A telescope built to map galaxies just found a comet that won't return for 345,000 years

The Euclid space telescope was launched to chart the distant universe — nobody asked it to find comets. But software written by University of Helsinki PhD student Mikko Pöntinen, designed to clean up Euclid's images, kept flagging a faint streak. It was a new comet, C/2026 S1 (Euclid), spotted about 1.3 billion kilometres away and confirmed by the Minor Planet Center on October 8 — the telescope's first comet discovery, announced by the European Space Agency on October 19. The visitor comes from the Oort Cloud, the shell of icy bodies at the solar system's edge, and after this pass it will travel out to 9,786 times the Earth-Sun distance and not return for roughly 345,000 years. A by-product of a student's careful code: the universe, noticed in passing.