ESA’s Euclid mission has unveiled a 208-gigapixel mosaic showing a vast area of the southern sky.
This preliminary data, covering more than 500 times the area of a full Moon, aims to shed light on dark energy by mapping billions of galaxies across 10 billion light-years.
The European Space Agency (ESA) has unveiled a stunning 208-gigapixel mosaic of images captured by Euclid, a space mission launched in 2023 with contributions from NASA. Euclid’s primary goal is to explore why the universe is expanding at an accelerating rate, a phenomenon linked to the mysterious force known as “dark energy.”
These new images were presented on October 15 at the International Astronautical Congress in Milan.
Dive into a snippet of the great cosmic atlas being produced by the ESA Euclid mission. This video zooms in on a 208-gigapixel mosaic containing about 14 million galaxies and covering a portion of the southern sky more than 500 times the area of the full Moon as seen from Earth. Credit: ESA/Euclid/Euclid Consortium/NASA, CEA Paris-Saclay, image processing by J.-C. Cuillandre, E. Bertin, G. Anselmi; ESA/Gaia/DPAC; ESA/Planck Collaboration
Details and Scale of Euclid’s Survey
The mosaic is made up of 260 observations, combining visible and infrared light, taken between March 25 and April 8, 2024. In just two weeks, Euclid managed to survey 132 square degrees of the southern sky—an area more than 500 times the size of a full Moon in the night sky.
This mosaic represents just 1% of Euclid’s six-year wide survey. Over this time, the telescope will study the shapes, distances, and motions of billions of galaxies, reaching as far as 10 billion light-years away. The mission aims to create the most extensive 3D map of the cosmos ever constructed.
This first piece of the map already contains around 100 million stars and galaxies. Some 14 million of these galaxies could be used by Euclid to study the hidden influence of dark energy on the universe.
“We have already seen beautiful, high-resolution images of individual objects and groups of objects from Euclid. This new image finally gives us a taste of the enormity of the area of sky Euclid will cover, which will enable us to take detailed measurements of billions of galaxies,” said Jason Rhodes, an observational cosmologist at NASA’s Jet Propulsion Laboratory in Southern California who is the U.S. science lead for Euclid and principal investigator for NASA’s Euclid dark energy science team.
Galaxies Galore
Even though this patch of space shows only 1% of Euclid’s total survey area, the spacecraft’s sensitive cameras captured an incredible number of objects in great detail. Enlarging the image by a factor of 600 reveals the intricate structure of a spiral galaxy in galaxy cluster Abell 3381, 470 million light-years away.
“What really strikes me about these new images is the tremendous range in physical scale,” said JPL’s Mike Seiffert, project scientist for the NASA contribution to Euclid. “The images capture detail from clusters of stars near an individual galaxy to some of the largest structures in the universe. We are beginning to see the first hints of what the full Euclid data will look like when it reaches the completion of the prime survey.”
Visible as well are clouds of gas and dust located between the stars in our own galaxy. Sometimes called “galactic cirrus” because they look like cirrus clouds at Earth, these clouds can be observed by Euclid’s visible-light camera because they reflect visible light from the Milky Way.
Complementary Missions and Extended Research
This mosaic release is just a taste of what’s to come from Euclid. The mission plans to release 53 square degrees of the Euclid survey, including a preview of the Euclid Deep Field areas (see image below), in March 2025 and to release its first year of cosmology data in 2026.
NASA’s forthcoming Nancy Grace Roman mission will also study dark energy — in ways that are complementary to Euclid. Mission planners will use Euclid’s findings to inform Roman’s dark energy work. Scheduled to launch by May 2027, Roman will study a smaller section of sky than Euclid but will provide higher-resolution images of millions of galaxies and peer deeper into the universe’s past, providing complementary information. In addition, Roman will survey nearby galaxies, find and investigate planets throughout our galaxy, study objects on the outskirts of our solar system, and more.
For more on this, see Euclid “Dark Universe” Telescope Unveils Stunning 208-Gigapixel Window Into the Cosmos.
More About Euclid
Euclid is a European mission led by the European Space Agency (ESA) with significant contributions from NASA. The scientific work behind the mission is supported by the Euclid Consortium, a group of over 2,000 scientists from 300 institutes across 15 European countries, along with researchers from the United States, Canada, and Japan. The consortium is responsible for the scientific instruments and data analysis. Thales Alenia Space was selected by ESA as the prime contractor for building the satellite and its service module, while Airbus Defence and Space developed the payload module, including the telescope. Euclid is part of ESA’s medium-class missions within its Cosmic Vision Program.
NASA supports the Euclid mission through three key science teams. NASA’s Jet Propulsion Laboratory (JPL) played a crucial role in designing and building the sensor-chip electronics for the Near Infrared Spectrometer and Photometer (NISP) instrument. JPL also oversaw the procurement and delivery of NISP detectors, which were tested at NASA’s Detector Characterization Lab at Goddard Space Flight Center in Maryland. The Euclid NASA Science Center at IPAC (ENSCI) at Caltech in Pasadena, California, will archive the scientific data and assist U.S.-based scientists with their investigations. JPL is managed by Caltech.