ESA’s Euclid sets off on dark matter mission

The European Space Agency’s (ESA) Euclid science spacecraft is carrying a high-precision 1.2m diameter reflecting telescope and payload module designed and built by Airbus that will enable the spacecraft to explore the composition and evolution of the Universe, including the role of dark matter and dark energy.

Built by Thales Alenia Space for ESA, Euclid will collect high-resolution images in visible and infrared wavelengths. Within six years of observation, covering over one third of the entire sky, Euclid will measure the shapes of, and distances to, more than one billion galaxies. NASA’s forthcoming Nancy Grace Roman mission, scheduled for launch in 2027, will study a smaller section of sky than Euclid, but it will provide higher resolution images of millions of galaxies and look deeper into the universe’s past.

In a statement, Jean-Marc Nasr, head of Space Systems at Airbus said: “Euclid is another world-inspiring space mission that will aid humanity’s understanding of the structure and evolution of the Universe. This is the largest telescope with the highest optical performance ever designed and integrated by Airbus.”

Euclid will create a map of the large-scale structure of the Universe and will explore how the Universe has expanded and how structure has formed over cosmic history, revealing more about the role of gravity and dark energy.

Euclid will also examine so called ‘weak lensing’, an effect that distorts the shapes of distant galaxy images due to the presence of dark matter between the Earth and those galaxies.  In this way it will map out the distribution of dark matter across the Universe with unprecedented accuracy.

Euclid will reach its operational orbit around Lagrange 2 four weeks after launch when testing will begin, with full operations expected to start after three months. Once in use, the full silicon carbide (SiC) telescope – with a focal length of 25m – will feed two scientific instruments: VIS, which takes very sharp images of galaxies over a large fraction of the sky, and NISP, which can analyse galaxies’ infrared light by wavelength to accurately establish their distance.