Plate Nº 44 · recorded November 14, 2026
Space & AstronomyReported finding
Euclid's First Big Data Release Charts 1 Billion Objects Across the Sky
ESA's Euclid releases DR1-Foundation: 13 months of data, 1 billion objects, and 14% of its final six-year sky survey toward a 3D dark matter map.
By James Calloway4 min read716 words
In brief
- DR1-Foundation captures light from more than 1 billion objects gathered over 13 months of observations.
- The release covers 1,900 square degrees — about 14% of the sky Euclid will map in its six-year mission.
- The surveyed area equals roughly 9,500 full moons on the sky.
- Euclid's eventual 3D map will exceed DESI's, the current largest, with more depth, volume and resolution from space.
- Featured targets include ring galaxy NGC 1291, 33 million light-years away, and galaxy cluster Abell 3128, 800 million light-years away.
ESA's Euclid telescope has released its first major data trove: 13 months of observations covering a patch of sky as large as roughly 9,500 full moons, with light from more than 1 billion objects. The release, called DR1-Foundation, is the foundation layer — the name is literal — for the mission's eventual 3D map of the universe.
That map is the whole point. Euclid exists to study dark energy and dark matter, the two invisible components that dominate the cosmos but reveal themselves only at enormous scales. To catch their effects, you need to image galaxy superclusters, the filaments they string along, and the voids between those filaments. The wider and deeper you look, the better your odds of pinning down what these things actually are.
What does this change for cosmology?
Not much yet, honestly. DR1-Foundation is a stepping stone, not a verdict. The data come from Euclid's Wide and Deep Surveys, the two campaigns that will form the backbone of the 3D map. Together they cover 1,900 square degrees of sky. That sounds vast. It isn't, relatively speaking — it's only about 14% of the sky Euclid will chart over its six-year mission.
The two surveys do different jobs:
- The Wide Survey is the primary campaign. It will eventually cover almost half of the galactic sky, imaging in visible and near-infrared light while also taking spectra — fingerprints of light that reveal, among other things, how far away a galaxy sits. This is the main cosmology workhorse, built to constrain dark energy and dark matter over a huge volume.
- The Deep Survey stares longer at smaller patches. It catches fainter quarry: dwarf galaxies, low-mass galaxies, tidal tails — streams of stars torn from galaxies by gravity — plus high-redshift galaxies and quasars from the universe's early days. It calibrates the Wide Survey and produces its own science thanks to its denser crop of sources.
Volume from one, depth from the other. A cosmological survey needs both, and claiming either alone would leave the picture lopsided.
How does Euclid stack up against DESI?
There's already a giant in this game. DESI, the Dark Energy Spectroscopic Instrument, has built the largest 3D map of the universe so far. Euclid's map will be bigger — more depth, more volume. And Euclid holds a structural advantage: it orbits in space, while DESI sits on the ground. No atmosphere means no atmospheric interference, which means sharper resolution. That's the promise. The delivered map, and whether it outperforms on the science, remains to be seen until the mission completes.
What else came with the release?
Euclid delivered a striking image of NGC 1291, a ring galaxy about 33 million light-years away, nicknamed the Golden Eye galaxy. It has an inner ring, an outer ring and an inner bar. Those rings may be scars of a past merger with a gas-rich galaxy — a plausible story, though mergers this ancient are easier to suggest than to prove.
The telescope also captured Abell 3128, a massive cluster 800 million light-years away containing hundreds of individual galaxies. Clusters like this pull double duty. They act as gravitational lenses — their gravity bends light from objects behind them — which reveals where dark matter concentrates. They also let cosmologists test Lambda-cold dark matter, the standard big bang model of the universe. And they help Euclid calibrate itself against known targets.
The mission has already notched some finds beyond surveys: a new comet, the most ancient quasar known in the universe, and fresh images of the Milky Way's crowded center.
The caveats
n This is an appetizer, as the mission's own framing has it, and appetizers don't fill you up. DR1-Foundation represents roughly a seventh of the final sky coverage, gathered in 13 of a planned 72 months. The headline science — real constraints on dark energy and dark matter — depends on the full six-year dataset. Early images, including a previous 60-square-degree taster that showcased targets from the Horsehead Nebula to the Perseus cluster, proved the instrument works. They didn't settle any debates.
Euclid is off to a strong start. Whether the feast lives up to the menu, we'll know only when the map is done.
via phys.org/rss-feed/ (Source)
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Staff writer covering regulation, policy and their impact on general science news at SciBeat.
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Nearby plates
- Euclid's First Data Release Images 900 Million Galaxies
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- Euclid's first major data release captures over 1 billion cosmic objects
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