Two green-hued comets, C/2025 A6 (Lemmon) and C/2025 R2 (SWAN), are visible in the Northern Hemisphere this fall, offering a rare chance to spot both in the same month.

Comet Lemmon may become visible to the naked eye around Oct. 21 when it is closest to Earth, while Comet SWAN is best seen with binoculars or a small telescope about 90 minutes after sunset, peaking near Oct. 20.

Lemmon will first appear near the Big Dipper in the pre-dawn sky before shifting to the evening sky later in October.

The green glow of both comets comes from carbon in the gas surrounding their nuclei, NBC News has reported.

Additionally, interstellar comet 3I/ATLAS is also passing through the inner solar system this month, making its closest approach to the sun around Oct. 30.