ESA’s Euclid Space Telescope Discovers Its First Comet
The ESA's Euclid space telescope has unexpectedly discovered its first comet, designated C/2026 S1 (Euclid). The discovery was made by a Ph.D. student using data from the telescope, which is primarily designed to observe distant galaxies.
Why it matters
This discovery demonstrates the versatility of the Euclid mission and provides a new test case for future astronomical coordination.
Officially named C/2026 S1 (Euclid), the comet turned up in images Euclid captured between September 16 and 24, 2026.
This Euclid shows the comet C/2026 S1 (Euclid). Image credit: ESA / Euclid / Euclid Consortium / NASA / Pöntinen et al .
C/2026 S1 (Euclid) is currently about 1.3 billion km (800 million miles) from Earth, roughly the distance between the orbits of Jupiter and Saturn.
The comet sits well above the plane of the planets and travels an orbit that will take thousands of years to complete. Its exact period will be refined as more observations come in.
The discovery was made by Mikko Pöntinen, a Ph.D. student at the University of Helsinki, working with the Solar System Objects Science Working Group of the Euclid Consortium.
“I was excited to see my software flag a ‘streak’ smeared across several images — the result of a fast-moving object,” Pöntinen said.
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