The European Space Agency on Thursday issued the first major data release from its Euclid space telescope, a trove it says captures the light of more than a billion objects and covers an area of sky as large as 9,500 full moons, according to ESA's announcement.
The release, named DR1-Foundation, comprises about 13 months of observations and is the first major batch of mission data since Euclid launched in mid-2023. "These are far more than beautiful pictures; today marks a scientific milestone in our study of the cosmos," said Carole Mundell, ESA's director of science. "This major Euclid data release represents the largest space-based survey of its kind, laying the foundation of future discovery." Valeria Pettorino, ESA's Euclid project scientist, said earlier releases covered only a few days of observations over about 60 square degrees. "We're now releasing more than a year of data covering a significantly larger area. This unlocks ground-breaking science."
What is in the catalog
Live Science, describing the same Thursday release, reported observations of more than 900 million galaxies and 60 million black-hole-powered light sources in the early universe, plus more than 15,000 strong gravitational-lensing candidates. Those counts were not itemized in the same way in the ESA page reviewed for this story, which instead said the release captures light from more than a billion objects and includes the largest strong-lens catalog ever assembled, bigger than all previous catalogs combined. This account reports both descriptions and does not collapse them into a single number.
ESA said the data include spectra — "rainbows" of light — for 160 million sources. Scientists will use those spectra, including hydrogen-alpha signatures, to measure distances to galaxies and map the 3D structure of the cosmic web, the main goal of Euclid's spectroscopy. The mission is designed to probe dark energy, dark matter and the large-scale structure of the universe from above Earth's atmosphere, which blurs and dims ground-based images.
The catalog is now available to scientists as a foundation for the 3D map ESA says Euclid is built to produce. The agency did not, in the materials reviewed here, set a date for a completed all-sky map.