A PhD student in Helsinki spotted a blurry streak — it was a brand-new comet

Europe's Euclid telescope was built to photograph galaxies billions of light-years away, not to find comets. But a PhD student in Helsinki wrote a small programme to scan its images for moving objects, and one blurry streak turned out to be something nobody had ever seen: a comet, now named C/2026 S1 (Euclid). It sits about 1.3 billion kilometres (about 808 million miles) from Earth, between the orbits of Jupiter and Saturn, and it travels almost straight up over the plane of the planets — which is exactly why a galaxy telescope, which avoids that plane, could catch it. One lap of the Sun takes it thousands of years. For ESA, the lucky find doubled as a first rehearsal for its future Comet Interceptor mission, which will wait in space for a fresh comet to visit.