Comets on the Horizon: Lemmon and SWAN Illuminate November Skies
The cosmos is offering us a rare double spectacle this month: two relatively bright comets are approaching Earth at the same time and will illuminate november skies.
They are the newly discovered C/2025 A6 (Lemmon) and C/2025 R2 (SWAN), both visible over the next few nights under ideal conditions — especially from dark-sky locations like La Palma, a paradise for astronomy and stargazing.
Two Icy Travelers Meet in Time
It’s surprising — and quite uncommon — that two comets with such distinct orbits and origins are passing close to Earth almost simultaneously.
Their journeys through the Solar System are immense: Lemmon completes one orbit around the Sun every 1,400 years, while SWAN takes more than 20,000 years.
A cosmic coincidence that happens only once in many generations.
☄️ C/2025 A6 (Lemmon): The Comet You Might See with the Naked Eye
Discovered in early 2025 at the Mount Lemmon Observatory in Arizona, this comet promises to become one of the most beautiful sights of the autumn sky.
According to forecasts, it may be visible to the naked eye as a faint, slightly diffuse star, and even more clearly through binoculars or a small telescope.
Through an optical instrument, Lemmon will appear as a small, nebulous patch with a bright core and a short tail pointing away from the Sun. For astrophotography enthusiasts, this is a unique opportunity: use a camera on a tripod — ideally with tracking — and bright lenses of 200 mm or longer.
Lemmon will be visible shortly after sunset, between 30 and 60 minutes after dusk, low above the northwest to west horizon. Its position will change slightly from night to night but will remain low in the sky. You can use the bright star Arcturus as a reference point — the comet will appear just above it.
C/2025 R2 (SWAN): A Subtle but Photogenic Visitor
The comet SWAN, also discovered this year, will be somewhat fainter than Lemmon, though still perfectly observable with binoculars or amateur telescopes.
It is currently crossing the Milky Way above the constellation Sagittarius, making it a fantastic target for long-exposure astrophotography.
Although it will not be visible to the naked eye, its location among the bright star clouds of the galactic center makes it ideal for photographers. In images, it will appear as a small bluish-green haze with a delicate, diffuse tail pointing away from the Sun.
Where and How to See Them from La Palma
La Palma, a Starlight Reserve and UNESCO Biosphere Reserve, offers perfect conditions to follow both comets. You don’t need to go up to the Roque de los Muchachos Observatory; just visit one of the island’s many astronomical viewpoints, especially those with a clear view to the west.
Both comets will remain visible for the next few weeks, though their maximum brightness will last only a few days.
Spotting them from La Palma will be a privilege for anyone passionate about the night sky and astrophotography. We’ll do our best to show them to you during one of our guided astronomy tours.