
Key Facts
On Wednesday, Oct. 15, 2025, Comet Lemmon will be visible both after sunset and before sunrise close to the Big Dipper, with the best time to look about 90 minutes after dusk.
Comet Lemmon is rapidly approaching Earth, and getting brighter each night, though at its closest on Tuesday, Oct. 21, it will still be 55.4 million miles (89.2 million kilometers) from Earth, so it poses no danger.
It was first discovered on Jan. 3, 2025, by the Mount Lemmon Survey near Tucson, Arizona. Astronomers have since calculated that it takes around 1,350 Earth-years to complete one orbit of the sun, but its close pass to Jupiter on the way into the inner solar system this year has saved some of its energy, according to Space.com, causing its orbit to reduce to 1,150 years.
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.
An easy way to find the location of the comets 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 Wednesday, Oct. 15, 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 6:13 p.m. EDT, the ideal time for evening viewing is 7:43-8:13 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 7:07 a.m. EDT in New York, the best time will be 5:37-6:07 a.m. EDT — though earlier observations may also reveal the comet rising in the northeast.
How To Find Comet Lemmon
Distance from the sun: 71 million miles (114.2 million kilometers)
Distance from Earth: 60.3 million miles (97 million kilometers)
Green comet Lemmon is now moving at about 4 degrees per day, and is currently in the constellation Ursa Major — home to the Big Dipper.
Before sunrise, the comet is visible in the northeast. The Big Dipper’s handle will point down to the horizon. Look to the right side of stars Alkaid and Mizar at the end of the handle, and you’ll find Lemmon just to the lower-right of the star Chara in the simple two-star constellation of Canes Venatici. From New York, it will stand about 19 degrees high — approximately the span of your outstretched hand — at 5:36 a.m. EDT, as Venus rises due east, and climb higher as dawn approaches.
After sunset, look for Comet Lemmon just below the curved handle of the Big Dipper. It will be between the two stars Chara and Cor Caroli in Canes Venatici, with the Black Eye Galaxy (M94) just above. Its height above the horizon varies by location, but from New York it will appear about 10 degrees above the northwest horizon at 7:43 p.m. EDT — roughly the width of four fingers held at arm’s length — and will gradually sink as twilight deepens.
How To Find Comet Swan
Distance from the sun: 83.8 million miles (134.9 million kilometers)
Distance from Earth: 25.6 million miles (41.2 million kilometers)
Blueish-green Comet SWAN is currently in the constellation Serpens, and will be visible in binoculars on Wednesday, Oct. 15, low in the southwest after sunset. The comet will be just to the upper-right of Sabik, a bright star in the constellation Ophiuchus, and directly above Antares in Scorpius. It will be in front of the Milky Way, so expect dense starfields to be visible behind the comet in binoculars. Its altitude varies by location, but at 7:43 p.m. EDT from New York, it will appear about 22 degrees high— roughly the distance between your little finger and forefinger held apart at arm’s length — and will gradually sink toward the horizon as the twilight fades.
Check my feed every day this month for a daily “comet tracker” with finder charts and tips for viewing Comet Lemmon from mid-northern latitudes.
