Einstein Telescope, the future generation of ground based gravitational wave detectors

The second-generation gravitational wave detectors Advanced LIGO and Advanced Virgo have shown their breakthrough capability to shed light on our understanding of the Universe. Although the steady increase in sensitivity, these detectors will hit in the future limitations due to their hosting infrastructures. This is the reason why a new generation of gravitational wave detectors are under studies. The Einstein Telescope (ET) is a planned European 3rd generation gravitational Wave (GW) Observatory, a new research infrastructure designed to host a detector capable to observe the entire Universe using gravitational waves. ET will be a multi-interferometer observatory aiming to increase a factor ten the sensitivity of previous generation detectors. We will give an overview of the project, describe the main scientific goals and the technological challenges that must be overcome to reach the expected sensitivity.