Uitsnede van Abell 2390, waarop een groep gelensde sterrenstelsels te zien is. Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi
Uitsnede van Abell 2390, waarop een groep gelensde sterrenstelsels te zien is. Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi

The first scientific images from the Euclid telescope surpass all expectations

ESA has published five images taken with the Euclid space telescope. According to astronomers working with the data, these images surpass all expectations and demonstrate that Euclid is capable of unraveling the secrets of the universe. Scientists within the Euclid consortium, including Søren Larsen from Radboud University, can now search for orphan planets, use 'lensed' galaxies to study mysterious dark matter, and explore the evolution of the universe.

The new images are part of Euclid's Early Release Observations and are accompanied by the first scientific data from the mission, which were also published today, along with ten scientific articles that will be released soon. The first scientific data have been published less than a year after the launch of the space telescope and approximately six months after it sent its first full-colour images of the universe back to Earth.

Euclid

Euclid is a European mission, built and managed by ESA, with contributions from NASA. The Euclid consortium comprises over 2000 scientists from 300 institutions within and outside Europe. Many Dutch astronomers and data scientists are closely involved in processing and analysing the data generated by Euclid.

"Euclid is a unique, groundbreaking mission, and these are the first datasets being made public - it is a significant milestone," says Valeria Pettorino, ESA's Euclid Project Scientist. "The images and associated scientific findings are impressively diverse in terms of the observed objects and distances. They encompass a variety of scientific applications, yet they represent only 24 hours of observations. Koen Kuijken (Leiden Observatory) adds: "We are eager to work with the first major dataset from Euclid, which we expect in February 2025. These images once again show that the data exceed expectations!"

The complete set of early observations was focused on 17 astronomical objects, from nearby gas and dust clouds to distant clusters of galaxies, leading up to Euclid's main goal: unveiling the secrets of the dark cosmos and determining what makes the universe look as it does now.

Results

Euclid will trace the hidden web-like structures of the cosmos, map billions of galaxies in an area covering more than a third of the sky, investigate how our universe has formed and evolved throughout cosmic history, and study the most mysterious of the fundamental components: dark energy and dark matter.

The images taken with Euclid are at least four times sharper than those astronomers can capture with ground-based telescopes. They cover vast swathes of the sky with unparalleled depth, peering deep into the distant universe in both visible and infrared light.

While visually stunning, the images are much more than just pretty pictures; they reveal new physical properties of the universe thanks to Euclid's new and unique observational capabilities. Several accompanying scientific articles from the Euclid consortium will appear on the preprint server arXiv, along with five reference papers on the Euclid mission.

The impact of Euclid will be significant, as described in an extensive review article of the mission. Henk Hoekstra (Leiden Observatory), who coordinated the composition of the article, explains: "An average book has 50,000 words, just like the number of galaxies Euclid observes in one shot. Hubble has read a bookshelf in the past 30 years, while Euclid does that in a few days and reads the entire library in six years. You can learn a lot from the books on a single bookshelf, but in an entire library, you can discover much more."

The initial findings show that Euclid is capable of detecting free-floating planets (orphan planets, 'rogue planets' in English) with a mass only four times that of Jupiter in star-forming regions, studying the outer regions of star clusters in unprecedented detail, and mapping different star populations to investigate how galaxies have evolved over time. They also reveal how the space telescope can detect individual star clusters in distant groups and clusters of galaxies, identify new dwarf galaxies, and capture the light from stars that have been torn away from their parent galaxies. Euclid compiled this catalogue in just one day, identifying over eleven million objects in visible light and an additional five million in infrared light.

View the images

All high-resolution images, cutouts and accompanying papers are available on the websites of ESA and the Euclid consortium.

Header image: 

Cutout of Abell 2390, depicting a group of lensed galaxies. 
Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi