Astronomers have released a fresh update on Comet 3I/ATLAS, the newly identified interstellar object currently passing through the solar system. Observations as of December 13, 2025, show the comet emitting an unusual green glow, a signature commonly linked to excited carbon compounds interacting with solar radiation. Scientists have also obtained the first X-ray observations of the object, offering rare insight into how material from an interstellar comet reacts with the solar wind.
Researchers say Comet 3I/ATLAS is only the third known interstellar visitor detected after ‘Oumuamua and 2I/Borisov, making it scientifically significant. Ongoing observations aim to refine its trajectory, study its composition, and determine how long it will remain visible before exiting the solar system. Astronomers worldwide are coordinating follow-up studies to better understand what this object reveals about planetary systems beyond our own.