The ESA's Euclid Space Telescope has discovered its first comet, a result that's not part of its primary mission. The telescope was launched at the beginning of July, 2023, and its mission is to observe about 1.5 billion galaxies out to redshift z=2, which corresponds to seeing around 10 billion years into the past. The goal is to measure the redshift of a massive amount of galaxies, to shed light on the expansion history of the Universe and the force that drives it, dark energy.

The space telescope has observed other comets, but this is the first time it's discovered one. The comet was found in multiple images captured between September 16th and 24th, 2026. For a telescope built to take deep images of distant galaxies, discovering a rapidly moving comet in the Milky Way is a surprising bonus.

The comet didn't announce its presence. The discovery relied on new software designed by Mikko Pöntinen of the University of Helsinki.…