When 3I/ATLAS was first spotted, astronomers assumed it was another interstellar comet. After all, we had seen this before with ‘Oumuamua and Borisov—strange objects from other star systems swinging past our Sun and vanishing into the void. But 3I/ATLAS immediately set itself apart. It wasn’t just its trajectory or its velocity that raised eyebrows—it was how it behaved.
Unlike typical comets, which develop a visible coma of water vapour and dust when they approach the Sun, 3I/ATLAS stubbornly refused to follow the script. No coma. No tail. No water. Instead, it emitted only carbon dioxide—and in large quantities—while remaining eerily silent in all other spectrographic readings.