• The Euclid mission has captured its first full-color images—the sharpest ever obtained over such a large area of the sky and at such great distances. It will create the most extensive and accurate 3D map of the universe to study the dark universe.
• A group of researchers from CITIC at the University of A Coruña (UDC), led by Carlos Dafonte and Minia Manteiga, are participating in the mission by providing Artificial Intelligence tools to classify the observed objects.
• In the months following the launch, Euclid’s scientific team has been making final adjustments ahead of routine scientific observations beginning in early 2024.

The Euclid space mission of the European Space Agency (ESA), launched on July 1st, has revealed its first full-color images of the universe. Never before has a space telescope been capable of capturing such sharp astronomical images over such a wide area of the sky and at such a great distance—up to 10 billion light-years. These five images illustrate Euclid’s potential and demonstrate that the telescope is ready to create the most extensive 3D map of the universe to date, as it captures images up to 10 billion light-years away.

Spain’s contribution to the Euclid telescope’s payload has been coordinated among the Institute of Space Sciences (ICE-CSIC), the Institute for High Energy Physics (IFAE), the Institute of Space Studies of Catalonia (IEEC), the Port d’Informació Científica (PIC), the Polytechnic University of Cartagena (UPCT), and the Institute of Astrophysics of the Canary Islands (IAC). In addition, around 100 scientists from over 20 Spanish institutions are preparing to scientifically exploit the mission in order to unravel the mysteries of the dark universe.

Among them stands out the work of a research group at CITIC led by Carlos Dafonte, who joined the Euclid mission in 2022, one year before the satellite’s launch. Their role within the consortium of over 2,000 researchers from across Europe is to study the data collected by the NISP-SPEC infrared instrument to separate stellar objects from galaxies and contribute to characterizing the coolest stars and substellar objects such as exoplanets in the Milky Way.

Extending the Gaia Mission

“Euclid opens an unprecedented window into the cold and dark universe, and it will allow us to extend part of the Gaia survey to the coolest stars in the Milky Way and to other objects such as brown dwarfs or planets, which Gaia can hardly observe,” says Minia Manteiga, a researcher at CITIC. It is interesting to note that while our galaxy contains 100 billion stars, of which Gaia detects about two billion, our visible universe contains around 100 billion galaxies, and Euclid will capture images of approximately two billion of them.

“We aim to use the AI algorithms developed by our group to contribute to the analysis of the information collected by the space telescope, particularly to distinguish and separate observations coming from Milky Way stars from those coming from distant point-like galaxies,” explains Carlos Dafonte. The Galician group is part of the so-called Legacy Survey, which aims to process the survey’s overall information and provide relevant astrophysical data based on the observations.

Investigating Dark Matter and Energy

The mission aims to investigate dark matter and dark energy, which make up 95% of the cosmos. The nature of these components is still unknown, as their presence causes subtle changes in the appearance and movements of the observable universe. To reveal the influence of dark matter and dark energy on the visible universe, Euclid will, over the next six years, observe the shapes, distances, and movements of billions of galaxies up to 10 billion light-years away. In doing so, it will create the most extensive 3D map of the universe to date. Euclid’s survey of the cosmos is exceptional in its ability to produce remarkably sharp visible and infrared images of large regions of the sky in a single shot.

The released images reflect this special capability of Euclid: the observations show the full range of celestial objects—from bright stars to faint galaxies—while remaining extremely sharp, even when zooming in on distant galaxies.

Over six years, Euclid will study one-third of the sky with unprecedented precision. As the mission progresses, the Euclid data bank will be published annually and made available to the global scientific community through the Astronomy Science Archive hosted at ESA’s European Space Astronomy Centre in Spain.