--- title: "Telescope Euclid Accidentally Discovers New Comet C/2026 S1: Apparatus Built to Study Dark Energy Finds Object in Solar System" description: "European telescope Euclid accidentally discovered new comet C/2026 S1 in deep sky images. The object was confirmed by the Minor Planet Center and became the spacecraft's first independent discovery in the Solar System." date: 2026-10-21T05:16:26.421Z lang: en url: https://xab.info/en/posts/euclid-discovers-new-comet-c-2026-s1 tags: [euclid, comet, esa, solar-system, astronomy] author: "Alexander Buran" publisher: "XAB.info" --- # Telescope Euclid Accidentally Discovers New Comet C/2026 S1: Apparatus Built to Study Dark Energy Finds Object in Solar System ![Space telescope Euclid in outer space against the starry sky](https://xab.info/media/2026/10/21/euclid-otkryl-novuyu-kometu-c-2026-s1/euclid-otkryl-novuyu-kometu-c-2026-s1-1.webp) ## Key Points - Telescope Euclid made its first independent discovery in the Solar System — comet C/2026 S1 (Euclid) - The object was discovered by University of Helsinki graduate student Mikko Pöntinen using custom software on deep northern sky survey images - The IAU Minor Planet Center confirmed the discovery on October 8, 2026 - The comet moves in an unusual near-perpendicular orbit with an orbital period of thousands of years - The find creates a precedent for future ESA missions, particularly Comet Interceptor The European space telescope Euclid has made its first independent astronomical discovery within the Solar System: the spacecraft detected a previously unknown comet, which after verification received the official designation C/2026 S1 (Euclid). This was reported by RBC-Ukraine with reference to an official material from the European Space Agency (ESA). The find came as a surprise to the scientific team, since the telescope was not built to search for passing asteroids and comets, but for fundamental cosmological research, and it was precisely this "serendipitous luck" that provided scientists with a new object to study. ### An Unplanned Discovery Euclid's primary mission is to study the shape and motion of billions of galaxies up to 10 billion light-years away from Earth in order to uncover the nature of dark matter and dark energy. To avoid stray light from interplanetary dust, asteroids, and comets that interfere with sensitive deep-space images, the telescope is intentionally pointed at patches of the sky far from the plane of the Solar System. Furthermore, Euclid takes snapshots and does not return to the same areas repeatedly, making the accidental capture of a moving object against the deep sky background a rare and valuable occurrence. According to Naked Science, the images in which the comet was found were taken as part of a deep survey of the northern sky from September 16 to 24, 2026. ### How a Graduate Student Spotted the Comet in the Images The atypical object was first noticed by Mikko Pöntinen, a graduate student at the University of Helsinki, using software he developed: algorithms detected a blurred trail from a fast-moving object on the images. Subsequent analysis confirmed the presence around it of a foggy cloud of dust and gas—a coma, which is characteristic of active comets. After cross-referencing catalogs and confirmation by the Minor Planet Center (MPC) of the International Astronomical Union on October 8, 2026, the object was officially registered as C/2026 S1 (Euclid). The algorithms captured the comet in five different image sets—totaling 16 exposures in Euclid's deep northern survey field. ### Unusual Orbit and Comet Parameters At the time of discovery, the comet was located at a distance of about 1.3 billion kilometers from Earth, which roughly corresponds to the distance from the Sun to the region between the orbits of Jupiter and Saturn. The unusual motion geometry is noteworthy: the comet does not travel in the plane of the planets, but effectively "perpendicularly" upward from the Sun, describing an arc over the Solar System. The object's full orbital period around the Sun is estimated in thousands of years, pointing to its origin from the distant regions of the planetary system. ### A Precedent for Future ESA Missions Comets are icy and dusty remnants from the era of the Solar System's formation 4.6 billion years ago. Studying their composition helps scientists understand what materials planets formed from and where water and primordial organic building blocks on Earth came from. Detecting a comet at such an early stage and at a significant distance from the Sun proves that Euclid is capable of searching for new objects in the deep sky. This creates an important precedent for cooperation with future ESA research missions, in particular the Comet Interceptor spacecraft, which plans to intercept pristine comets during their first approach to the center of the planetary system. ## Fact-Check & Sources - [Случайная удача: телескоп Euclid открыл новую комету в Солнечной системе](https://www.rbc.ua/ukr/news/vipadkoviy-uspih-teleskop-euclid-vidkriv-1792507172.html) - Primary source: discovery of comet C/2026 S1 (Euclid), ESA's role, Pöntinen's detection method, MPC confirmation on October 8, orbital parameters and distance ~1.3 billion km, connection to Comet Interceptor. - [Новая комета C/2026 S1 стала первой, обнаруженной телескопом Euclid](https://naked-science.ru/article/astronomy/kometa-c-2026-s1) - Complements with the date of the deep northern sky survey (September 16–24, 2026), MPC confirmation on October 8, and the fact that Euclid does not return to the same areas of the sky. ## FAQ ### What is C/2026 S1 (Euclid)? It is a previously unknown comet discovered in images from the European telescope Euclid and officially registered by the IAU Minor Planet Center on October 8, 2026. It became the spacecraft's first independent astronomical discovery in the Solar System. ### How exactly was the comet discovered? University of Helsinki graduate student Mikko Pöntinen used custom-developed software to notice a blurred trail of a fast-moving object in deep northern survey field images; further analysis confirmed the presence of a dust and gas coma. ### What was telescope Euclid built for? The mission's main goal is to study the shape and motion of billions of galaxies up to 10 billion light-years away to uncover the nature of dark matter and dark energy, rather than searching for comets and asteroids. ### What is unusual about comet C/2026 S1's orbit? The comet does not move in the planetary plane, but effectively perpendicular upward from the Sun, describing an arc over the Solar System, and its full orbital period around the Sun is measured in thousands of years.