Overview
- C/2025 A6 (Lemmon) is near its brightest at about magnitude 4.4, making it easy to spot with binoculars and potentially visible to the naked eye from very dark sites.
- The best viewing is in the evening around 21:00 local time, about 42 degrees above the western horizon roughly halfway between the Big Dipper and the bright star Arcturus.
- The comet passed its closest point to Earth on October 21 at roughly 90 million kilometers, and astronomers report no known impact risk.
- Perihelion occurs on November 8, with models indicating its orbital period will decrease from about 1,350 years to roughly 1,150 years.
- Discovered on January 3, 2025 by the Mount Lemmon Survey, the greenish comet is an icy body from the outer Solar System whose warming near the Sun produces its coma and tail.