Euclid telescope releases first-year map of over a billion objects

The European space telescope Euclid on Thursday released the data from its first year of measurements: more than a billion cosmic objects in a stretch of sky as large as 9,500 full moons. Astronomers published twenty scientific papers at the same time, condensing the data into first findings.

The Netherlands plays a large role in the new analysis techniques, which partly use AI and are needed to handle the flood of data. Koen Kuijken of Leiden University, who has worked on Euclid from the start, said: "These are datasets that have no equal in astronomy." Gijs Verdoes Kleijn of the University of Groningen said ten data centres are used for the telescope's data, one of them in the Netherlands.

900 million

galaxies in the data

60 million

quasars, the extremely bright cores of distant galaxies

160 million

sources with colour spectra

At a press conference, Kuijken said each Euclid image is a hundred times as large as images from other famous space telescopes such as Hubble or James Webb. The images are also very sharp, he said, so you can zoom in again and again. On a laptop screen, that level of detail would show an individual bacterium.

Euclid launched in July 2023 and is making a 3D map of the universe. The survey is meant to take about six years. Its main aim is to learn the nature of dark matter and dark energy.

Kuijken said dark matter is responsible for everything clustering together into galaxies and larger structures, while dark energy drives the accelerating expansion of the universe. "We don't yet understand the physics of either one," he said.

Handling the flood of data needs new analysis techniques, partly using AI, and the Netherlands plays a big role in them. Verdoes Kleijn said the biggest challenge is making all the data reliably available to the astronomers who want to work with it.