Comets C/2025 K1 ATLAS, C/2025 R2 SWAN spotted side by side
In a cosmic treat this September, skywatchers over Reunion Island caught two comets—C/2025 K1 ATLAS and C/2025 R2 SWAN—gliding side by side.
Despite having totally different origins, both showed off bright comas and glowing tails, making for a rare double feature in the night sky.
More about the 2 comets
ATLAS is an interstellar visitor discovered in May 2025. It's zooming through our solar system on a one-time trip, coming closest to the Sun on October 8 and passing Earth at 0.4 AU on November 25.
SWAN, spotted in September by SOHO's SWAN instrument, is a long-period comet with a greenish glow that will swing by Earth at its closest (0.26 AU) on October 20.
How to spot these comets?
If you're in the Southern Hemisphere with binoculars handy, look near Mars to catch SWAN's green coma until late October. ATLAS will stick around until November.
This rare pairing lets us see an interstellar object alongside a classic comet—a cool reminder of how lively our corner of space can be!