Two Comets to Illuminate October Skies
Comets C/2025 R2 (SWAN) and C/2025 A6 (Lemmon) will make their closest approaches to Earth in October, offering skywatchers a rare opportunity to observe both celestial bodies.
In October 2025, skywatchers will have the rare opportunity to observe two comets, C/2025 R2 (SWAN) and C/2025 A6 (Lemmon), as they make their closest approaches to Earth. Comet SWAN, discovered on September 12, 2025, is a long-period comet with an orbital period of approximately 22,554 years. It will pass within 0.27 astronomical units (AU) of Earth on October 21 and is expected to reach a brightness of magnitude 4, potentially visible to the naked eye under dark skies.
Comet Lemmon, first observed on January 3, 2025, has an orbital period of about 1,350 years. It will come within 0.60 AU of Earth on October 21 and may also achieve a brightness of magnitude 4. Both comets are anticipated to be most visible between October 20 and 23, coinciding with the peak of the Orionid meteor shower on October 21, which could produce up to 20 meteors per hour.
Observers in the Northern Hemisphere are advised to use binoculars or small telescopes for optimal viewing. The Virtual Telescope Project will host an online observation session on October 20, 2025, starting at 17:30 UTC, to showcase both comets during their closest approach to Earth.