Euclid Releases Its Largest 3D Map Yet, With Over a Billion Objects Across 9,500 Full Moons of Sky
The first major data release since the dark-universe telescope's 2023 launch holds 15,000 strong-lensing candidates and spectra from more than 160 million sources.
The Euclid Consortium and the European Space Agency have released the first major batch of data from the Euclid space telescope, laying the foundation for what will become the largest 3D map of the cosmos ever made. The release, called DR1 Foundation, captures light from more than a billion objects across an area of sky equal to 9,500 full moons.
DR1 Foundation contains about 13 months of observations and is the first major release of mission data since Euclid launched in mid-2023. It gives scientists the raw material to start building a detailed three-dimensional picture of the universe, crucial for studying dark energy, dark matter and the cosmic web of galaxies and clusters. Spectra and large sky mosaics accompany the data. "These are far more than beautiful pictures; today marks a scientific milestone in our study of the cosmos," said ESA's director of science, Carole Mundell.
Analysis of about 10,000 science images from the release has already turned up large numbers of objects: around 15,000 strong gravitational lensing candidates, more than 60 million quasar candidates, which are the brilliant cores of distant galaxies, and spectra from more than 160 million sources. The Euclid Wide Survey results cover 1,900 square degrees, roughly 14% of the sky area planned for the six-year mission. Among the showcase targets is Abell 3128, a cluster of hundreds of galaxies about 800 million light-years away.
Valeria Pettorino, Euclid project scientist at ESA, said the release marks a change in scale. Previous releases included 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," she said. "This unlocks groundbreaking science."
The images come from two instruments: VIS, a 600-megapixel camera for visible light, and NISP, a near-infrared spectrometer and photometer. The Max Planck Institute for Astronomy in Heidelberg and the Max Planck Institute for Extraterrestrial Physics in Garching contributed key optical components. Raw data must be corrected for instrumental effects and converted into physical quantities, a calibration job coordinated mainly by MPIA scientists Mischa Schirmer and Kerry Paterson, and data are processed at sites including the German Science Data Center.
More than 300 research institutions in Germany and abroad analyze the data, and over 2,500 researchers use it. Frank Grupp of Ludwig Maximilian University of Munich, the German Euclid project manager and optical architect of the mission, said more than 15 years of preparation before launch and over three years in orbit are now paying off.
Jochen Weller of LMU said the data bring physicists a step closer to understanding why the expansion of the universe is accelerating, a mystery that has challenged physics for nearly 30 years. Euclid's map of where matter sits and how it has clustered over cosmic time is one of the main tools for testing competing explanations, whether a form of dark energy, a modification of gravity, or something else entirely.
