It was an astronomical stroke of luck: a once-in-a-lifetime encounter between an interplanetary tourist and a spaceship on a decades-long journey. The mysterious interstellar comet, 3I/ATLAS, was screaming through our Solar System when the European Space Agency's (ESA) Jupiter Icy Moons Explorer (Juice) happened to be in the right place at the right time.
What followed was an unexpected, high-stakes observation campaign that has given astronomers the first close-up peek at a highly active visitor from beyond our stellar neighbourhood.
