A groundbreaking analysis of two decades of orbital imagery has revealed that Martian winds are far more ferocious than previously understood. By tracking the ghostly trails of tornado-like dust devils, scientists have created the first global map of surface winds on Mars, discovering that these whirlwinds can race across the rusty landscape at speeds rivaling a Category 1 hurricane on Earth. The findings overhaul long-standing models of the planet’s atmosphere and have significant implications for understanding its climate and ensuring the safety of future missions.
The new research, published in Science Advances, details how a catalogue of over 1,000 dust devils was used to clock near-surface wind speeds up to 158 kilometers per hour (98 mph). This dramatically exceeds previous estimates from climate models and limited rover measurements, which had suggested maximum speeds closer to 100 km/h. By leveraging a clever new technique to analyze archival images from European Space Agency (ESA) orbiters, the science team has provided a new, dynamic picture of Mars as a world where powerful winds actively reshape the environment, lifting far more dust than scientists had accounted for. This work is crucial for predicting weather patterns and identifying safe landing sites for upcoming robotic and human exploration.
A New Era of Martian Meteorology
For years, scientists have relied on limited, localized data to understand Martian weather. Rovers and landers provided invaluable ground truth but could only measure conditions at their specific locations. Orbital observations of cloud movements offered clues about higher-altitude winds, but the winds whipping across the surface remained largely invisible and unmapped on a global scale. This study marks a pivotal shift by systematically charting these surface winds across the entire planet for the first time.
The breakthrough came from making the invisible visible. The study’s lead author, Valentin Bickel of the University of Bern, noted that dust devils serve as natural tracers for the wind. By tracking their movement, the team could directly measure the speed and direction of the winds driving them. This approach transforms our understanding from a patchwork of isolated measurements into a comprehensive, planet-wide view of atmospheric dynamics at the surface, revealing a world more active and energetic than prior models had suggested.
Turning Noise into Data
The foundation of this research was an immense archive of images collected over 20 years by two ESA spacecraft: the Mars Express, which has been orbiting the planet since 2004, and the ExoMars Trace Gas Orbiter (TGO), which arrived in 2016. Manually searching this vast dataset would have been impossible. Instead, the team trained a neural network, a form of artificial intelligence, to automatically scan the images and identify the faint, swirling tracks characteristic of dust devils. This automated process allowed them to build a robust catalogue of 1,039 separate events.
The truly innovative step was how the researchers calculated their speed. The cameras on the orbiters capture images in different color channels with a delay of a few seconds between each shot. For a static landscape, these channels align perfectly. However, for a moving object like a dust devil, the delay causes a slight color separation or “offset” in the final composite image. What was once considered an imaging glitch or digital noise became the key signal. By measuring this offset, the scientists could precisely calculate how far the dust devil traveled between color exposures and, therefore, its exact speed and direction.
Revising the Models of a Dusty Planet
The results of the mapping project were startling. The study recorded wind speeds reaching up to 44 meters per second, or 158 km/h. While Mars’s atmosphere is extremely thin—only about 1% the density of Earth’s—meaning a person would barely feel such a gust, these speeds are more than capable of lifting and transporting large quantities of dust. The previous scientific consensus, based on global circulation models, had not predicted such powerful, widespread winds at the surface.
This discrepancy has profound implications for the Martian dust cycle, which is a critical driver of the planet’s climate. Dust in the atmosphere absorbs solar radiation, which in turn heats the air and influences temperature. It can act as a shield to cool the surface during the day and as a blanket to retain heat at night. The finding that winds are much stronger than assumed suggests that models have been significantly underestimating the amount of dust being lofted from the surface. This newly identified dust load will require climate scientists to refine their models to better reflect the planet’s energy balance and atmospheric behavior.
Mapping Seasonal and Daily Patterns
The comprehensive new catalogue not only revealed wind speeds but also confirmed and expanded our understanding of where and when dust devils form. The map shows that while these whirlwinds can appear almost anywhere on Mars, including on its towering volcanoes, they are most heavily concentrated in specific “source regions.” One of the most active areas is Amazonis Planitia, a vast, flat plain covered in a deep layer of fine sand and dust.
The data also reinforces a distinct seasonal and daily cycle for dust devil activity, which mirrors patterns seen in arid regions on Earth. Activity surges during the spring and summer in each hemisphere, when the ground is heated most intensely by the sun. They are a daytime phenomenon, typically forming in the late morning and reaching their peak frequency and intensity between 11:00 and 14:00 local Martian solar time. This is the period when the temperature difference between the warm ground and the cooler air above is greatest, providing the convective energy needed to spawn the vortices.
Implications for Future Exploration
A more accurate understanding of Martian wind and dust activity is not just an academic exercise; it is a critical safety and engineering concern for future missions. The powerful gusts now known to exist could pose risks to spacecraft during landing and to hardware on the surface. Dust is a notorious challenge on Mars, capable of coating solar panels, infiltrating mechanical joints, and creating visibility hazards.
By providing a detailed forecast of wind and dust activity, this research will be invaluable for mission planners. Engineers and scientists can use these new maps to select safer landing sites in regions with calmer weather and to design more resilient equipment capable of withstanding the harsh, dynamic environment. The public catalogue of dust devils created by the study will serve as a foundational resource for years to come, enabling deeper analysis of Martian weather patterns and helping to ensure the success of humanity’s next steps on the Red Planet.
