Inner core of Mars is similar to that of Earth: Study
Scientists have confirmed that Mars has a solid inner core, similar to Earth's. Professors Sun Daoyuan and Mao Zhu's team used seismic data from NASA's InSight lander and found the core is about 600 km across. It has been found that the inner core primarily consists of a tough iron-nickel mix with some sulfur, oxygen, and carbon thrown in.