Euclid releases Flagship 2: The biggest and most detailed universe simulation ever made

The Euclid Consortium, part of the European Space Agency’s Euclid space telescope mission, has just released Flagship 2—the largest and most detailed computer simulation of the universe to date. This digital model maps an incredible 3.4 billion galaxies and tracks the gravitational pull of over 4 trillion particles. The simulation offers scientists a virtual universe to help understand and analyze the vast amount of data Euclid is collecting.

Flagship 2 is the largest and most detailed simulation of the universe ever made. It shows how galaxies form and cluster under gravity, creating the cosmic web pattern seen in real observations.

A simulation is like a virtual model or digital copy of something real—in this case, the universe. Scientists create simulations on powerful supercomputers to mimic the behavior of galaxies, stars, and cosmic forces based on current scientific knowledge

What is the Euclid Space Telescope?

Euclid is a space telescope launched by the European Space Agency (ESA) in July 2023. It orbits about 1.5 million kilometers from Earth, positioned at a special spot called the Sun-Earth Lagrange Point 2 (L2). Its mission is to explore the mysterious parts of our universe called dark matter and dark energy. Euclid does this by taking detailed pictures of billions of galaxies and measuring how they move and group together, helping scientists learn why the universe is expanding faster over time.

The Euclid mission aims to study mysterious dark matter and dark energy, which make up almost 95% of the universe but remain poorly understood. By comparing Euclid’s observations with the simulation, scientists hope to test and improve our current understanding of how the universe works.

The simulation was created using a powerful supercomputer in Switzerland in 2019 and developed by astrophysicist Joachim Stadel and his team. Stadel explained, “It was a huge challenge to simulate such a large portion of the Universe at this resolution in a single calculation.” Flagship 2 is designed to reproduce what Euclid’s telescope actually sees as it surveys about one-third of the sky and looks back in time up to 10 billion years.

Why is Flagship 2 important?

Euclid produces huge amounts of data by mapping one-third of the sky and looking back in time up to 10 billion years. Flagship 2 helps scientists by providing a realistic mock universe to test their data analysis tools, find possible problems, and predict new discoveries.

Julian Adamek, a collaborator, said the simulation is crucial for preparing to analyze the massive flow of data from Euclid:“It will be exciting to see whether the model holds up against Euclid’s high-precision data – or whether we uncover signs of new shortcomings.”

FAQ:

Q: What is Flagship 2?
A: Flagship 2 is the largest computer simulation of the universe ever made, showing billions of galaxies and trillions of particles interacting under gravity.

Q: How big is the area Euclid is studying?
A: Euclid is mapping about one-third of the entire night sky, covering billions of galaxies.

Q: What can Euclid and Flagship 2 tell us about dark energy?
A: They can reveal if dark energy has changed over time or behaves differently than current models say, helping explain why the universe’s expansion is speeding up.

Q: When will more data from Euclid be released?
A: The first data was released in March 2025, with more expected in October 2026.