Most detailed universe simulation yet: ESA’s Euclid project maps 3.4 billion galaxies
An international team of scientists from the Euclid Consortium has unveiled the most detailed virtual model of the Universe to date, simulating more than 3.4 billion galaxies. The synthetic dataset, known as the Flagship 2 mock catalogue, is designed to replicate what European Space Agency (ESA)'s Euclid space telescope will observe during its six-year mission to map a third of the sky.
Launched in July 2023, Euclid studies cosmic structures to shed light on dark matter and dark energy, the unseen forces shaping the Universe’s accelerating expansion. By pairing real telescope data with detailed simulations, researchers aim to sharpen analysis methods and unlock new insights into the large-scale structure of the cosmos.
“These simulations are essential for the Euclid mission,” explained Pablo Fosalba of the Institute of Space Sciences (ICE-CSIC), as per press release. “They allow us to test our analysis tools and prepare to handle the enormous amount of data that Euclid will provide.”
The catalogue describes each galaxy using more than 400 properties, including brightness, shape, velocity, and star formation rate. This unprecedented level of detail allows scientists to test and validate their pipelines before Euclid’s full data streams become available.
“This is a huge step for the scientific community, since it is now accessible for everyone,” added Jorge Carretero, researcher at the Port d’Informació Científica (PIC) and CIEMAT. “In addition, it can have many different scientific applications beyond the context of the Euclid mission,” he said according to the press release.
How the simulation works
The Flagship 2 catalogue was produced on Switzerland’s Piz Daint supercomputer, using custom algorithms developed at the University of Zurich. The computation tracked the gravitational evolution of more than four trillion particles to form the cosmic web, clusters, filaments, and voids shaped by both dark and visible matter.
The project demonstrates the cutting edge of big-data cosmology: petabyte-scale simulations, advanced algorithms, and high-performance computing combined to create a realistic universe. By making the dataset open via CosmoHub, the team is enabling researchers worldwide to explore complex cosmological questions without needing their own supercomputing resources.
