Scientists observed seismic waves traveling through Mars’ core for the first time and confirmed model predictions of the core’s composition. The researchers used seismic data acquired by the NASA InSight lander to directly measure properties of Mars’s core, finding a completely liquid iron-alloy core with high percentages of sulphur and oxygen ( Proceedings of the National Academy of Sciences).
To determine these differences, the team tracked the progression of two distant seismic events on Mars, one caused by a marsquake and the other by a large impact, and detected waves that travelled through the planet’s core. By comparing the time taken by the waves to travel through Mars compared with waves that stayed in the mantle, and combining this information with other seismic and geophysical measurements, the team estimated the density and compressibility of the material the waves travelled through, as per a release.
The researchers’ results indicated that Mars most likely has a completely liquid core, unlike Earth’s combination of a liquid outer core and solid inner core.