He cited 800 million galaxies, 20 million stars and millions of quasars, and wondered what these sources say about themselves, from their era of formation to the present day, and about our galaxy.
This catalogue shows, at a resolution never before achieved, hundreds of millions of celestial objects captured by the instrument's cameras.
According to the ESA, the release covers about thirteen months of observations and nearly 1,900 square degrees, or 14% of the area planned over six years.
A presentation video, released the same day, places the viewer at the heart of a universe reconstructed from one year of observations, with the telescope remaining pointed at the same portion of the sky.
This detailed three-dimensional mapping is set to continue for several years, with Euclid gradually expanding its observation areas.
In the meantime, the craft, 4.7 metres long and 3.7 metres wide, has already delivered unprecedented views of the Milky Way and discovered a comet.
Among the images is the galaxy Messier 81, with its broad spiral arms, located 12 million light-years away.
The catalogue is therefore not an endpoint: it opens a first scientific reading of a sky that will be mapped well beyond this initial release.
Euclid, in service since 2023, thus provides researchers with a first usable dataset for linking galaxy formation to the current structure of the universe.
Analyses of this first harvest must now clarify what these hundreds of millions of objects reveal, before the map expands further.