The discovery of gravitational waves from merging black holes and neutron stars by Advanced LIGO and Advanced Virgo marked the beginning of new era in observing our universe and scientists are keen to fully open up this new window to the (dark side of the) cosmos.

ET will detect several hundred thousand gravitational wave signals per year and allow us listen to the sound of merging black holes across the entire universe. For the first time, researchers will be able to study the precise structure of neutron stars, the birth of black holes and the structure of the universe immediately after the Big Bang.

This third generation of gravitational wave observatories will include several key improvements over the existing facilities: a longer baseline, underground installation and cryogenic suppression of thermal noise. For all these aspects intensive R&D is being undertaken in Europe and beyond.