Einstein Telescope: Status and perspectives.

Einstein Telescope (ET) is the European project for a third-generation gravitational wave observatory. ET promises to investigate the entire Universe through gravitational wave signals emitted in the coalescences of black holes or neutron stars. ET entered the ESFRI roadmap for future research infrastructures in Europe in 2021, and the ET project and Collaboration have recently been formalised. The exciting scientific goals in astrophysics, nuclear physics, fundamental physics and cosmology will be briefly introduced. The technological challenges for the realisation of the ET observatory will be described, ranging from civil engineering, to the necessary precision mechanics, to new optical and photonic solutions. Finally, the progress of the project and the realisation plan will be presented.