Overview

• In a Nature study, researchers report seismic evidence that Mars possesses a small solid inner core encased by a liquid outer core.
• Analysis drew on high signal‑to‑noise marsquake and impact records from NASA’s InSight lander, isolating phases such as PKiKP to identify core structure from a single station.
• The inner core is estimated at about 600 kilometers in radius, likely iron‑nickel with light elements, challenging earlier models that favored a fully liquid core.
• Scientists say the finding carries implications for Mars’ thermal evolution and past dynamo, though details of core composition and shape require further modeling and future seismic networks.
• The result follows separate Science research last week using eight marsquakes to infer kilometer‑scale impact‑derived fragments preserved in the Martian mantle.