Mars may be two-faced to its core

Mars, the Red Planet, has long puzzled scientists with its stark contrast between the smooth northern plains and the rugged southern highlands. This difference, known as the crustal dichotomy, has been a subject of debate for decades. A new study published in Nature suggests that this divide is not just a surface feature but extends deep into the planet's interior.

The research, led by Alexander Berne of the University of Arizona's Lunar and Planetary Laboratory, used data from Mars orbiters to analyze the planet's gravitational field. By examining how Mars flexes over its 687-day orbit, the team uncovered evidence of a significant temperature difference between the northern and southern hemispheres. The southern mantle appears to be 200 to 400 degrees Celsius hotter than the northern plains.

This discovery was made possible by a technique called tidal tomography, which allowed scientists to map the planet's internal structure by studying subtle changes in its gravity field. The findings challenge previous assumptions that Mars's interior was uniform, revealing instead a complex, asymmetric structure.

The implications of this discovery are profound. A warmer southern mantle could influence the planet's geological activity and potentially affect its ancient habitability. The study also suggests that the thermal properties of the mantle vary significantly, with the northern region being more rigid and the southern region softer, possibly due to higher temperatures.