The Great Cosmic Atlas Begins: Euclid’s 208-Gigapixel Image Maps 14 Million Galaxies

ESA scientists today revealed the first chunk of what will be the largest-ever 3D map of the cosmos.

The sparkling purplish-blue tapestry showcases data from 260 observations by the Euclid space telescope, the agency’s cutting-edge dark matter observatory. Over the telescope’s projected six-year lifetime, it will collect data that will help scientists understand the natures of dark matter and dark energy, which together comprise 95% of the known universe.

The 208-gigapixel image showcases an area of the southern sky about 500 times the area of the full Moon, as seen between March 25, 2024 and April 8, 2024. The image mosaic is just 1% of the wide survey Euclid will ultimately capture, which will include billions of galaxies extending far into the universe’s past. This first image shows 14 million galaxies, as well as tens of millions of stars from our own Milky Way.

“This stunning image is the first piece of a map that will reveal more than one third of the sky in six years,” said Valeria Pettorino, a Euclid project scientist at ESA, in a Max Planck Institute for Astronomy release. “This is just 1% of the map, and yet it is full of a variety of sources that will help scientists discover new ways to describe the Universe.”

The above image of a spiral galaxy is a fraction of the mosaic included at the top of this article. The area in the image is zoomed in about 600 times compared to the full-size mosaic, and shows a galaxy about 420 million light-years from Earth. The total area of the above image is just 0.0003% of the 208-gigapixel image—which itself only accounts for 1% of the total Euclid wide survey.

According to the institute release, about 12% of the survey has been completed so far, with about 100 gigabytes of data sent to Earth from the spacecraft each day. This data will do more than compose pretty pictures—it’ll clue scientists into the distribution of dark matter throughout the universe, as well as phenomena where dark matter manifests itself, like in gravitational lenses.

The Euclid team published the $1.4 billion spacecraft’s first images in November 2023, showcasing what the space observatory was capable of. Those images included shots of the Perseus galaxy cluster, spiral and irregular galaxies, a globular cluster, and the Horsehead Nebula, and came on the heels of test images revealed to the public in August 2023.