The aim of the Planet MARS project is to investigate and characterize the nature of Mars’ interior structure and dynamics using a broad range of observations as well as theoretical, numerical, and experimental approaches. This ETH-funded project builds upon the successful landing and acquisition of data from the NASA Mars InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander. InSight is the first robotic explorer to study crust, mantle, and core of Mars with the goal of answering key questions about the early formation of the inner solar system rocky planets and rocky exoplanets. InSight also measures tectonic activity and meteorite impacts on Mars today. Considering the scale and breadth of the scientific challenge, Planet MARS proposes an integrated, fully comprehensive approach joining exploration geophysicists, geodynamicists, experimental petrologists, mineral physicists, volcanologists, geochemists, and numerical and observational seismologists in a unique collaborative framework.