Two Comets Offer Viewing Opportunities This Fall
Two comets, recently discovered visitors from the outer solar system, are currently visible to observers with binoculars. Comet C/2025 R2 (SWAN) and Comet C/2025 A6 (Lemmon) present opportunities for stargazers throughout October and November.
Comets are frequently enough described as “dirty snowballs,” composed of dust, ice, and rock. As a comet approaches the sun, its heat causes these volatile materials to vaporize, creating a glowing coma (a shell of gas and dust) and often a visible tail.
Comet SWAN was discovered in september by an amateur astronomer analyzing images from a solar observatory.its orbit brought it to its closest approach to the sun on September 12, 2025, and it is now moving away. SWAN will reach its closest approach to Earth on October 20th, at a distance of approximately 40 million kilometers. Currently best viewed from the Northern Hemisphere, SWAN is traversing the constellations Serpent, Shield, and Sagittarius, appearing low in the southwestern sky in October and moving towards the south in early November. Optimal viewing requires a clear southwestern horizon and is best attempted at dusk. SWAN will remain visible with binoculars until early November.
Comet Lemmon is currently brighter than SWAN and positioned higher in the sky, below the Big Dipper and moving towards the constellation bear guardian. It is expected to become even brighter in the coming days,potentially becoming visible to the naked eye from locations with dark skies. Uwe Pilz, chairman of the Association of Star Friends (VdS), notes that Lemmon is currently easier to observe in the morning sky. Lemmon will reach its closest point to Earth on October 21st, further increasing its brightness.
While binoculars are currently needed for both comets, observers are encouraged to be patient. comet SWAN will be visible until the beginning of November, and Comet Lemmon will remain observable until mid-November, disappearing at dusk.
