Overview

• A Science paper published on Aug. 28 reports compositionally distinct lumps up to about 4 kilometers wide scattered within Mars’ mantle.
• Researchers examined eight marsquakes from InSight’s 2018–2022 archive, including events triggered by recent meteorite impacts that left craters about 150 meters across.
• Higher-frequency seismic waves arrived late and showed interference, a pattern reproduced in models with embedded debris from ancient giant impacts.
• Lead author Constantinos Charalambous, with colleague Tom Pike, attributes the fragments’ survival to Mars’ sluggish interior circulation and lack of plate tectonics.
• The mix of large shards and many smaller pieces aligns with a violent early impact history and informs how rocky planets assembled and evolved.