Science and wonder in Euclid’s colorful Universe

Jean-Charles Cuillandre (CEA AIM, OSU Paris Saclay)

ESA’s Euclid journey from raw data to global awe began with its Early Release Observations (ERO) program, marking a series of pivotal media moments that showcased the mission’s capabilities and long-term vision. In November 2023, the first release unveiled breathtaking color images from Euclid’s twin panoramic cameras, signaling to the world that the telescope was fully operational. The second release in May 2024 highlighted Euclid’s ability to deliver novel science through detailed observations of the nearby universe. In October 2024, the unveiling of the first segment of Euclid’s cosmic atlas, a 208-gigapixel mosaic spanning 132 square degrees of the Southern Sky, brought the mission’s six-year survey plan into focus. Most recently, in March 2025, Euclid released its first batch of survey data and science results by the Euclid Consortium with a preview of its three deep fields capturing 26 million galaxies. This presentation explores the technical and creative processes behind these milestones, with a focus on the making of Euclid’s color images. From detecting ultra-faint low surface brightness features like galactic cirrus clouds and stellar streams to leveraging deep learning techniques for refining data at all scales, each image release showcased Euclid’s scientific power while captivating a global audience.