Comet C/2025 A6 (Lemmon), discovered in January by the Mount Lemmon Observatory in Arizona, reached its peak brightness on October 21, about 90 million kilometers from Earth. It is visible to the naked eye in dark areas across the US until early November, before moving away from the Sun. The event coincides with the Orionid meteor shower, creating a dual celestial spectacle.
Originating from the Kuiper Belt, the comet reflects sunlight off its coma, forming a greenish tail visible with binoculars or the naked eye.
- Where to observe: Rural areas with minimal light pollution are ideal.
- Best time: After sunset, starting October 27, near Mercury, Mars, and Antares.
- Equipment: Binoculars or telescopes enhance the tail; it appears as a faint, fuzzy point without gear.
Optimal viewing conditions
Clear skies and dark locations are crucial for spotting the comet’s greenish glow.
Urban light pollution can obscure the view, so remote areas are recommended.
Comet’s path and features
Lemmon follows a highly elliptical orbit, returning every 1,300 years.
Its brightness peaks as it nears the Sun, releasing gases like cyanogen and diatomic carbon.
The solar wind shapes its tail, always pointing away from the Sun.
On November 8, at perihelion, its closest point to the Sun, brightness may intensify.
Orionid meteor shower
The Orionids, caused by debris from Halley’s Comet, peak this week with dozens of meteors per hour.
These “shooting stars” are best seen in dark, clear skies.
Eyes need 20-30 minutes to adjust to darkness for optimal viewing.
Other comets in 2025
The C/2024 G3 (ATLAS) was visible in January, peaking early in the year.
The 24P/Schaumasse will appear from December 2025 to January 2026, requiring telescopes.
The 210P/Christensen, visible until December, peaks in November.
Tips for US observers
Astronomers suggest:
- Choose spots far from city lights.
- Use astronomy apps to locate the comet.
- Bring binoculars for a clearer view of the tail.
- Observe between sunset and midnight, starting October 27.
Upcoming celestial events
Lemmon won’t return for 1,300 years, making this a rare event. The Orionids end on November 7, with comets like Schaumasse appearing in December.
