Visiting comet formed in Universe’s infancy

An unusual comet that shot through the Solar System last year — and tempted some to dabble in the idea that it was an alien spaceship — could have formed as long as 12 billion years ago. From the chemical composition of the comet, 3I/ATLAS, researchers estimate that it formed relatively early in the history of the Universe, after an intense period of star formation. Gathering data on more interstellar objects — those that aren’t tied to an orbit and can ‘wander’ the galaxy — could “totally revolutionise what we know about the field of interstellar comets, but also star and planet formation in general”, says planetary scientist Darryl Seligman.