NASA’s Mars Reconnaissance Orbiter (MRO) has captured stunning images of frozen sand dunes, nicknamed ‘kidney beans’, stuck in Mars’ northern hemisphere.
These icy formations, photographed in September 2022 and issued in December 2024, offer directions about the planet’s potential for past life.
Unlike Earth’s ever-changing dunes, Mars’ sand dunes remain motionless during the planet’s northern winter. A layer of carbon dioxide ice covers them, stopping wind-driven sand migration.
As spring approaches and temperatures rise, frost sublimates, allowing the dunes to move again. These frozen features provide scientists with valuable insight into the seasonal changes of Mars and its ancient climate.
Although the frost is made of carbon dioxide rather than water, studying it helps researchers assess whether Mars once had liquid water.
The planet’s axial tilt, which fluctuates significantly over millions of years, drastically changes the climate and seasons.
As Mars tilts more toward the Sun, carbon dioxide ice sublimates extensively, creating a thicker atmosphere. This denser atmosphere could have allowed liquid water to exist for longer periods, possibly supporting microbial life.
The images also highlight the impact of frost cycles on the surface of Mars. By understanding how carbon dioxide frosts form and disappear, researchers can identify geological features linked to past climate changes. These clues provide insight into the history of the Red Planet and its potential habitability.
Periods of stable liquid water in Mars’ past would have increased the chances of life developing there.
Although no direct evidence of life has been found, the continued study of frost-covered dunes and their seasonal changes brings us closer to unraveling the mysteries of Mars. If microbial life ever existed, it could still be hiding in the planet’s subsurface today, waiting to be discovered.
