The new data release, comprising nearly 13 months of observations, marks the first major data release since the space telescope's launch in July 2023. It provides the scientific community with the puzzle pieces needed to begin constructing a detailed 3D map of the cosmos, essential for studying dark energy, dark matter, and the cosmic web.
The data is accompanied by spectra and images, including large sky mosaics. ESA's Director of Science, Professor Carole Mundell, stated: “This is much more than pretty pictures; today we mark a scientific milestone in our study of the cosmos.” She added that this publication represents “the largest survey of its kind ever undertaken from space, laying the groundwork for future discoveries in a new regime for astronomy and demonstrating the excellence of European technology and science, and international collaboration”.
Francisco Castander, a researcher at the Institute of Space Sciences (ICE-CSIC) and the Catalan Institute of Space Studies (IEEC), and a member of the Euclid consortium, highlighted the extraordinary quality and scale of the dataset, which will enable a wide range of studies and facilitate discoveries by researchers worldwide. “This release, which only includes data from the first year of the mission, is just the beginning,” he noted.
DR1-Foundation is the first substantial release, totaling 1.7 million GB of data, including over 900 million galaxies, nearly 15,000 strong gravitational lens candidates, over 60 million quasar candidates, spectra of over 160 million sources, and results from the Euclid Wide Survey covering 1900 square degrees of the sky. This data will form the basis for future research into the large-scale structure of the universe. The full DR1 release is scheduled for mid-2027.
Euclid, operating above Earth's atmosphere, can conduct deep and wide-ranging sky surveys. This release presents a far greater number of cosmic objects than any previous survey. The strong gravitational lenses detected by Euclid, formed when light from distant galaxies is significantly distorted by a foreground galaxy, constitute the largest catalog compiled to date. Natalie Lines, a researcher at the University of Portsmouth (UK), stated: “More than ten years ago, we predicted that Euclid would revolutionize the field of strong gravitational lens discovery. That day has finally arrived.”
The mission, launched in 2023, is imaging billions of galaxies across the universe and measuring the distances of millions of them. The current dataset covers about 14% of the total sky area Euclid will explore. The first complete data release (DR1), expected in mid-2027, will build upon today's release, adding weak gravitational lensing observations and calculations on how galaxies and galaxy clusters integrate into the cosmic web.
Spanish contributions to Euclid have been significant, including the participation of the Institute of Space Sciences (ICE-CSIC), the Institute of High Energy Physics (IFAE), and the Catalan Institute of Space Studies (IEEC) in the design and construction of instruments. The Polytechnic University of Cartagena (UPCT), in collaboration with the Canary Islands Institute of Astrophysics (IAC), was responsible for the control electronics of the NISP instrument. The mission's Scientific Data Center in Spain is the Scientific Information Port (PIC).
