ESA's Euclid space telescope has found a previously unknown comet, designated C/2026 S1 (Euclid). Mikko Pöntinen, a Ph.D. student at the University of Helsinki, spotted it in images taken September 16-24, 2026, using software built to flag moving objects. The Minor Planet Center confirmed it as a new comet on October 8.
The comet is about 1.3 billion km from Earth, roughly between the orbits of Jupiter and Saturn, and well above the plane of the planets. It is on a long-period orbit of thousands of years, and a fuzzy cloud around it suggests it is shedding dust and gas. ESA says it is not a suitable target for its Comet Interceptor mission.
The find was a surprise: Euclid is built to map distant galaxies and study dark energy, avoids the dusty planetary plane, and usually images each patch of sky only once. It suggests the telescope can catch comets while they are still far from the Sun.