NASA's Mars Reconnaissance Orbiter (MRO) has captured a striking image of frozen sand dunes on Mars, located in the planet's northern hemisphere. The photograph, taken in September 2022 by the High-Resolution Imaging Science Experiment (HiRISE) camera and released last month, shows dunes shaped like kidney beans, frozen under a layer of carbon dioxide frost. This discovery could offer new insights into Mars' past climate and whether it could have supported life.

The dunes in the photograph appear motionless, unlike those on Earth, which are constantly shifting. NASA explains that these dunes are covered with a layer of carbon dioxide frost during Mars' winter months. The planet's poles experience extremely low temperatures, reaching -123 degrees Celsius at night, which creates the ideal conditions for both snowfall and frost formation. However, unlike Earth’s snow, Mars experiences two types of snow: water ice and frozen carbon dioxide (dry ice).

The frost, which consists of both water ice and carbon dioxide ice, prevents the wind from carrying the sand, keeping the dunes in place until the spring thaw. Understanding how the frost changes under current conditions can help scientists better predict the planet's past climate.

The search for life on Mars has been a long-standing goal for scientists. In October of the previous year, a NASA study suggested that microbes might be able to survive under the frozen water on Mars' surface. The study found that enough sunlight penetrates the ice to potentially support photosynthesis in shallow pools of meltwater beneath the ice.

Furthermore, a month later, a study from Harvard's Paleomagnetics Lab revealed that Mars' magnetic field, which may have once supported life, could have lasted longer than previously believed. The magnetic field might have extended until 3.9 billion years ago, just 200 million years earlier than previous estimates. This new timeframe overlaps with the period when Mars' surface was covered in water, further suggesting that the Red Planet could have once been a thriving environment for life.