Euclid space telescope discovers new comet C/2026 S1

The European Space Agency’s Euclid space telescope has discovered a previously unknown comet, designated C/2026 S1 (Euclid). The object was detected in deep-sky images captured between September 16 and 24, 2026.

Although Euclid is primarily designed to map galaxies and study dark matter and dark energy, Mikko Pöntinen of the University of Helsinki identified the object using moving object detection software. The software flagged a streak across several images, which was later confirmed to have a fuzzy cloud of dust and gas, indicating cometary activity.

After finding no matches in existing astronomical catalogues, the findings were reported to the International Astronomical Union’s Minor Planet Center. Ground-based observations confirmed the discovery on October 8. The comet is currently located approximately 1.3 billion kilometres from Earth, positioned between the orbits of Jupiter and Saturn.