According to NASA, Comet Lemmon will be closest to Earth around October 21, 2025, passing at a distance of about 0.60 astronomical units, or au (1 au is the distance between Earth and the sun). The comet is then predicted to reach perihelion—the point at which it is closest to the sun—on November 8. Around the time the comet reaches perihelion, it will likely reach its maximum brightness, and may be visible to the naked eye if conditions are favorable in dark skies.