Marsquake waves reveal the planet’s inner structure
Marsquake waves reveal the planet’s inner structure
A planet’s internal properties and structure can be studied by measuring seismic waves. These waves are caused by processes such as quakes or meteorite impacts. On Mars, the S-waves that emanate from a marsquake (red dot) and are reflected from the core are recorded by the SEIS seismometer on NASA's InSight geophysical station (white dot). By analysing marsquakes, it became possible to better estimate the size of the core (3700 kilometres in diameter), the thickness of the crust (either 20 or just under 40 kilometres) and the structure of the mantle (similar to but simpler than Earth’s upper mantle). In addition, the strength of the reflected waves shows that at least the outer part of the core must be molten as it is impermeable to S-waves.
