Comet C/2025 A6 (Lemmon)

D.C. Fuls discovered comet C/2025 A6 (Lemmon) (A6) on January 3, 2025 in Mount Lemmon CCD survey images.

It was not predicted to become a very bright comet, but it defied the predictions and became quite prominent—even visible to the naked eye—in its journey around the sun. It was closest to Earth (within 56 million miles) on October 21, 2025, when I was fortunate enough to be able to photograph A6 with one of my telescopes in Santa Fe as it was passing through the Boötes constellation. It is not expected to return to the inner solar system until the year 3195.

Not only was it a rare opportunity to photograph this celestial body, but there was also another prominent comet in the sky at the same time that I was able to photograph on the same night: Comet C/2025 R2 (SWAN).