Comet C/2026 S1 (Euclid) streaks across the sky (annotated)

The European Space Agency's Euclid space telescope has discovered its first previously unknown comet: C/2026 S1 (Euclid).

In this image sequence it moves against background stars and galaxies in three of Euclid’s VIS camera exposures captured during the Euclid Deep Field North survey.

The images were taken at 00:41:07, 00:58:53 and 01:16:39 UTC on 17 September 2026. Each image is a 560.52 second exposure, so the comet appears like a streak because it moves across the sky during the long exposure. A fuzzy atmosphere, known as a ‘coma’ in cometary terms, is seen around the object.

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[Image description: A black-and-white telescopic view of deep space shows a faint comet, labelled “C/2026 S1 (Euclid),” moving slowly against a background of stars. An arrow points to the comet’s bright central core and short tail. A timestamp updates as the animation progresses, highlighting the comet’s motion over time. Orientation markers and a scale bar provide celestial directions and distance.]