Mars-quakes provide insight into the secrets of the planet’s inner core
Evidence for a solid inner core in Mars, detected by NASA’s InSight mission, is presented in a study published in Nature. It furthers our understanding of the properties and evolution of both Mars and similar planetary bodies.
Daoyuan Sun and colleagues used seismic data obtained from NASA’s InSight mission to investigate the structure of the Martian inner core.
The measurements suggest the presence of two seismic phases: PKKP – the deep core-transiting phase – and PKiKP, a reflected seismic phase used to indicate the presence of a solid inner core – as previously demonstrated for the Earth and Moon.
The seismic waves from the PKKP phase arrived at the seismometer on the Insight Lander between 50 to 200 seconds earlier than would be expected if the core were purely liquid, suggesting a solid element to the core structure. Further calculations based on these figures allow the authors to constrain the radius of this inner core to about 600 kilometres.
This finding provides direct evidence of a solid inner core on Mars and offers insights into the evolution of the red planet.