Euclid (ESA)

Euclid is the European Space Agency’s mission to map the “dark universe”: the dark matter and dark energy that together dominate the cosmos. It launched on July 1, 2023, on a SpaceX Falcon 9 and surveys the sky from a halo orbit around the Sun-Earth L2 point. The plan is 14,000 square degrees in six years, through 2030, mapping up to two billion galaxies across more than a third of the sky. Its main tools are weak gravitational lensing and galaxy clustering, as described in the 2025 mission overview.

Flagship instruments

• 1.2-meter Korsch telescope.
• VIS: a visible-light imager for galaxy shapes.
• NISP: a near-infrared spectrometer and photometer for distances.

Recent results

The first Quick Release, Q1 (March 19, 2025), covered 63.1 square degrees of deep fields with 26 million galaxies and 500 strong-lens candidates; Euclid expects about 100,000 lenses by the end of the mission. AI plus 9,976 Galaxy Zoo volunteers classified more than 380,000 of those galaxies. In July 2026 the Wide Survey yielded 31 distant quasars, 12 at redshift 7 or above, and, with Keck follow-up, a new quasar distance record at redshift 7.77, about 670 million years after the Big Bang.

What to watch, 2026-2030

• November 2026: DR1-Foundation, raw and calibrated data for about 1,900 square degrees.
• Mid-2027: full DR1, with weak-lensing and galaxy-clustering science products.
• 2030: end of the six-year survey.

Why scientists are converging here

Euclid is one of the instruments that will decide whether DESI’s hint of evolving dark energy holds up. In our Research Pulse count, “Euclid” appeared in 155 astro-ph abstracts from April to September 2026, slightly fewer than the 166 in the previous six months; the cosmology products in mid-2027 are the data most teams are waiting for. It works alongside the Rubin Observatory and the Roman Space Telescope.