Euclid opens a dataset covering more than 900 million galaxies
Euclid’s DR1-Foundation release opens 13 months of observations for scientific use, covering roughly 1,900 square degrees of sky. Images contain more than 900 million galaxies, alongside catalogues of gravitational lens and quasar candidates. Researchers also gain spectra for more than 160 million sources. Higher-level products on weak lensing and galaxy clustering are scheduled for the full release in mid-2027.
Science··Night
Thirteen months of observations become available
Euclid, the European Space Agency’s space telescope studying the dark universe, has opened its DR1-Foundation dataset. The release announced on November 12 contains 1.7 million gigabytes from 13 months of observations. Images cover more than 900 million galaxies across roughly 1,900 square degrees, about 14 percent of the planned survey area.[1], [2]
The mission launched from Florida in 2023 and aims to assemble a three-dimensional cosmic atlas by 2031. Project scientist Valeria Pettorino explained that distances add the third dimension to galaxy images. The placement of galaxies at different distances also places those galaxies at different stages in cosmic history, allowing researchers to reconstruct how the large-scale structure changed over time.[2]
Catalogues include lens and quasar candidates
The catalogues list around 15,000 strong gravitational lens candidates and more than 60 million quasar candidates, objects whose classifications still require assessment. Quasars are bright centres of distant galaxies. Spectra for over 160 million sources separate light by wavelength, providing information for investigating distances and physical properties. Raw data, processed images and catalogues are also available.[1]
Galaxies form filaments and clusters separated by emptier regions, together known as the cosmic web. Its arrangement carries information about dark matter and dark energy. Natalie Lines, a Euclid Consortium researcher at the University of Portsmouth, described gravitational lenses as a way to examine the mass inside galaxies. The bending of background light depends on foreground matter, including components invisible in the images.[2]
Full release adds higher-level products in 2027
Euclid launched in 2023 and began routine science observations on February 14, 2024. Limited releases followed in March 2025 and June 2026. The full DR1 release, planned for mid-2027, will add higher-level products including weak gravitational lensing and galaxy clustering. Those measurements serve the mission’s investigation of dark matter and the accelerating expansion of the universe. Researchers outside the mission team can also investigate these sky regions for their own projects. Spain’s Instituto de Astrofísica de Canarias contributed control electronics and start-up software for the near-infrared instrument. More than 2,000 researchers at 300 institutions participate in the science consortium. The public observations supply images, catalogues and spectra for separate investigations of the same sky regions.[1]
