A research team led by University of Chicago planetary scientist Edwin Kite has proposed a new model of Mars' climate evolution, revealing the mechanism by which Mars experienced brief periods of liquid water followed by rapid desertification. The study, published in Nature, uses carbonate-rich rocks discovered this April by NASA's Curiosity rover as key evidence to explain the thinning of Mars' atmosphere and its dramatic climate transitions.

"Our model suggests that Mars' habitable period was the exception, not the norm," said Kite, a participating scientist on the Curiosity mission. Mars and Earth are both rocky planets with similar compositions, yet today Mars' surface is covered with canyon systems and ancient lakebeds, indicating it once had a warm climate and liquid water. According to the research, Mars' liquid-water period was triggered by increasing solar luminosity, but as Martian volcanic activity gradually waned, carbon cycling became unbalanced. Carbon dioxide was permanently locked into rocks, ultimately driving irreversible desertification. "Unlike Earth's continuous carbon cycle, Mars' volcanic dormancy disrupted the balance between CO₂ release and sequestration," Kite explained.

This discovery was made possible by Curiosity's detection of carbonate rocks on Mount Sharp. Scientists had long been puzzled about the fate of carbon in the Martian atmosphere; the new model confirms that CO₂ absorption into rocks is the primary explanation. Co-author Benjamin Tutolo, a professor at the University of Calgary, emphasized: "The chemical and mineralogical data provided by the rover are essential for understanding planetary habitability." Through extensive modeling, the team demonstrated that Mars' climate alternated between short intervals of liquid water and desert periods lasting as long as 100 million years—conditions highly unfavorable for the sustained evolution of life.