Mars 2020 may be NASA’s most ambitious mission to that planet yet. One of its goals is to initiate a multi-step process that eventually leads to the return of a sample of Mars back to Earth. In order to decide which samples the mission will bring home, the rover will have an instrument called SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals). This instrument requires calibration to ensure precise and accurate measurements and for that they have come up with something special. They are going to send the meteorite Sayh al Uhaymir 008 (SaU008), which is a martian rock. After a long explosive journey from the surface of Mars, through space to Earth, this rock is finally going home.