Euclid Approved for Launch in 2023
October 27th, 2022

The Euclid mission will investigate dark energy, the unknown cause of the accelerating expansion of the Universe, as well as dark matter, invisible but holding cosmic large-scale structure together with its gravity. On October 20, 2022, @ESA_Euclid, the official ESA feed of the Euclid mission, tweeted: “Few hours ago the ESA Council made the decision about the @ESA_Euclid launcher: ESA’s proposal to use the SpaceX vehicle Falcon 9 was approved for a launch in 2023” (click here to see the original tweet). The launch is planned for July to September 2023.

Euclid will map the large-scale structure of the Universe with photometry and spectroscopy over approximately 15,000 square degrees of the extragalactic sky - or nearly half of the full sky excluding the regions dominated by the stars in our Milky Way galaxy. Euclid consists of a 1.2m space telescope with two instruments: VIS and NISP. VIS is an optical camera for photometry (550-900nm, 0.56 sq deg FoV, 0.1 arcsec pixels). N ISP is a near infrared (NIR) camera that does double duty as a photometer (YJH) and a spectrometer (three 1.25-1.85 microns red grisms and one 0.92-1.3 micron blue grism, 0.55 sq deg FoV, 0.3 arcsec pixels, R~380 for 0.5 arcsec radius objects). VIS takes advantage of the high resolution afforded by a space telescope to make very accurate measurements of galaxy shapes for ~1.5 billion galaxies. NISP makes good use of the very low background in space to make precise measurements of the NIR fluxes of galaxies and to accurately measure the redshifts to ~30 millions of galaxies.

Euclid will measure galaxies out to distances which corresponds to a look-back time of about 10 billion years, covering the period over which dark energy accelerated the expansion of the Universe. Euclid is optimized for two primary cosmological probes: weak gravitational lensing (cosmic shear measurements), and galaxy clustering (baryon acoustic oscillation and redshift space distortion measurements). Euclid will enable other constraints on dark energy, as well as precise constraints on initial conditions in the Universe. In addition, Euclid will enable unprecedented advances across the range of astrophysics topics, from objects in our own Solar System to the light of the first stars detected in background fluctuations. Euclid will deliver high quality morphologies, masses, and star-formation rates for billions of galaxies out to z = 2, over the entire extragalactic sky. It will revolutionize our understanding of the Milky Way halo.

In January 2013 NASA joined the mission. NASA has contributed 16 state-of-the-art infrared detectors and associated cold electronics, and four spare detectors, for the NISP instrument on Euclid. In addition, NASA nominated three U.S. science teams for the Euclid Consortium. Today, more than 100 U.S. scientists and engineers are members of the Euclid Consortium, an international body of more than 1,000 members who oversee development of the instruments, manage science operations and analyze data.

NASA has established the Euclid NASA Science Center at IPAC (ENSCI) in order to support US-based investigations using Euclid data. ENSCI participates in the Euclid Consortium’s Science Ground Segment, providing algorithm and software development, participating in data quality assurance, and performing data processing. In addition, ENSCI will support the US research community by providing expert insight into the Euclid surveys, data processes, calibration, and products.

Euclid has completed its integration, and is in its final stages of testing before launch. For more about Euclid, go to the ENSCI website at, and the Euclid Consortium website at