Scientists Uncover Clues About Mars’ Past in Mysterious Hills

Research team analyzes thousands of Martian hills, revealing new insights into the planet’s history.

London – The mysteries of Mars continue to captivate scientists, prompting extensive research to unravel its secrets. Space probes and NASA rovers have been exploring the Red Planet for years, and soon, the European Space Agency (ESA) will join the effort with its own rover, Rosalind Franklin. In preparation for its landing, researchers have closely examined the designated landing region, uncovering fascinating details about Mars’ past.

Near the Chryse Planitia region, at the boundary between Mars’ two hemispheres, lies a vast field of thousands of hills. Just south of this area is the Martian dichotomy, a long-standing geological mystery that another research team recently claimed to have solved. According to Joe McNeil from the Natural History Museum in London, these hills represent a “prime location for future Mars missions.”

Martian Hills Provide Clues to Planet’s History

McNeil and his team have conducted an in-depth analysis of these hills using images from NASA and ESA. Their findings reveal that each hill consists of layered deposits, with the oldest rocks at the base dating back approximately four billion years. “For a geologist, examining these layers is like reading the pages of a book—each one tells a unique story,” McNeil explained.

One of the most significant discoveries is the presence of up to 350 meters of clay-rich rock within the hills. This suggests that Mars once had abundant surface water for an extended period, potentially supporting the controversial theory of an ancient northern ocean. “Our research indicates that Mars’ climate in the distant past was dramatically different,” McNeil stated. The clay minerals in Chryse Planitia point to the existence of large quantities of liquid water nearly four billion years ago.

Unraveling Mars’ Geological Timeline

Despite these compelling discoveries, determining the precise age of the hills remains challenging since scientists cannot directly analyze their material. Instead, they estimate age by counting impact craters—areas with more craters are generally older than those with fewer. McNeil’s team estimates that the formation of these hills may have taken between 100 and 200 million years.

ESA’s Rosalind Franklin rover, whose launch was delayed due to geopolitical tensions, could provide further insights. With NASA’s support, the rover is now expected to launch in 2028. Once on Mars, it will conduct extensive exploration, including drilling up to two meters below the surface, potentially offering unprecedented details about Mars’ geological history and its potential to have once hosted life.

The research findings were published on January 20, 2025, in the journal Nature Geoscience.