Astronomers thought they had the trajectory of the latest interstellar visitor figured out, but the object had other plans. For weeks, 3I/ATLAS slipped out of view from ground-based telescopes, obscured by the glare of the Sun. When it finally re-emerged, it was not the same object that had vanished into the solar glare.
Instead of dimming as it drifted away, the comet suddenly lit up with a brilliant, surprising glow. But the real shock came from its appearance: it had turned a vivid, striking blue. This completely bucked the standard models for how cometary gas and dust are supposed to act.
