What evidence indicates a solid core for Mars, similar to Earth?

Marsquakes provide compelling evidence that Mars has a solid core similar to Earth. The study of marsquakes, or seismic activity on Mars, utilizes seismometers to detect and analyze vibrations caused by tectonic activity. By monitoring these vibrations, scientists can infer the internal structure of the planet, including the presence of a solid core.

The seismic waves generated by marsquakes behave differently depending on the materials they pass through. For instance, if the core were liquid, the seismic waves would not travel through it at all or would be altered in specific ways. The patterns and speeds of the seismic waves detected from marsquakes suggest that Mars has a partially liquid outer core and a solid inner core, which is similar to Earth's internal structure.

Geological surveys might provide valuable information about the surface and geology of Mars, but they do not directly confirm the state of the core. Satellite imagery can offer insight into the planet's topography and surface features but lacks the capability to directly assess the core's properties. Sample return missions, while potentially rich in data about surface materials, would not directly provide evidence about the planetary core unless specific measurements or analyses were conducted in relation to seismic activity.