Satellite explores mysteries of the dark Universe

A European mission to explore how dark energy and dark matter shaped the evolution of our Universe has soared into space.

Edinburgh astronomers have played a key role in preparing the satellite – known as Euclid – for its six-year space exploration that could revolutionise scientists’ understanding of the cosmos.

From its final position one million miles from earth, Euclid’s powerful two-tonne telescope will examine around 1.5 billion galaxies, across one third of the sky – creating the largest and most accurate 3D map of the Universe ever produced.

The mission will also gather specific scientific data that researchers will use in attempts to solve two of the biggest mysteries in the Universe: dark matter and dark energy.

Dark forces

Unlike normal matter, dark matter does not reflect or emit light. However, it is thought to make up around 80 per cent of all the mass in the Universe and binds galaxies together.

Dark energy is a mysterious new phenomenon that is pushing galaxies away from each other and causing the expansion of the Universe to accelerate. It appears to drive cosmic objects apart at an increasingly rapid rate rather than drawing them together as gravity does, experts say.

International mission

Led by the European Space Agency and a consortium of 2,000 scientists from 16 countries, Euclid will use two scientific instruments to carry out its research.

A UK-built optical imager (VIS), one of the largest cameras sent into space and capable of measuring gravitational lensing distortions, and a near infrared spectrometer and camera, developed in France.  

Research focus

Astronomers from the Institute for Astronomy at the School of Physics and Astronomy will lead on two key research areas including Euclid’s gravitational lensing data analysis. Gravitational lensing produces minute changes in the images of galaxies which can be used to map out the distribution of dark matter in space and how it has evolved over cosmic time.

Edinburgh is also hosting Euclid’s UK Science Data Centre, which will process huge amounts of data gathered throughout the mission for teams of scientists worldwide.

Rocket launch

Euclid took off on board a SpaceX Falcon 9 rocket from Cape Canaveral in Florida at 4.12pm (BST) on 1 July.

As well as aiming to answer some of science's most fundamental questions about the nature of the Universe, Euclid is set to revolutionise studies across all astronomy – providing a lasting legacy and database for professional astronomers and the public to explore.

Professor Andy Taylor from the School’s Institute for Astronomy, who leads the gravitational lensing data analysis for Euclid, said:

This is a very exciting time for astronomy, and cosmology in particular. Euclid is designed to answer some of the biggest questions we have about the Universe. It has been a lot of hard work by many scientists to get here, but the results could change how we understand Nature.

Dr Alex Hall, from the School’s Institute for Astronomy, and deputy lead of the Gravitational Lensing Science Working Group, said:

With the launch of Euclid begins an astronomical observing campaign that is amongst the most ambitious ever attempted. By imaging over a billion galaxies, Euclid will allow us to make a map of dark matter with unprecedented precision that will answer fundamental questions about our Universe. The next few years are going to be very exciting, and it is a privilege to be part of this incredible project.

Professor Alkistis Pourtsidou from the School’s Institute for Astronomy, who leads the team for Euclid’s nonlinear modelling, said:

Euclid is going to provide a very large and very detailed 3D map of the Universe- across the sky and along time. This map in itself is a remarkable achievement combining state-of-the-art science and engineering. We want to extract the maximum amount of information from it, and use it to figure out how Nature works at the most fundamental level.