Seismic waves suggest Mars has a solid heart

The purported solid inner core has a radius of about 600 kilometers

Illustration of NASA's InSight lander sitting on Mars' surface with instruments deployed.

From late 2018 to late 2022, NASA’s InSight lander (illustrated) detected seismic waves on Mars to probe the Red Planet’s interior.

NASA/JPL-Caltech

Mars may have a hardened heart.