Gravity maps of Mars reveal strange structures hidden beneath the surface

Scientists unveiled a unique gravity map of Mars at the 2024 European Planetary Science Congress. The map reveals important structures beneath Mars’ ancient ocean and highlights how mantle processes affect Olympus Mons, the largest volcano in the solar system. The study used data from NASA’s InSIGHT (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission and small satellite deviations.

Reassessing Martian geology

The forthcoming paper, “Mars’ global gravity field reveals an active interior,” led by Bart Rutter of TU Delft and published in Universe Today, challenges existing geological theories. It questions the concept of flexo-isostasis, which traditionally describes how a planet’s lithosphere (including the crust and upper mantle) responds to large-scale loading.

On Earth, this loading would normally cause the lithosphere to buckle downward, with the surrounding area rising slightly. However, Mars’ Tharsis Mons, a vast volcanic region, contradicts this model. Rather than sinking, Tharsis Mons is clearly rising.

Hidden Features of Mars

According to Science Express, researchers believe that active processes within the Martian mantle are pushing the Tharsis Mountains upward. They found a massive rock body about 1,750 kilometers wide and 1,100 kilometers deep, likely a mantle plume, exerting enough force to offset the downward pressure of the rock body in the volcanic region.

In addition, the study also discovered dense and mysterious structures beneath the north polar plains of Mars. These anomalous structures are buried under smooth sediment layers and have a density of about 300-400 kg/m3 higher than the surrounding environment. Although similar structures on Earth’s moon are associated with impact basins, the anomalous structures in the northern hemisphere of Mars do not show such surface traces.

Future Exploration Plans

To further investigate these mysterious structures and Mars’ gravity, researchers are advocating for the Mars Quantum Gravity (MaQuls) mission. Dr. Lisa Wörner of the German Aerospace Center (DLR), who presented the mission at EPSC2024, explained that MaQuls would employ techniques similar to those used in the GRAIL and GRACE missions. This mission could provide a deeper understanding of Mars’ subsurface features and ongoing mantle convection, improving our understanding of dynamic processes on Mars.