Could Marsquakes finally help scientists solve the 50-year mystery of Mars' surface?

Martian surface (Image: Canva)

A puzzle about Mars has intrigued scientists for decades. The planet’s two hemispheres are strikingly different in structure. New research may have uncovered why these differences exist.

Unveiling the Martian Dichotomy

Mars’ northern lowlands sit 5-6 kilometres below the southern highlands. The crust in the north is significantly thinner than in the south. Scientists call this stark contrast the "Martian dichotomy." This feature has been studied since NASA’s Viking orbiter captured images in the 1970s.

A recent study published in Geophysical Research Letters suggests the divide may stem from internal heat transfer. Earlier theories proposed cosmic collisions as a cause. Researchers used data from NASA’s InSight lander to support their findings. Marsquake data provided clues about the planet's internal structure and dynamics.

Mars’ surface shows a striking contrast in elevation between its northern and southern hemispheres, a phenomenon known as the Martian dichotomy. (Image: NASA)

The study highlights that Mars once had tectonic plate movement. Shifting plates and molten rock beneath them likely caused the divide. This process stopped when the tectonic plates formed a "stagnant lid" over the molten interior.

Heat and Mantle Convection Shaped Mars

The findings suggest mantle convection shaped Mars’ crust over time. Heat rising from the interior altered the planet’s surface billions of years ago. Geochemical analysis of Martian meteorites further supports this theory. These meteorites revealed details about Mars’ thermal history and composition.

The southern highlands are ancient, heavily cratered, and magnetised. They date back to when Mars had a magnetic field. In contrast, the northern lowlands are younger, smoother, and lack magnetisation.

The study offers a significant step in understanding Mars’ history. However, researchers stress the need for more marsquake data. Comparative studies could further validate the theory and explain the planet’s evolution.