Mark your calendars for this newly discovered comet's closest approach
Heads up, skywatchers! A newly discovered comet, C/2025 A6 (Lemmon), will make its closest approach to Earth on October 20, 2025, flying by at about 90 million km away.
Discovered earlier this year by the Mount Lemmon Survey team, it'll also reach its nearest point to the Sun in November.
When and where to spot the comet
Throughout October, Comet Lemmon will travel through constellations like Leo Minor and Ursa Major.
Early in the month, you can try spotting it before dawn near the star Tania Australis; after mid-October, look for it low in the northwest sky just after sunset.
How to view it?
The comet should glow with a greenish coma and a faint bluish tail—think of a soft cloud with a brighter center.
If brightness predictions hold (+4 to +5 magnitude), you might catch it with your naked eye; if not, binoculars or a small telescope will help.
For your best chance: find a dark spot with an open view of the western horizon at dusk later in October.