NASA’s InSight mission first measured Mars’s interior using seismic activity.
InSight landed in Elysium Planitia on 26 November 2018. Its principal instrument, the Seismic Experiment for Interior Structure, or SEIS, detected marsquakes and vibrations caused by meteorite impacts. Scientists used those signals to infer the boundaries and properties of Mars’s crust, mantle, and core.
The mission provided the first direct seismic measurements from another planet besides Earth. Its data showed that Mars has a liquid core and helped refine estimates of the thickness and layering of the Martian crust.
InSight also carried a heat-flow probe called the Heat and Physical Properties Package. The probe could not reach its intended depth because the soil did not provide the expected resistance, but the mission still achieved its central geophysical goals. InSight’s mission ended in December 2022 after dust reduced power from its solar panels.