ESA’s Euclid mission is on a quest to unveil the nature of two elusive ‘dark’ entities. As the renowned theoretical physicist Stephen Hawking remarked in 2013, “The missing link in cosmology is the nature of dark matter and dark energy”.

During the last 70 years, scientists have made enormous progress in understanding the very initial phases of the Universe and its evolution to the present day. Thanks to advances in observations and theoretical modelling, a clear picture has emerged of how stars form, and how galaxies grow and interact with each other, coming together to form groups and clusters.

Yet, fundamental mysteries remain. 95% of the Universe appears to be made up of unknown ‘dark’ matter and energy. Dark matter and energy affect the motion and distribution of visible sources but do not emit, reflect or absorb any light. And scientists do not know what these dark entities actually are.


To address this question, Euclid will create a great map of the large-scale structure of the Universe across space and time by observing with unprecedented accuracy billions of galaxies out to 10 billion light-years. This is not easy, and making sure that Euclid is up to the task has required the expertise and dedication of many people over several years of work.

This video captures the journey behind the Euclid mission, from a human and intensely visual perspective. It shows tiny screws, winding cables and shiny surfaces in a whole new light, revealing how each piece comes together to form the space telescope. Be drawn in by awe-inspiring photos of the cosmos, and stay for the seemingly choreographed ballet of teamwork necessary to assemble and test the spacecraft, before being swept away by the emotion of the launch into space.

Euclid’s adventure has begun. With its observations during the coming years, it will help us uncover the missing link in cosmology and open the gate to the ‘dark’ side of the Universe.