At the forefront of this research is planetary geologist Steven Banham from Imperial College London, who, alongside a dedicated team, identified unique sedimentary structures captured by NASA’s Curiosity rover. These structures, known as supercritical climbing wind ripples, are distinctive millimeter-thick laminations formed by the rapid movement of sand grains under intense, sustained winds. Unlike typical dune or ripple formations caused by seasonal winds or long-term climate patterns, these ripples are signatures of severe, short-duration windstorms—sandstorms that lasted only minutes to hours—a phenomenon previously undocumented on Mars.

The significance of these findings lies in the rarity and nature of the sedimentary deposit. On Earth, wind ripple strata like these are seldom observed because they require very specific conditions of wind velocity and sediment availability to form and be preserved in the rock record. Their discovery on Mars is unprecedented and represents the first definitive proof that the Red Planet once experienced windstorms of considerable intensity. Until now, while it was accepted that Mars had an atmosphere capable of generating wind, direct evidence of such extreme meteorological events had eluded scientists.

The Curiosity rover’s imaging systems played a pivotal role in this discovery. The team first noticed anomalies in black-and-white panoramic images obtained at the end of one of Curiosity’s drives. These features piqued their curiosity, prompting them to employ higher-resolution color cameras, including the MASTCAM, for detailed examination. This targeted imaging revealed intricate ripple patterns with supercritical climbing geometries—structures indicative of sand grains moving in a highly dynamic environment, where sand avalanching and migration occur simultaneously under powerful gusts.

The presence of such wind ripple strata also carries critical implications for the ancient Martian atmosphere. Current modeling and measurements indicate that today’s atmosphere on Mars is too thin to generate winds strong enough to transport and deposit sand on this scale. Therefore, the newly discovered ripples implicate a past atmosphere denser than today’s, potentially approaching conditions more akin to early terrestrial environments. This denser atmosphere would have had a profound impact on climate, weather, and the potential habitability of Mars during the period when water activity was pronounced.

Furthermore, the timing of this event is crucial, occurring roughly 3.6 billion years ago—a window when Mars was transitioning from a wetter and potentially life-supporting world to the cold, dry planet we observe now. The sandstorm’s occurrence provides context for understanding shifts in atmospheric density, composition, and surface interactions during this transformative era. It paints a vivid picture of episodic, extreme weather phenomena playing a role in shaping the Martian landscape and its sedimentary record.

Banham emphasizes the almost cinematic nature of this occurrence: envisioning a sudden, turbulent sandstorm sweeping across Gale crater, generating these exquisite ripple deposits and leaving behind a momentary record in the geological record. The notion that such ephemeral events, lasting mere hours and fleeting in the planet’s deep time history, can now be reconstructed with such clarity through rover instruments is truly remarkable.

The serendipity involved in this discovery adds an intriguing narrative layer to the findings. Rather than a planned investigation, it was by chance and sharp observation that Banham and his colleagues identified these unusual formations. This underscores the importance of real-time analysis and the diverse expertise of the scientific teams operating Mars rovers, who continuously monitor countless images and data streams for subtle clues about the planet’s past.

Looking forward, the team hopes this discovery will catalyze further explorations into Mars’ sedimentary structures and atmospheric history. One particularly enticing prospect is the search for rain impact marks—physical evidence of precipitation on Mars’ surface. While there is abundant indirect evidence for ancient water flows, like riverbeds and lake sediments, direct traces of rainfall impacts remain elusive. Their identification would dramatically advance our understanding of Martian hydrology and climate cycles.

This revelation also carries vital implications for planetary science and astrobiology. Understanding the dynamic ancient weather conditions helps constrain models of atmospheric evolution and surface habitability. Although the sandstorm evidence does not directly prove past life on Mars, it enriches our understanding of environmental variables that would have influenced potential habitable niches and the preservation of biosignatures.

The research is meticulously documented in the journal Geology, providing a technical framework for interpreting these supercritical climbing wind ripple strata. The work not only highlights the versatility and power of the Curiosity rover but also the synergy between engineering marvels and scientific inquiry in remote planetary environments.

In sum, the documentation of a supercritical climbing wind ripple sandstorm in Gale crater serves as a testament to Mars’ once-active and complex environment, offering a glimpse into the meteorological forces that sculpted its surface billions of years ago. This discovery exemplifies the spirit of exploration and the continual rewriting of planetary history as new evidence is unearthed from the Martian terrain.

Subject of Research: Ancient sandstorm evidence on Mars through sedimentary wind ripple structures

Article Title: An ancient sandstorm recorded by supercritical climbing wind ripple strata in Gale crater, Mars

News Publication Date: 2026

Web References:

• DOI link: http://dx.doi.org/10.1130/G54158.1

References:
Banham, S., et al., 2026, An ancient sandstorm recorded by supercritical climbing wind ripple strata in Gale crater, Mars; Geology.

Image Credits:
NASA/JPL-Caltech/MSSS

Keywords

Mars, Gale crater, Curiosity rover, supercritical climbing wind ripples, sandstorm, sedimentary structures, ancient atmosphere, Martian climate, planetary geology, wind erosion, sediment transport, extraterrestrial weather phenomena

For decades, slope streaks on Mars have puzzled planetary geologists. These features, typically tens to hundreds of meters long, are transient and periodically reform over years to decades. Previously, speculations about their formation oscillated between theories of liquid water activity, dry granular flows, or even biological processes. However, the complete absence of definitive evidence for liquid water in many slope streak regions cast doubt on aqueous mechanisms, and biological explanations remain speculative. Bickel’s study, through an innovative combination of high-resolution imagery and computational modeling, firmly positions aeolian—wind-driven—processes as the fundamental cause of these phenomena.

The cornerstone of Bickel’s research is the detailed examination of Martian dust and sand behavior under the planet’s current atmospheric conditions. Mars’ thin atmosphere, composed predominantly of carbon dioxide, is capable of generating wind speeds sufficient to mobilize fine particles across the surface. These suspended particles aggregate into dust devils, storms, and persistent local winds that can dislodge and transport sediment materials. The interaction between wind-entrained dust and the gravity-affected sandy materials on slopes initiates a feedback mechanism, leading to localized slope destabilization and the visible streak formation.

High-resolution images obtained from the Mars Reconnaissance Orbiter’s HiRISE camera have been pivotal. By meticulously cataloging streak formation over multiple Martian years, Bickel and colleagues demonstrated recurring patterns correlating with seasonal wind variations. During peak winds, loose dust is mobilized, cascading downslope and stripping away superficial bright dust layers to reveal darker underlying material. This contrast generates the visually striking streaks detected from orbit. Notably, the morphology of these streaks—often elongated with bifurcated end points—matches the expected trajectories of particles channeled and re-deposited by turbulent wind flows.

The study further advances the conceptual framework by integrating digital terrain modeling with experimental wind tunnel data. Simulations recreate the Martian atmospheric conditions and replicate the movement of sands and dust on slope angles ranging between 10 and 30 degrees, typical for observed slope streak locations. These models confirm that granular avalanches are triggered when wind shear stresses exceed threshold values, which are modulated by particle size, cohesion, and slope inclination. Crucially, this avalanche process occurs without requiring any liquid phase, disproving earlier hypotheses that transient briny flows might be responsible.

Bickel’s findings also touch on the broader implications for Mars’ surface evolution. Slope streak formation serves as an active indicator of modern erosional and sedimentary processes, challenging the assumption that Mars is wholly geologically static in the present epoch. Instead, these granular flow events highlight ongoing surface modification driven by atmospheric dynamics, underscoring a more vibrant and active Mars than previously thought. The interaction between wind and sediment not only reshapes slopes but also contributes to dust redistribution across vast regions, influencing climate and visibility conditions on the surface.

An unexpected revelation from the research is the temporal variability of slope streak activity. By correlating streak prevalence with Mars’ seasonal atmospheric cycles, the team uncovered that streak formation is most vigorous during southern hemisphere summer, coinciding with the peak of dust storm events and elevated wind speeds. This seasonal pulse governs the availability of dust and the intensity of surface winds, thereby acting as a natural schedule for surface remodeling. The findings imply that Mars undergoes rhythmic environmental changes influencing geomorphological features on a decadal scale.

The research also clarifies that not all slope streaks are homogenous in their genesis. Variations in local topography, sediment composition, and dust availability produce subtle differences in streak morphology and longevity. For instance, streaks in equatorial regions often display sharper boundaries and longer persistence, possibly due to lower atmospheric moisture and unique wind patterns. Conversely, streaks near polar latitudes are more ephemeral, disrupted by sublimation cycles and seasonal frost deposits. Such spatial heterogeneity highlights the delicate balance between physical processes and planetary conditions governing streak formation.

Crucially, Bickel’s work impacts the search for extant water-related features on Mars, a central theme in planetary exploration. By attributing slope streaks to dry physical mechanisms, the research narrows the potential locations and conditions under which liquid water might be active today. Although water-ice sublimation and vapor exchange continue to play vital roles at high latitudes, phenomena like streaks now appear disconnected from those processes. This demarcation aids mission planning by directing surface investigations towards more promising sites for water or biosignature detection.

Moreover, understanding wind-driven slope streaks contributes to mission safety and operational planning for robotic explorers. Dust accumulation and deposition patterns affect solar panel efficiency and instrumentation performance. Knowledge of surface material mobilization can help predict and mitigate risks associated with dust storms and sediment movements. Future rover missions could also exploit slope streaks as natural laboratories to monitor sediment transport dynamics and atmospheric-surface interactions in situ.

Bickel’s study is exemplary for its multidisciplinary approach, blending observational data from orbiters with theoretical physics and laboratory-based experimentation. This synergy enhances confidence in the interpretations and elevates the standard for planetary geomorphological research. The robust evidence presented pushes the frontier of Martian science by unifying disparate datasets into a coherent model of active surface processes governed by environmental forces rather than exotic mechanisms.

The implications of this research extend beyond Mars. Comparative planetology benefits from insights into aeolian geomorphology under low-pressure, cold conditions—parallels observable on bodies like Titan or Pluto. Understanding how dust and sand flows generate visible changes informs theories about landscape evolution across the solar system, enriching our comprehension of planetary atmospheres, surface geology, and climate feedback loops.

Looking ahead, the study invites further exploration using advanced remote sensing technologies. Continued monitoring of slope streaks over successive Martian years could illuminate long-term environmental trends and rare episodic events. Integration with atmospheric modeling to predict dust storm genesis and movement may refine our knowledge of Mars’ climate system. In addition, sample return missions targeting streak-affected terrains might reveal compositional clues vital for unraveling the material properties influencing these granular flows.

In sum, the investigation by V.T. Bickel marks a pivotal milestone in Martian research by identifying dust, sand, and wind as the principal architects of slope streaks. This discovery dismantles long-held conjectures centered on liquid water and unveils the complexity of Mars’ surface-atmosphere interactions. It redefines our perception of Mars as a dynamically evolving world, sculpted not only by ancient water flows and volcanic forces but also by the persistent whisper of its thin, gusting atmosphere. As we continue to decipher Mars’ mysteries, this study stands as a testament to the power of integrated science in unlocking the secrets etched into the Red Planet’s rugged slopes.

Subject of Research: Martian slope streak formation mechanisms driven by dust, sand, and wind.

Article Title: Dust, sand and wind drive slope streaks on Mars.

Article References:
Bickel, V.T. Dust, sand and wind drive slope streaks on Mars. Nat Commun 16, 9583 (2025). https://doi.org/10.1038/s41467-025-65522-4

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41467-025-65522-4

Mars has long fascinated researchers with its dramatic topography, including towering volcanoes and vast craters, but it is the deceptively simple dust devil phenomena that now offer critical insights into the planet’s atmospheric processes. These swirling columns of dust act as natural tracers, rendering visible the otherwise invisible winds that sweep across Mars’s surface. The novel research led by Valentin Bickel and his team at the University of Bern, Switzerland, harnessed the power of artificial neural networks to analyze more than twenty years of high-resolution images from ESA spacecraft, identifying 1039 individual dust devils and tracking speeds and directions for 373 of them. This data not only confirms the widespread distribution of dust devils but also highlights ‘source regions’—areas such as Amazonis Planitia—that act as prolific generators of dust devils due to their fine dust and sand coverage.

The critical breakthrough enabling these measurements lies in a subtle artifact of the imaging sequence design. Both Mars Express and ExoMars TGO capture images through multiple spectral channels with small inter-channel delays ranging from mere seconds to nearly a minute. Movements of dust devils during these interludes create distinct ‘colour shifts’ or offsets in composite images—initially considered image noise—that the researchers ingeniously exploited to calculate velocities. By quantifying these shifts across sequential color or stereo image channels, the team achieved detailed assessments of dust devil displacement, velocity, wobble, and acceleration, allowing an unprecedented global analysis of Martian wind speeds indirectly measured from orbit.

One of the most striking revelations is that the wind speeds driving these dust devils exceed model predictions significantly. In some regions where the dust devils traveled fastest, winds outpaced the expectations of existing Mars atmospheric models, suggesting that current models underestimate the capacity for dust entrainment and transport. This factor has consequential effects on the planet’s climate system, as dust influences surface temperatures by both shading the surface during the day and insulating it at night, modifies cloud formation by providing nucleation sites, and contributes to the gradual loss of water vapor through dust storm-mediated escape processes.

Seasonal and diurnal trends observed in the data mirror those on Earth, with dust devils most abundant during local spring and summer times in each hemisphere. These vortices typically arise in the late morning to early afternoon hours, peaking between approximately 11:00 and 14:00 local solar time. Their transient nature, lasting only minutes, combined with their spatial distribution, adds crucial layers of complexity to the Martian dust cycle. Understanding when and where dust devils form sharpens the predictive models that inform both climate science and mission operations for Mars exploration.

The comprehensive dust devil catalogue is a public resource, setting the stage for widespread scientific engagement beyond this initial study. Continuous image acquisition by Mars Express and ExoMars TGO promises a growing database that can refine wind and dust models further. The strategic coordination of simultaneous imaging across missions aims to validate measurements and cross-check velocity estimates, enhancing accuracy. These efforts underscore a transformative approach to planetary atmospheric science, leveraging serendipitous imaging characteristics and machine learning for insights beyond original mission goals.

Moreover, the enhanced understanding of near-surface wind conditions holds pragmatic value for the planning and operation of future Mars missions. Wind patterns directly influence the deposition of dust on solar panels, impacting energy generation and operational longevity of rovers. For example, ESA’s ExoMars Rosalind Franklin rover is scheduled to land in 2030 during dust storm-quiet seasons, factoring in these refined wind and dust dynamics. Insights into local wind regimes also inform landing site selection and spacecraft design, providing real-world constraints on dust accumulation and abrasive erosion risks.

Unlike Earth, where rain efficiently clears dust particles from the atmosphere, Mars’s near-vacuum environment allows dust to remain aloft for extended periods, circulating planet-wide. This persistent dustiness plays a foundational role in atmospheric thermal balance and weather patterns, making the study of dust devils more than an exercise in curiosity—it is central to Mars climatology. By tracking these ephemeral dust devils, scientists have acquired a rare dataset illuminating the intricate processes that control one of Mars’s most influential climatic drivers: dust lifting and transport.

In an era where planetary exploration increasingly relies on synergy between orbital platforms and surface assets, this research epitomizes how indirect observations from high above revolutionize our understanding of planetary environments. The methodology of transforming image artifacts into scientific data exemplifies innovative reuse of mission datasets, enabling unprecedented insights without altering spacecraft hardware or operations. Dust devils, once merely nuisances for imagery and instruments, now emerge as exquisite natural wind tracers, exposing the invisible forces shaping the Martian surface and atmosphere.

Finally, the success of this study reinforces the paradigm that multidisciplinary approaches—combining remote sensing, artificial intelligence, and atmospheric science—can unveil novel phenomena and reshape longstanding assumptions about planetary climates. As Mars Express and ExoMars TGO continue to collect images daily, the catalogue will expand, fostering new research avenues exploring dust dynamics, weather forecasting, and landing risk assessments. This continuous flow of data propels humankind ever closer to safely navigating and ultimately understanding the enigmatic and weather-beaten Red Planet.

Subject of Research:
Article Title: Dust Devil Migration Patterns Reveal Strong Near-surface Winds across Mars
News Publication Date: 8 October 2025
Web References: https://doi.org/10.1126/sciadv.adw5170
References: Bickel et al., Science Advances, 2025, DOI: 10.1126/sciadv.adw5170
Image Credits: ExoMars TGO data: ESA/TGO/CaSSIS; Mars Express data: ESA/DLR/FU Berlin; Background: NASA Viking colour mosaic
Keywords: Mars, dust devils, Mars Express, ExoMars Trace Gas Orbiter, near-surface winds, atmospheric dynamics, wind speed measurements, neural network, climate modeling, dust transport, planetary exploration