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.

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).

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.

IN THE PICTURE 2016-12-19


CERN - 19 Dec 2016 - The Euclid Consortium Lead, Yannick Mellier (right), together with Euclid's Project manager of ESA, Giuseppe Racca, visited CERN to present the science of Euclid as well as ESAs organisation and approach to construct the space mission. Euclid and the LHC share a common objective: detection and characterisation of dark matter. Highlights of the visit was to learn about the latest results of the Alpha Magnetic Spectrometer (AMS) - the instrument residing at the ISS - and to see one of the CERN experiments, ATLAS, from nearby. They were hosted by prof. Peter Jenni, former spokesperson of ATLAS. Although ATLAS is about as costly as Euclid, it clearly has a more generous mass budget than Euclid.

IN THE PICTURE 2014-03-18

Frank Grupp Luis Venancio

ESTEC - 18 March 2014 - It is motivating to see (and touch!) real space hardware, especially concerning one's own mission. During the kick-off meeting of the NISP preliminary design review (PDR), Dr. Frank Grupp (MPE Garching) displayed a prototype of one of the NISP CALA lenses. For many the size of the lens of 16 cm diameter was most striking, giving a better impression of the size of the opto-mechanical assembly of NISP. Left photo: Frank Grupp showing the lens, Right photo: telescope engineer Luis Miguel Gaspar Venancio and project manager Giuseppe Racca inspecting the lens.



November 2016

Dr Ginevra Favole recently joined the Euclid SOC at ESAC as Research Fellow.

Before joining ESAC in October 2016, I was a PhD student at IAA (Granada) and IFT-UAM (Madrid). My research is mostly focused on measuring and modelling the galaxy clustering and weak lensing signals in galaxy populations that differ in color, luminosity and star-formation history. These measurements are powerful cosmological probes that allow us to understand how the large scale structure of our Universe formed and grew in time until the present configuration. In particular, I have developed numerical algorithms to reproduce the galaxy two-point correlation function using high-resolution N-body cosmological simulations and SHAM or HOD techniques. These models allow us to build robust predictions of the galaxy halo occupation distribution within the cosmic web. In one word, they help us to build detailed three-dimensional maps of the Universe we see today where dark matter, dark energy and baryons coexist.

Why did you join the Euclid team? I joined the Euclid team since I am primarily interested in extending my research, so far mostly based on SDSS and SDSS-III/BOSS low-redshift optical data, to the high-redshift emission line galaxies that Euclid will observe in the infra-red. In the near-future, large samples of galaxies with unprecedented imaging quality and spectral resolution will be available. This represents a unique opportunity for us to find and connect the missing pieces of the cosmological puzzle.

What do you see as the biggest challenge in Euclid? Euclid will provide about 50 million galaxy spectra with Halpha emission line fluxes out to redshift z=2. This will allow us to precisely trace the baryon acoustic oscillation feature in their clustering signal and hopefully reduce the errors at the 1% level.

What about your expectations with Euclid? My expectation with Euclid is to really see an improvement, in terms of image quality, spectral resolution and statistical significance, compared to the previous surveys. I hope this mission will make the difference in our understanding of the structure formation process. I hope in a few years we will be able to define the nature of dark energy and to explain why the Universe is expanding at an accelerating rate.

Dr Maggie Lieu recently joined the Euclid SOC as Research Fellow.

I completed my undergraduate degree in Astronomy, Space Science and Astrophysics at the University of Kent with a year in UCLA. My Masters project involved creating SPH simulations of molecular clouds and the effects of FUV radiation on star formation. I later switched to galaxy clusters for my PhD, at the University of Birmingham to pursue my main science interest in cosmology. There, my research focussed on the mass measurements of galaxy groups and clusters which is crucial for cluster cosmology and involved working closely with optical, X-ray, weak-lensing data.

Why did you join the Euclid team? Weak gravitational lensing is the ideal tool to estimate cluster mass since it is neither sensitive to the dynamical state of the cluster or the nature of the mass. However, current limitations include the susceptibility to PSF/atmospheric effects, deep and wide coverage and also the uncertainties in redshift. Euclid will offer unprecedented shape measurements required for my weak lensing research and the synergies with upcoming surveys e-Rosita and LSST will facilitate considerable progress in the field of cluster cosmology.

What do you see as the biggest challenge in Euclid? I think the biggest challenge in Euclid is processing the large amount of data it will produce into scientifically accurate results. Weak gravitational lensing relies on the statistical averaging of many background galaxies in-order to reduce shape noise. Euclid will generate several petabytes of data covering 15000 deg^2 of the sky, leading to an era where we will no longer be restricted from abundance of high-quality lensing data but on methods to quickly extract accurate information from this upcoming big data survey.

What are your expectations with Euclid? I'm expecting Euclid to be absolutely epic! Aside from my own field, Euclid will cover many other science areas - including unravelling the mysteries of the universe (the nature of dark matter, dark energy and tests of gravity), identifying and mapping local objects such as asteroids to distant quasars and possibly even detecting the mythical Planet X, if such a planet exists. The launch of Euclid will be a very exciting time for science and I'm extremely happy to be able play a part in it.

News and Announcements


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