Surprising temperature difference in the depths of Mars: Southern hemisphere could be up to 400 degrees hotter

Beneath the surface of Mars, it has been determined that there may be a much larger temperature difference than expected between the planet's two hemispheres. According to a new study published in Nature, the interior regions of the southern hemisphere of Mars are approximately 200 to 400 degrees Celsius hotter than the northern hemisphere.

Scientists do not yet know for certain why this difference, described as "thermal asymmetry," occurs. However, the finding suggests that the internal structure of Mars may be more complex than previously thought and holds important clues regarding the planet's early evolution.

The distinct differences between the northern and southern hemispheres of Mars have been known for a long time. While the southern hemisphere has a higher, heavily cratered, and geologically older surface, the northern hemisphere is lower, flatter, and covered with vast plains. Planetary scientists call this distinction the "Martian hemispheric dichotomy."

The new study shows that this duality may not be limited to surface features but could extend deep into the planet's interior. The study's lead author, planetary scientist Alexander Berne from the University of Arizona, notes that planetary interiors are often assumed to be symmetric on a global scale, but the case of Mars reveals that this may not always be the case.

HOW IS THE TEMPERATURE DIFFERENCE EXPLAINED?

Researchers are focusing on several possibilities to explain why the mantle in the south appears to be hotter. One of these is that a massive impact that occurred early in Mars' history may have caused heat in the northern hemisphere to be lost more rapidly.

Another possibility is regional convection movements that took place in the mantle in the past. The rising of hot material within the planet and the sinking of colder material may have created persistent temperature differences in different regions over a long period.

The study also evaluates that the thick and high crust in the south of Mars may have acted as insulation for billions of years, making it difficult for heat from the mantle to escape into space. This scenario stands out as one of the possible explanations for why the temperature in the southern hemisphere may have been preserved for a longer time.

The thermal anomaly may also be important for questions regarding Mars' ancient magnetic field. Today, Mars does not have a global magnetic field like Earth; however, strong magnetic traces are found in ancient rocks in the southern hemisphere. The fact that the southern mantle was hotter in the past suggests that geological and magnetic processes in this region may have operated differently than in the north.

The findings could also contribute to debates about how long Mars remained warm in the past and how long it could sustain conditions that might harbor liquid water. A better understanding of the planet's internal heat distribution could help explain processes such as volcanism, the evolution of the atmosphere, and the persistence of liquid water on the surface.

Researchers state that more detailed data on Mars' gravitational field could contribute to mapping the planet's internal structure in three dimensions. This data is seen as critical to understanding whether the hot mantle region in the south is linked to Mars' early environmental conditions.