ESA’s Euclid mission has reached a new milestone in its development with successful testing of the telescope and instruments showing that it can operate and achieve the required performance in the extreme environment of space.

Euclid will study dark energy and dark matter. Whilst these cannot be seen directly by any telescope, their presence and influence can be inferred by observing the large scale distribution of galaxies in the universe.

It has long been known that the universe is expanding as measurements of distant galaxies show them moving away from us. The expansion, along with the growth of cosmic structures such as galaxy superclusters, are influenced by dark energy and dark matter, but scientists don’t fully understand these phenomena yet.