Comets Lemmon and SWAN Illuminate October Skies
Two comets, C/2025 A6 (Lemmon) and C/2025 R2 (SWAN), are making their closest approaches to Earth this month, offering skywatchers a rare opportunity for observation.
Two comets, C/2025 A6 (Lemmon) and C/2025 R2 (SWAN), are currently visible in the night sky, providing a unique spectacle for stargazers. Comet Lemmon reached its closest approach to Earth on October 21, while Comet SWAN did so on October 20. Both comets are best observed with binoculars or small telescopes, though Lemmon may be visible to the naked eye under dark skies.
Comet Lemmon can be found in the northwest sky near the Big Dipper and the star Arcturus, while Comet SWAN appears lower in the southwest, between Altair and the horizon, near the Summer Triangle. Optimal viewing time for both comets is about 90 minutes after sunset.
Both comets exhibit a greenish hue due to the emission of gas, though they may appear as gray fuzzy patches to the naked eye. They are expected to remain visible with binoculars through the end of October.
These comets originate from the distant Oort Cloud at the edge of the solar system. Comet Lemmon follows a 1,350-year orbit, while Comet SWAN has a 20,000-year orbit.
Observers are advised to find locations away from city lights to enhance visibility. The new moon on October 21 provides ideal dark-sky conditions for viewing.