ESA Euclid space telescope discovers new comet C/2026 S1

The European Space Agency (ESA) Euclid space telescope has discovered a previously unknown comet, officially designated C/2026 S1 (Euclid). While the mission's primary objective is to study dark matter and dark energy by observing distant galaxies, the telescope's instruments captured the object in images taken between September 16 and 24, 2026.

Researcher Mikko Pöntinen from the University of Helsinki identified the object using software designed to detect moving objects within telescope imagery. The software flagged a blurred streak across multiple images, which detailed analysis revealed to be a diffuse cloud of dust and gas, or coma, indicating an active comet. The discovery was confirmed by the International Astronomical Union's Minor Planet Center on October 8.

Located approximately 1.3 billion kilometers from Earth, the comet is positioned in the solar system between the orbits of Jupiter and Saturn. Its trajectory travels above the planetary orbital plane and is expected to take thousands of years to complete a single orbit. This finding is notable as Euclid is not specifically designed for comet hunting, as it typically avoids areas of the sky with high solar system dust to maintain deep, stable images of distant galaxies.