Hidden Mantle Plume Could Be Nudging Mars to Spin Faster

NASA’s InSight data, compared with Viking measurements, indicate Mars’s day is shortening slightly over time; Delft University researchers propose a buried, buoyant mantle plume—an equatorial negative mass anomaly—that could push lighter material upward while denser material moves downward, speeding Mars’ rotation and potentially triggering volcanism, a finding that points to a more active interior and strengthens the case for a dedicated gravity mission to study Mars’ interior.