Overview

• Swan (C/2025 R2) is expected to reach maximum brightness around October 19–20 as it passes about 30 million kilometers from Earth, with visibility likely to the naked eye for experienced observers or by binoculars.
• Lemmon (C/2025 A6) makes its closest approach near October 21 at roughly 90 million kilometers and is forecast to be brightest late in the month, with the best viewing expected October 28–31.
• As of this week, Lemmon’s apparent magnitude is about 5.5, so a dark site and at least binoculars are recommended unless it brightens as predicted.
• Where to look: Swan appears low in the southwest from mid‑October, then climbs but fades into early November; Lemmon is already high before dawn, also trackable in the evening as it moves rapidly through constellations including Ursa Major.
• Lemmon was discovered in January 2025 by the Mount Lemmon Survey, while Swan was only spotted in September after approaching from near the Sun; experts note such sunward objects are hard to detect and say dedicated space telescopes are planned.