By placing a single seismic station on Mars, InSight tries to address a fundamental issue of planetary and Solar System science: understanding the processes that shaped the rocky planets of the inner Solar System (that include Earth) more than four billion years ago. InSight’s primary objective is to study the earliest evolutionary history of the processes that shaped Mars. By studying the size, thickness, density and overall structure of Mars' core, mantle and crust, as well as the rate at which heat escapes from the planet's interior, InSight will provide a glimpse into the evolutionary processes of all of the rocky planets in the inner Solar System.
The mission will determine if there is any seismic activity, the amount of heat flow from the interior, the size of Mars' core and whether the core is liquid or solid. The mission's secondary objective is to conduct an in-depth study of geophysics, tectonic activity and meteorite impacts on Mars, which could provide knowledge about such processes on Earth.
In terms of fundamental processes shaping planetary formation, Mars is a ‘goldilocks’ planet - it contains the most in-depth and accurate historical record, because it is big enough to have undergone the earliest processes that shaped the terrestrial planets, but small enough to have retained the signature of those processes.