After its first approach to Earth, I imaged comet C/2025 K1 (ATLAS) on August 21, 2025, when it was near the star 9 Herculis. In this image it shines at about magnitude 12.5, showing a greenish coma just over 2 arcminutes wide with moderate central condensation. The tail extends roughly 20 arcminutes. On its way to perihelion, which it will reach on October 8 at only 0.33 AU from the Sun – inside Mercury’s orbit –, the comet faces a high risk of disintegration. If it survives, it could become observable again on its return toward Earth, in the morning sky of the Northern Hemisphere, reaching a brightness near magnitude 8 and perhaps visible with binoculars.

Daten zum Bild