The newly released data cover about 1,900 square degrees, roughly 14% of the sky area Euclid is planned to map. They also include more than 60 million potential quasars — blazing objects at the centres of distant galaxies, powered by supermassive black holes.
The goal is to shed light on two of the biggest mysteries in cosmology: the nature of dark energy and dark matter. These are thought to make up about 70% and 25% of the universe respectively.
ESA said the release, known as DR1-Foundation, was published on 12 November 2026. Reuters reported that the data come from about 13 months of observations and form part of a six-year effort to finish the largest three-dimensional map of the cosmos by 2031.
The release includes a large set of candidates for strong gravitational lensing, long considered rare. Experts previously knew of about 1,000 such cases. Euclid's data contain about 15,000 probable cases, with an estimated 170,000 expected by the end of the mission, Taylor said.
The effect is significantly boosted by dark matter, which increases a galaxy's mass and therefore its gravitational influence. How the mysterious substance is distributed in a galaxy depends on its properties, which is why the lensing can be diagnostic.
"With strong gravitational lensing, you find out how the dark matter is clumping and that's very diagnostic of the type of matter that it is, because different types of matter can clump in very different ways,"Taylor said.
Taylor said that by studying strong gravitational lensing, scientists may be able to rule out different theories of dark matter."So if you're looking for where the next breakthrough will be in the properties of dark matter and what dark matter actually is, there's a good chance — I can't say it's certain — but there's a good chance it might come from strong gravitational lensing,"Taylor said.
A further data release was expected next summer, Taylor added. It is due to include results on the distribution of galaxies and on weak gravitational lensing — subtle distortions of distant objects by dark matter in the foreground.
"We can use that pattern of distortions to actually make a map of where all the dark matter is in the universe,"Taylor said, adding that scientists could then work out its statistical properties and compare the results with different theories.
"Depending on the type of dark matter, the type of dark energy, we're expecting to see slightly different patterns on the sky,"Taylor said.
"It's the biggest high-resolution image of the universe we've ever had,"Taylor said."It's opening up that high resolution of the whole sky, the whole universe."The volume is already beyond visual inspection:"No human eyeball is able to look at all of the Euclid data any more.".