Scientists Thought They Had Spotted Flowing Water on Mars. It Turned Out to Be Something Else Entirely.

Yahoo

19-05-2025

Images sent back by NASA's Viking spacecraft in the 1970s revealed some unusual streaks stretching across the arid landscapes of Mars.
The sighting had scientists excited about the possibility of free-flowing water on an otherwise desolate planet. The streaks — which, at times, were thousands of feet long — appeared much darker, contrasting against the mostly monotonal, surrounding hills, looking as if somebody had spilled an enormous glass of water on a patch of hilly sand.
But decades later, we've got copious amounts of new data to rely on, suggesting we were entirely wrong about the features all along. As detailed in a new paper published in the journal Nature Communications, a team of planetary scientists concluded that the streaks didn't have anything to do with flowing water.
"A big focus of Mars research is understanding modern-day processes on Mars — including the possibility of liquid water on the surface," said coauthor and Brown University postdoctoral researcher Adomas Valantinas in a statement. Our study reviewed these features but found no evidence of water. Our model favors dry formation processes."
For decades, the streaks had intrigued scientists, inspiring theories about salt buildups that could allow water to flow on the predominantly dry Martian surface, which only rarely peaks above freezing temperatures. The theory suggested these streaks could therefore be a great place to not only look for Martian life, but possibly inhabit as well.
But new insights have thrown cold water on the idea, if you will. A detailed global Martian map, in particular, revealed over half a million streak features lining the planet's surface, allowing scientists to get a much broader look at the phenomenon.
"Once we had this global map, we could compare it to databases and catalogs of other things like temperature, wind speed, hydration, rock slide activity and other factors," said coauthor and University of Bern researcher Valentin Bickel in a statement. "Then we could look for correlations over hundreds of thousands of cases to better understand the conditions under which these features form."
The researchers found that the streaks were not associated with other factors tied to liquid water or frost, such as slope orientation, surface temperature, or humidity levels.
According to the data, they concluded that the streaks were far more likely to have been formed by high wind speeds and areas with plenty of dust accumulation.
Their theory: the streaks were the result of layers of fine dust suddenly slipping down steep slopes, the result of shockwaves caused by meteorite impacts and marsquakes.
In other words, the streaks aren't a great place to inhabit after all, despite plenty of optimism.
On the other hand, given that microbial life surviving on these slopes is looking extremely unlikely, NASA may be more prone to explore the area with spacecraft since the risk of contamination by an extraterrestrial organism is low.
More on Mars: Astronomers Stunned as Epic Mars Aurora Covers Entire Planet