Euclid mission releases data on 26 million galaxies

On March 19, 2025, the European Space Agency's Euclid mission shared its first batch of survey data. This data highlights a preview of its deep fields, showcasing hundreds of thousands of galaxies in various shapes and sizes. It offers a look at how these galaxies are organized in the cosmic web. Euclid's data covers a vast area of the sky through three mosaics. The release includes galaxy clusters, active galactic nuclei, and transient events. Notably, it features the first classification of over 380,000 galaxies and 500 candidates for gravitational lensing. ESA’s Director of Science, Prof. Carole Mundell, praised Euclid as a powerful tool for exploring the Universe and answering significant scientific questions. In just one week, Euclid has identified 26 million galaxies, with some located 10.5 billion light-years away. The mission plans to observe three specific areas of sky multiple times over the next several years, greatly increasing the data collected. By the end of its mission in 2030, Euclid will cover one-third of the entire sky with high-quality images. The mission utilizes advanced imaging technology to measure the shapes and distribution of galaxies precisely. This data helps scientists understand the cosmic web made of ordinary and dark matter, which plays a crucial role in galaxy formation and evolution. Experts emphasize that the fully realized potential of Euclid will provide deeper insights into dark matter and dark energy. Euclid is set to capture images of over 1.5 billion galaxies in six years, generating around 100 GB of data daily. Managing such a vast dataset presents challenges. To tackle this, scientists are using AI algorithms alongside thousands of human volunteers. These contributions helped create a detailed catalogue of more than 380,000 galaxies, classified by their features. Today’s release is just the beginning. It represents a small fraction of the total galaxies Euclid will image over its lifetime. The mission aims to provide valuable insights into galaxy evolution and broader cosmological questions. Euclid also studies gravitational lensing, where light from distant galaxies is bent by the mass of objects in the foreground. This affects how we see those galaxies. The mission has released a catalogue of 500 strong lens candidates previously unknown, which will help researchers learn more about dark matter distribution in the Universe.