ESA mission to study the ‘dark side’ of the Universe passes important test

In 2020, the European Space Agency (ESA) will launch the Euclid mission, with the ambition of tracking the shapes and positions of 2 billion galaxies, covering more than a third of the sky. The Euclid mission will allow us to understand the properties of matter and dark energy, and thus better understand the formation and evolution of the Universe. Last week, the first step towards making this ambitious mission a reality was taken, with the approval of the so-called Preliminary Design Review, in which researchers from the Institute of Astrophysics and Space Sciences (IA) participated . With this approval, there is confidence in the capabilities of the spacecraft and the instruments that will be built, and we can move on to the next step – “cutting metal”, in the words of ESA.

The IA team's work consisted of “delivering a complete observation plan for the six-year duration of the mission, demonstrating that it is actually possible to monitor more than a third of the sky, with the quality necessary to achieve the mission's scientific objectives,” describes Ismael Tereno, team coordinator. The test demonstrated that the combined performance of the spacecraft, telescope and instruments will enable the massive amount of data needed for the mission's scientific goals to be obtained.

 António da Silva, Euclid consortium board member and national coordinator, commented: “This contribution is part of Portugal’s technical responsibilities in the consortium, and allows national scientists to participate in the exploitation of data from this important mission during its proprietary period.” He also adds that “The merit of the team’s work was recognized by the consortium, which reflects the excellence and high level of internationalization of science carried out in Portugal in this area.”

Portugal joined the Euclid consortium in 2012 , through a multilateral agreement signed by the FCT, representing Portugal. FCT is a member of the Steering Committee of the consortium, which currently includes scientists from 14 European countries (Austria, Belgium, Denmark, France, Finland, Germany, Italy, the Netherlands, Norway, Portugal, Romania, Spain, Switzerland and the United Kingdom) as well as several scientists from the USA, including 40 appointed by NASA. The Portuguese participation includes 20 scientists, from different institutions, coordinated by IA.

It is now known that dark matter and energy constitute a large part of the matter and energy that exists in the Universe. In fact, normal atoms account for less than 5% of the matter in the Universe. This “dark side” is not, however, visible; its presence is inferred. Dark matter is inferred from measurements of alignments in the orientations of distant galaxies. Dark energy explains the speed of expansion of the Universe, measured by the distribution of galaxies in space. By tracking more than 2 billion galaxies with unparalleled precision, the Euclid mission will enable astronomers to understand the properties and behavior of dark matter and dark energy, as well as to study the mystery of the recent expansion of the Universe.

The mission Euclid It was proposed to ESA in 2007, selected as the agency's second medium-class mission in 2011, and formally adopted in 2012 (the year Portugal joined the consortium). The mission is scheduled to launch in December 2020 from Europe's spaceport in Kourou, French Guiana, aboard a Russian Soyuz rocket. It will describe an orbit about 1.5 million kilometers away from Earth. With the Preliminary Design Review test over, the next test will be in 2 years – the so-called Critical Design Review – after which, if all goes well, the Euclid spacecraft will be assembled.

The four IA researchers, members of the Euclid Sky Survey Working Group (ESSWG), are: António da Silva (IA and Faculty of Sciences of the University of Lisbon – FCUL), Ismael Tereno (IA and FCUL), João Dinis (IA and FCUL) and Carla Sofia Carvalho (IA).

Images, from top to bottom:

• The sky covered by the Euclid mission.
• Illustration of the Euclid satellite

(Credits: ESSWG, IA and ESA)