When an interstellar comet tears through our Solar System at 250,000 kilometres per hour, pinning down its exact trajectory becomes a race against time. ESA astronomers achieved something unprecedented in October 2025, using observations from the ExoMars Trace Gas Orbiter to improve predictions of comet 3I/ATLAS's path by a factor of ten. By triangulating data from Mars with Earth based observations, scientists demonstrated a powerful technique for tracking fast moving objects that could prove invaluable for planetary defence, even though this particular visitor poses no threat to our planet.