One of the largest cosmic data releases ever assembled arrived on November 12, 2026. The European Space Agency’s Euclid mission released its DR1-Foundation dataset: approximately 1.7 petabytes of survey material spanning about 13 months of observations, with light from more than 900 million galaxies.
What astronomers received
According to the Euclid Consortium and partner researchers, the release includes imaging and spectra covering roughly 1,900 square degrees of sky, more than 60 million quasar candidates and around 15,000 strong gravitational-lens candidates. Lensing occurs when the gravity of foreground matter bends the light of a more distant source, sometimes creating arcs and multiple images.
Why lenses are more than pretty pictures
A distorted galaxy can carry information about the gravity and mass of another galaxy between us and the source. That includes mass not readily visible in stars or gas. With enough examples, researchers hope to examine the distribution of dark matter and eventually test explanations for the universe’s expansion.
What hasn’t been established yet
This is a foundation data release, not a final answer to dark energy. The Euclid team expects additional measurements—including weak-lensing and galaxy-distribution products—in a fuller release in 2027. The immense catalog offers unprecedented opportunity but also demands careful calibration, validation and selection of candidates before statistics become cosmological claims.
Featured image is genuine astrophotography of the night sky, not a mosaic from Euclid’s November 12 data release.
