After the launch of Euclid: 'This is a big step toward understanding dark matter and dark energy'

What is it like to work on the fundamental questions about the universe? On July 1, the Euclid satellite launched successfully. This mission from the European Space Agency will take images of the sky to create the most detailed map of the universe ever made. Astronomer Henk Hoekstra (Leiden Observatory) and physicist Alessandra Silvestri (Leiden Institute of Physics) tell about their role in the mission.