Comet Lemmon (C/2025 A6) nears November perihelion, may shine bright enough for naked-eye viewing

Naked-eye comets are rare, appearing roughly once or twice every decade. Unlike the sharp pinpoint of a star, Comet Lemmon will appear as a diffuse, ghostly glow with a faint tail. In 1974, Kenneth Weaver, assistant editor of National Geographic, described a similar comet, Kohoutek, as a “ghostly swath” with a softly glowing core, like a paintbrush stroke of whitewash across the night sky, observed from the dark skies of Kitt Peak National Observatory near Tucson, Arizona.

Today, light pollution makes such pristine viewing conditions harder to find. Urban skyglow obscures stars and comets for most people in the United States. 

To see Comet Lemmon clearly, seek a dark-sky location far from city lights, where the Milky Way is visible overhead. In hazy or light-polluted areas, the comet may appear faint or not at all. Comet Lemmon is will be best observed in the morning sky, requiring early risers to look for it about 90 minutes before sunrise.

With the full moon on October 6 making faint objects hard to see, viewing conditions will improve as the moon wanes post-October 13. The comet will then transition to evening viewing after October 16, becoming especially prominent between October 22 and 28, when it will be low in the west-northwest sky.