# Euclid by European Space Agency Canonical page: https://technooptimist.io/spaceflight/euclid Frontier: [Spaceflight](https://technooptimist.io/spaceflight.md) · Field: Space telescopes · Company: [European Space Agency](https://technooptimist.io/companies/esa.md) Stage: Deploy (4 of 5: Research → Proto → Pilot → Deploy → Scaling) Updated: last update 2026-07-06, facts checked 2026-10-11 Goal: Measure what dark energy and dark matter are by mapping how matter is spread through space and time across a third of the sky, using the shapes and distances of over a billion galaxies. Status: Surveying since 2024; first big data release (about 1,900 sq deg) due 12 November 2026. Next milestone: DR1-Foundation: images and catalogues for ~1,900 sq deg, target 12 Nov 2026 (slipped 1 months; originally Oct 2026) ## Milestones | Status | Milestone | Date | Slip | | --- | --- | --- | --- | | Done | Launch on Falcon 9 to Sun-Earth L2 | 1 Jul 2023 | | | Done | First full-colour images released | 7 Nov 2023 | | | Done | Main six-year survey begins | 14 Feb 2024 | | | Done | First quick data release: 63 sq deg, 26 million galaxies | 19 Mar 2025 | | | Done | Second quick release, incl. Milky Way bulge images | 24 Jun 2026 | | | Current | DR1-Foundation: images and catalogues for ~1,900 sq deg | 12 Nov 2026 | +1 mo (originally Oct 2026) | | Planned | Full DR1 with cosmology-ready products | 2027 | | | Planned | Data Release 2 | Jun 2029 | | | Planned | Data Release 3, final survey data | Oct 2031 | | ## Upcoming events - **12 Nov 2026**: DR1-Foundation: images and catalogues for ~1,900 sq deg (slipped 1 mo) - **2027**: Full DR1 with cosmology-ready products - **Jun 2029**: Data Release 2 - **Oct 2031**: Data Release 3, final survey data ## Most important updates - **6 Jul 2026**: Euclid finds the most ancient quasars known, from the Universe's first 670 million years. Using Wide Survey data, astronomers found 31 new early-Universe quasars, 12 at redshift 7 or above, more than doubling the known number that old. ([our story](https://technooptimist.io/stories/euclid-finds-the-most-ancient-quasars-known-from-the-universe-s-first-1df82764.md) · [original source](https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_discovers_the_most_ancient_quasar_in_the_Universe)) - **24 Jun 2026**: Euclid images the Milky Way's crowded centre: 60 million stars in one mosaic. ESA released the largest and most detailed visible-light image yet of the Milky Way's centre, a nine-pointing mosaic taken in about 26 hours. ([our story](https://technooptimist.io/stories/euclid-images-the-milky-way-s-crowded-centre-60-million-stars-in-one-39427952.md) · [original source](https://www.esa.int/Science_Exploration/Space_Science/Euclid/ESA_s_Euclid_captures_the_Milky_Way_s_crowded_heart)) - **15 Jun 2026**: ESA splits Euclid's first big data release: images in November 2026, cosmology products in mid-2027. ESA said Euclid's Data Release 1 will come in two stages. ([our story](https://technooptimist.io/stories/esa-splits-euclid-s-first-big-data-release-images-in-november-2026-ae116d2e.md) · [original source](https://www.cosmos.esa.int/web/euclid/dr1-timeline)) - **19 Mar 2025**: Euclid's first quick data release: 26 million galaxies in a week of observing. ESA released Euclid's first batch of survey data, covering three deep fields totalling 63.1 square degrees. ([our story](https://technooptimist.io/stories/euclid-s-first-quick-data-release-26-million-galaxies-in-a-week-of-d31d7269.md) · [original source](https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_opens_data_treasure_trove_offers_glimpse_of_deep_fields)) ## Current obstacles - **Processing a survey this large takes time**: ESA split DR1 in two in June 2026: images and catalogues in Nov 2026, the cosmology products in mid-2027, to finish validating them. - **Stray sunlight**: A small gap in the hull let sunlight reach the visible camera early on; turning the spacecraft a few degrees blocked it. ## Physics limits - **The lensing signal is smaller than the noise**: Galaxies have random shapes much larger than the stretch caused by dark matter, so only averages over millions of galaxies work, and the telescope's own optical distortions must be known even better. - **There is only one sky to sample**: Large-scale patterns are measured from a limited number of giant structures in the observable Universe. Past a point, a bigger telescope cannot shrink that statistical uncertainty. ## How it works ### Weak lensing: Weighing invisible matter by bent light Dark matter bends light from galaxies behind it, slightly stretching their shapes. Averaging the shapes of about a billion galaxies maps where the mass is. ### 3D map: Distances from spectra The infrared instrument splits galaxy light into spectra to find distances, turning a flat picture into a 3D map of how galaxies cluster over 10 billion years. ### Two eyes: One mirror, two instruments A 1.2 m mirror feeds a 600-megapixel visible camera for sharp shapes and an infrared camera and spectrometer for colours and distances, on the same patch. ### Survey: Tiling a third of the sky Euclid steps across 14,000 sq deg over six years; three deep fields are revisited 30 to 52 times to see fainter, more distant galaxies. ## Spec sheet | Spec | Euclid | Provenance | | --- | --- | --- | | Primary mirror | 1.2 m | reported | | Visible camera | About 600 megapixels | reported | | Infrared instrument | About 65 megapixels | reported | | Wavelengths | 530–2,020 nm (visible to near-infrared) | reported | | Wide survey area | 14,000 sq deg (a third of the sky) | reported | | Galaxies imaged by mission end | 1.5 billion+ | reported | | Data sent home | About 100 GB per day | reported | | Nominal mission | 6 years (to 2030) | reported | Provenance: reported = stated by the company; estimated = our estimate; sample = a sample figure. ## About European Space Agency ESA is the European intergovernmental space agency with 23 member states. It operates Earth observation systems, the International Space Station, deep-space missions and the Ariane rocket family. The Hera mission is ESA's planetary-defence follow-up to NASA's DART impact test. - Develops Ariane rockets and Copernicus Earth-observation satellites; participates in the International Space Station. - Hera mission to asteroid Didymos measures how NASA's 2022 DART impact deflected it, validating planetary defence. - Multinational agency with 23 European member states; 2026 budget €8.26 billion. - Founded: 1975 - Headquarters: FR - Status: government - Website: https://www.esa.int - Partners, customers, investors: NASA (partner); Airbus Defence and Space (supplier); Thales Alenia Space (supplier) Company page: https://technooptimist.io/companies/esa.md ## Related programs More from European Space Agency: - [Hera](https://technooptimist.io/spaceflight/hera.md) (Deploy) - [ExoMars Rosalind Franklin rover](https://technooptimist.io/spaceflight/rosalind-franklin-rover.md) (Pilot) - [PLATO](https://technooptimist.io/spaceflight/plato.md) (Proto) - [JUICE (Jupiter Icy Moons Explorer)](https://technooptimist.io/spaceflight/juice.md) (Deploy) - [Ariel](https://technooptimist.io/spaceflight/ariel.md) (Proto) - [Ramses](https://technooptimist.io/spaceflight/ramses.md) (Proto) Everything in Spaceflight: https://technooptimist.io/spaceflight.md --- The Techno Optimist tracks every frontier of technology, program by program: https://technooptimist.io/ (a Markdown version of any page: add .md to its URL; site map for agents: https://technooptimist.io/llms.txt). 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