ESA releases first large Euclid dataset, groundwork for largest 3D cosmos map

First large release from the mission

The European Space Agency (ESA) has published for the first time a large dataset from its Euclid space mission. The release, named 'DR1-Foundation', draws on observations gathered over 13 months and amounts to 1.7 million gigabytes. It contains more than 900 million galaxies, over 60 million quasars and 15,000 candidates for strong gravitational lenses. Spectra of more than 160 million radiation sources are also included. Taken together, the covered area amounts to about 14% of what Euclid is designed to survey during its six-year mission.

Galaxies (more than 900 million)900,000,000

Quasars (over 60 million)60,000,000

Radiation sources with spectra (more than 160 million)160,000,000

Candidates for strong gravitational lenses (15,000)15,000

Galaxies (more than 900 million)

900000000 objects

Quasars (over 60 million)

60000000 objects

Radiation sources with spectra (more than 160 million)

160000000 objects

Candidates for strong gravitational lenses (15,000)

15000 objects

Data from the article text

What the mission is after

ESA says the release lays the groundwork for the largest 3D map of the cosmos created so far. Euclid launched in summer 2023 and carries a high-resolution telescope with two instruments. The visible-light camera (VIS) records the shapes of galaxies, while the near-infrared instrument (NISP) takes spectroscopic and photometric measurements that help establish how far away galaxies are. The Max Planck Institute for Extraterrestrial Physics in Garching near Munich and the Max Planck Institute for Astronomy in Heidelberg contributed key parts of the near-infrared instrument. The mission aims to study the development of the universe over the past ten billion years, adding time as a third dimension to its map. Dark matter and dark energy together make up an extremely large share of the universe, while all other known components, including galaxies, account for only about 5%. Researchers still know little about either.

Timing and scale

ESA's science director, Carole Mundell, framed the release in terms of the agency's scientific goals.

“These are far more than pretty pictures. Today marks a scientific milestone in our exploration of the cosmos.”

The new data rest on 13 months of telescope operation. An earlier data release, published in 2025, contained images of only a few days. The observed area from the new release would fill the space of 9,500 full moons placed side by side, and it represents about 14% of the total area Euclid is meant to observe over its entire mission. Over 900 million galaxies sit within that footprint, along with an estimated 60 million possible active galactic nuclei.

What comes next

Karina Rojas, an astrophysicist from the University of Applied Sciences Northwestern Switzerland (FHNW) who takes part in the mission, told Keystone-SDA that the release is only the start.

“This is only the beginning of the story.”

Several Swiss research institutions are involved in the mission. The full 3D map will take shape over the coming years as the rest of the planned survey is completed. For now, the published data cover only a fraction of the sky that Euclid is set to capture.