Interstellar Comet 3I/ATLAS Stuns Scientists with Surprising Bright Outburst and Ancient Origins
Comet 3I/ATLAS, discovered July 1, 2025 by the ATLAS survey in Chile, is only the third known interstellar object to enter the solar system. The comet brightened rapidly as it passed the Sun on October 29, baffling astronomers and revealing strong outgassing of water vapor and carbon dioxide. It will not approach closer than 1.8 AU from Earth. Analyses suggest 3I/ATLAS may be nearly 10 billion years old.