Rare Double Comet Display Lights Up Northern Skies
Skywatchers in the Northern Hemisphere have a rare โคchance this week โฃto witness two green comets together. comet Lemmon will make its closest approach to Earth around Tuesday, while Comet SWAN had its flyby on Monday, though it’s already โขbeginning to fade as it moves โขaway from the sun.
The simultaneous appearance of โtwo comets visibleโค without specialized equipment is uncommon, but not unheard of, according to โคexperts. โboth comets originate from the outer solar system-potentially the โขOort cloud,far beyond Pluto-and offer a glimpse into the solar system’s ancient past.
To spot the celestial duo, observers shouldโฃ look to the northern sky just after sunset. Comet Lemmon will be low on the horizon, while Comet SWAN will appear to theโ southwest, alsoโ near the horizon. Binoculars may enhanceโ the view through the end of the month, though their brightness remainsโข uncertain.
These “cosmic โsnowballs” are frozen remnants from the formation of the โขsolar system billions of years ago. As thay approach the sun, they heat up and release gases, creating their distinctive streaming tails and a characteristic green โฃhue.
comet Lemmon, officially designatedโฃ C/2025 A6, was discovered in January by a telescope searching for near-Earth asteroids. Comet SWAN, or C/2025โ R2, was spotted in September by an amateur astronomer using dataโค from a โฃNASA and European โSpace Agency spacecraft. Despiteโ their color, both comets will likely appear as gray, โฃfuzzy patches to theโฃ naked eye.
“Spotting two comets simultaneously without special equipment is rare, but not unprecedented,” said Carson Fuls, director of โthe University of Arizona sky survey that discovered Comet Lemmon.
Recent notable comet flybys include the greenโฃ comet that โขfragmented near the sun earlier thisโ year, Tsuchinshan-Atlas in 2024, Neowise in 2020, and Hale-bopp and Hyakutake in the 1990s.
