Illustration: ESA - C. Carreau
Scientists from The Open University form part of The European Space Agency (ESA) collaboration to build Euclid, a satellite which will help answer the important question on why the Universe is expanding at an accelerating rate, rather than slowing down due to the gravitational attraction of all the matter in it.
Andrew Holland, Professor of Electro-Optics at The Open University’s Centre for Electronic Imaging, said: “Cosmic acceleration was discovered in 1999, but we still don’t know what causes it. The term ‘dark energy’ often describes this force, and the Euclid collaboration between academia and industry will study the ‘dark Universe’, looking at the evolution and distribution of dark matter and dark energy.
“Scientists have recently come to the startling conclusion that ordinary matter - that is protons, neutrons, electrons and atoms that we understand well - account for only 4% of the known Universe; the remaining 96% is thought to be made up of the mysterious dark energy and dark matter.”
The Euclid spacecraft, a European venture led by ESA, will survey the sky, and a visible imaging instrument known as VIS will measure the shapes of distant galaxies using a digital camera with a large array of detectors called CCDs. The detectors, manufactured by Chelmsford-based e2v technologies PLC, will measure the precise shape of those galaxies. Foreground galaxies warp the space and time around them, according to Einstein's theory of gravity, and the shapes of background galaxies appear subtly distorted by these foreground warps. By measuring these subtle warps, Euclid will enable direct measurements of the amount and nature of dark energy in the Universe.
The harsh radiation environment around the spacecraft arising from the sun, often referred to as ‘space weather’, can adversely affect the CCD detectors, and with funding from the UK Space Agency, The Open University research team will start a five year programme to make detailed measurements of the radiation effects. Working in collaboration with e2v for detector manufacture, the research group will help UK industry achieve the best performance from their detectors. This will enable calibration and correction of the resulting images, so that any elongation measured by Euclid accurately predicts the presence of dark matter.
Euclid has now been adopted as an official ESA mission and solidifies the Euclid Consortium at the forefront of worldwide research into the ‘Dark Universe’. The satellite is due to launch in 2019.
Euclid was formally selected in October 2011 for flight, with the Euclid Consortium adopted to help build Euclid on June 20th 2012. ESA will provide to the Euclid mission the spacecraft (built by industry under contract), the launch on a Soyuz rocket from the Kourou base in Guyana, operations for at least 6 years, and mission archives. The EC will provide the scientific instruments for Euclid (VIS & NISP), the data processing and scientific analysis software and archiving as well as scientific leadership for the mission. The EC is comprised of nearly a 1000 scientists from hundreds of institutions in Austria, Denmark, Italy, Finland, France, Germany, Netherlands, Norway, Portugal, Romania, Spain, Switzerland and UK, as well as contributions from US laboratories.