Mars-quakes provide insight into the secrets of the planet's inner core

Embargoed until: Publicly released: 2025-09-04 01:00

International

Photo by Planet Volumes on Unsplash

Mars likely has a solid inner core, according to analysis of data from NASA's InSight lander. The team looked at seismic data collected from the surface of Mars, finding that the seismic waves travelled faster through the inner core than would be expected if it were entirely liquid, suggesting that there is a solid element. According to the authors, further calculations suggest that the radius of this inner core is about 600 kilometres. A better understanding of the inner core of Mars could help scientists understand the evolution of Mars' magnetic field, as well as the magnetic fields of other planets in the solar system.

Media release

From: Springer Nature

Planetary science: Seismic detection of a solid Martian inner core (N&V) *IMAGE*

Evidence for a solid inner core in Mars, detected by NASA’s InSight mission, is presented in a study published in Nature this week. This finding furthers our understanding of the properties and evolution of both Mars and similar planetary bodies.

The inner core of Mars is known to be at least partially liquid, with theoretical work suggesting the feasibility of a solid component to the core. However, previous studies have been unable to confirm whether any part of the core is solid.

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.

Multimedia

Comparison between the interior structures of Earth and Mars

Journal/
conference: Nature

Research:Paper

Organisation/s: University of Science and Technology of China, China

Funder: We thank D. J. Stevenson for his insights and discussions, which have improved this study. We thank N. Schmerr, M. Panning and two anonymous reviewers for their comments, which have improved the manuscript from both methodological and scientific perspectives. We thank Q. Huang for providing the SKS_GD and SKS_GP inversion models, and X. Song, B. Chao and H.-Y. Yang for comments on the paper. We acknowledge the National Aeronautics and Space Administration (NASA), Centre National d’Études Spatiales (CNES), their partner agencies and institutions (UK Space Agency (UKSA), Swiss Space Office (SSO), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Jet Propulsion Laboratory (JPL), Institut de Physique du Globe de Paris–Centre National de la Recherche Scientifique (IPGP-CNRS), Eidgenössische Technische Hochschule Zürich (ETHZ), Imperial College London and Max Planck Institute for Solar System Research–Max-Planck-Gesellschaft (MPS-MPG)) and the flight operations team at JPL, SEIS on Mars Operations Center (SISMOC), Mars SEIS Data Service (MSDS), Incorporated Research Institutions for Seismology Data Management Center (IRISDMC) and Planetary Data System (PDS) for providing SEED SEIS data. We appreciate the Supercomputing Center of the University of Science and Technology of China (USTC) for high-performance computing services. This research was supported by the B-type Strategic Priority Program of the Chinese Academy of Sciences, grant XDB41000000; the National Natural Science Foundation of China 42241117, 42394113 and 41722401.

Media Contact/s

Contact details are only visible to registered journalists.