Recent research indicates that the streaked slopes on Mars, long suspected to be signs of water flow, are likely not associated with liquid water. TrAC, Adomas Valantinas, Valentin Bickel That’s the question posed by a new holistic study. Using these algorithms to analyze more than 86,000 high-resolution satellite images, they came to the unequivocal support the following conclusion. Follow along as their findings uncover the secrets behind these spectacular phenomena. Since the launch of NASA’s Viking mission first sent back images in the 1970s, scientists have been entranced by them.
These dark, finger-like slope streaks run down the dusty surface of Arabia Terra. These linear features are typically several meters wide, much darker than the surrounding terrain, and run for hundreds of meters in length on inclined surfaces. Many of these streaks run for a year, multiple years, or even 20 or 30 years. Others come and go in short order, leading scientists to designate the shorter-lived features as recurring slope lineae (RSL). Perhaps the most striking feature about the RSL is their highly predictable seasonal patterns. They are always found in the same places, at the hottest times of the Martian “summer.”
Historical Context and Observations
The streaked slopes were only first identified in the 1970s. Even more remarkably, this was all happening at the same time as the very first images returned by NASA’s Viking mission. Ever since, these features have generated a great deal of pioneering interest among planetary scientists and researchers, investigating Mars’ geological and hydrological history. Too often, researchers have looked at these streaks through the wrong lens. Most of these hypotheses center around the idea that they are indicating the presence of liquid water.
Mars is defined by its cold, arid conditions in which it rarely gets above freezing. Here’s what we found that’s most interesting. It indicates that these slope features could actually be due to an entirely different geological process rather than serving as evidence of former water movement. Valantinas emphasized the importance of this research, stating, “A big focus of Mars research is understanding modern-day processes on Mars—including the possibility of liquid water on the surface.”
The bold methodology designed by the researchers opened the door to producing a global map of slope streaks, finding well over 500,000 individual features. Their expansive dataset provided the opportunity to analyze relationships with other environmental factors such as temperature and wind speed.
The Research Methodology
To guide their research, Valantinas and Bickel used advanced machine learning algorithms to analyze a large pool of satellite imagery. This approach gave an extensive, global look at slope streaks on Mars, allowing for a further detailed analysis.
“We could compare it to databases and catalogs of other things like temperature, wind speed, hydration, rock slide activity and other factors,” Bickel noted. This joint effort allowed them to spot trends and begin to understand what sort of conditions produce these geological events.
The findings decisively demonstrated that previous conclusions linking these streaks to the flow of water are not supported. There was zero evidence to back up those claims. Their findings point towards dry formation processes as the main builders of these features. In addition, they are accountable for the movement itself.
Implications for Future Exploration
These findings have major implications as we prepare future Mars exploration missions. Now, scientists can rule out the hypothesis of flowing water behind these streaks. This frees them up to target more efficiently new questions about Mars’ climate history or even current geophysical processes. Valantinas stated, “That’s the advantage of this big data approach. It helps us to rule out some hypotheses from orbit before we send spacecraft to explore.”
The recently released 2018 study underscores the dynamic aspect of these geological features with the potential to move hundreds of millions of tons of dust each year. These processes are key to building an integrated view of Mars’ climate system and how it has changed throughout its history.