A space mission to map the Dark Universe

Welcome to the website of the Euclid Collaboration provided by the Euclid Project Scientist and the Euclid Science Operations Centre. This site is primarily meant to the scientists and engineers involved in the Euclid mission. For general public ESA webpages about Euclid, please check the "Links" provided on the left hand side of the page.

Euclid is a space-borne survey mission dedicated to investigate the origin of the Universe's accelerating expansion and the nature of dark energy, dark matter and gravity. Euclid will characterise the signatures of dark energy on the 3D distribution of cosmic structures. In 2012, Euclid was approved as the second Medium Class mission (M2) in the Cosmic Vision Programme for launch in 2020.

Watch the Euclid model in 3-D !

The mission is optimised to measure apparent shapes of galaxies, which are distorted by gravitational deflection of light due to dark matter concentrations, and to measure galaxy clustering, that is the non-random distribution of galaxies in the Universe resulting from the action of gravity. Euclid demands very high precision measurements and the ability to survey the sky at visible and near-infrared (NIR) wavelengths. Such requirements cannot be met from the ground, and calls for a wide-field Visible/NIR space mission. For more information see our SciTech site, and in particular the "red book"

The sky covered by Euclid

During its nominal mission of 6 years, Euclid will survey 15,000 deg2 of extragalactic sky. The image above is the Euclid reference survey fulfilling all mission specifications, and is created for the Mission PDR in October 2015. The image is a Mollweide projection of the entire sky in ecliptic coordinates, the ecliptic North pole is up. The ecliptic plane (horizontal band) and the galactic plane (u-shaped band) are avoided due to sky background disturbance. Different colours indicate different years during the survey (image courtesy Euclid Consortium).

News and Announcements


11-15 June 2018 Annual Euclid Consortium meeting (Bonn)
5-8 June 2017 Euclid Consortium Meeting, 100 years of Λ (London)
1 Dec 2016 Euclid Blue Grism workshop (IAP Paris)
20-23 Sep 2016 2016 Euclid Photometric Calibration workshop (ESAC)
30 May - June 2 2016 Annual Euclid Consortium meeting (Lisbon)
8-12 June 2015 Annual Euclid Consortium meeting 2015 (Lausanne)
10-11 Sep 2014 Euclid Science Team Meeting #9 (GSFC, Greenbelt MD)
8 May 2014 Euclid Science Team meeting #8 (Marseille)
5-9 May 2014 Annual Euclid Consortium Meeting 2014 (Marseille)
Mar 2014 NASA endorses funding for ENSCI, the US datacentre at IPAC
Nov 2013 Euclid Multi-Lateral Agreement was signed by the payload funding agencies.
Jul 2013 ESA selected Thales Alenia Space as the spacecraft prime contractor
13-15 May 2013 Annual Euclid Consortium Meeting (Leiden)
Jan 2013 NASA joined the mission
A Memorandum of Understanding between ESA and NASA was signed
Dec 2012 ESA selected Astrium Toulouse as the payload module prime contractor
15-16 May 2012 Euclid Mission Meeting (Copenhagen)
Oct 2011 Euclid selected for implementation



In the spotlight: Andrea Zacchei

January 2018


Andrea Zacchei is the Euclid Science Ground Segment Manager


Why did you join the Euclid team ?

I worked as LFI Data Processing Manager on Planck (ESA Mission) for 15 years and this gave me the possibility to acquire a lot of experience in space based programs. 
As soon as Fabio Pasian, former ECSGSM, for personal reasons, decided to resign I was appointed to cover his role. At that time (more than three years ago) I was not so happy as the workload on Planck was not yet finished and the one on Euclid was growing fast. BUT now I'm very excited to see how this project is evolving.


What do you see as the biggest challenge in Euclid ?

Due to the enormous amount of data that Euclid will use, the analysis will not be centralized. This means that we have to develop an infrastructure (Infrastructure Abstraction Layer, Data Transfer System, Archive System, Processing Coordinator, etc ...) able to allow the pipeline to be run on different Science Data Centers that will use a different hardware. Let me say that from the technical point of view this is very challenging and is going in the direction of a cloud system.

What are your expectations with Euclid ?

Planck provided us the most detailed image of the Universe immediately after the inflationary period. With Euclid I'm expecting to learn how the Universe evolved and the role of Dark Matter and Dark Energy. 
In few words try to understand better our Universe and this is simply the MAIN question.

If you had to define your work within Euclid with one word, what would it be ?

ONE WORD--> Networking
Talking to people, sending e-mails, attending telecons with some intelligent things to say... 
Managing the entire ECSGS where 15 countries are represented with more than 50 institutes participating is very complex, and the work required by the Project Office to organize it is huge. 
I think in any case that the project is going very well and this is because all people involved are excited by the scientific scope, so they dedicate to the project more than 100%.

IN THE PICTURE 2016-12-22


ESTEC - 22 Dec 2016 - A very important and essential part of the instrument specification is the on-ground characterisation of the flight detectors. The VIS and NISP instrument teams have built facilities at MSSL and CPPM, respectively, to carry out the characterisation tests for all detector units. The tests will take a significant amount of effort and time in 2017, considering the selection of the required amount of 16 H2RG and 36 CCD flight devices. This is mitigated by testing two or more devices in parallel using more than one cryostat. The first flight CCDs will be delivered to MSSL for characterisation by the end of 2016, the first NIR sensor systems for flight will arrive at CPPM in March 2017. Photo: Magdalena Szafraniec preparing the CCD testing facility in MSSL.

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