Latest news with #ValentinBickel
The Independent
06-06-2025
- Science
- The Independent
These mysterious dark ‘streaks' on Mars aren't what scientists initially believed
Mysterious dark streaks first observed on Mars in the 1970s are not what many believed they were. Scientists now say the curious features that stretch for hundreds of meters down Martian slopes were likely signs of wind and dust activity — not water. 'A big focus of Mars research is understanding modern-day processes on Mars — including the possibility of liquid water on the surface,' Adomas Valantinas, a postdoctoral researcher at Brown University, said in a statement. 'Our study reviewed these features but found no evidence of water. Our model favors dry formation processes.' Valantinas and the University of Bern's Valentin Bickel coauthored the research which was recently published in the journal Nature Communications. To reach these conclusions, the researchers used a machine learning algorithm to catalog as many of the odd streaks as they could, creating a first-of-its-kind- global Martian map containing some 500,000 from more than 86,000 high-resolution images from NASA's Mars Reconnaissance Orbiter. Then, they compared their map to databases and catalogs of other factors, including temperature, wind speed, hydration, and rock slide activity. They looked for any correlations over hundreds of thousands of cases. The authors found that the ominous streaks that don't last for decades, known as recurring slope lineae or RSLs, are not generally associated with factors that suggest a liquid or frost origin. Those factors might include a specific slope orientation, high surface temperature fluctuations, and high humidity. The features were more likely to form in places with above-average wind speed and dust deposition. That points to a dry origin of formation, and they seem to show up in the same locations during the warmest periods of the Martian year before mysteriously vanishing. They concluded that the older slope streaks, which run down cliff faces and crater walls, most likely form when dust suddenly slides off slopes following seismic activity, winds, or even the shockwaves from meteoroid impacts. The streaks appear most often near recent impact craters, where shockwaves may shake the surface dust loose. The shorter-lived ones are typically found in places where dust devils or rockfalls are frequent. 'There were statistically significant correlations between new impact sites and the appearance of nearby slope streaks in certain regions, supporting this view,' NASA said. Previously, some had interpreted those streaks as liquid flows. It's possible that small amounts of water could mix with enough salt to create a flow on the frozen Martian surface, Brown University noted. The red planet was once more temperate, and there is water under the surface of Mars. Others believed they were triggered by dry process. These results cast new doubt on slope streaks and RSLs as habitable environments. 'That's the advantage of this big data approach,' Valantinas said. 'It helps us to rule out some hypotheses from orbit before we send spacecraft to explore.'
CBS News
20-05-2025
- Science
- CBS News
New study suggests scientists were wrong about dark streaks on Mars
A new study casts doubt on a phenomenon that was previously believed to show water flowing on the surface of Mars. Since the 1970s, scientists have studied dark streaks seen on Mars' cliff sides and crater walls. The streaks tend to be hundreds of meters long. Some can last for a long time, while others are more short-lived. Those more short-lived slope streaks, called recurring slope lineae, or RSLS, tend to recur in the same areas from year to year, according to a news release announcing the study. Some scientists believe the streaks are proof of flowing water on the planet and could suggest the Red Planet is home to habitable environments. Others believe the streaks are caused by dry processes, like rock falls or wind gusts, and said the streaks only appear like liquid remnants because scientists are studying orbital images. Adomas Valantinas, a postdoctoral researcher at Brown University, and Valentin Bickel, a researcher at Switzerland's University of Bern, used machine learning to study the streaks. The process cataloged more than 86,00 high-resolution satellite images of the slope streaks and RSLs. That created a first-of-its-kind global Martian map showing more than half a million such features. Slope streaks extend across Mars' Arabia Terra, as captured by the European Space Agency's Trace Gas Orbiter. NASA "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." Bickel said. "Then we could look for correlations over hundreds of thousands of cases to better understand the conditions under which these features form." The analysis, published in Nature on Monday, found that the slope streaks were not "generally associated with factors that suggest a liquid or frost origin," according to the news release. Such factors would include a specific orientation of slopes, high humidity or surface temperature fluctuations. What the study did find was that the slopes were more likely to form in places that had above-average wind speeds and dust deposition, likely pointing to a dry origin. The slope streaks were more often found near recent-impact craters and could be caused when shockwaves shake surface dust. RSLs are more common in areas with frequent rockfalls or dust devils. "Our study reviewed these features but found no evidence of water. Our model favors dry formation processes," Valantinas said. The results of the study cast doubt on claims that slope streaks could be signs of habitable regions. That means that researchers could send rovers or other spacecraft to explore the areas without contaminating the sites. "That's the advantage of this big data approach," Valantinas said. "It helps us to rule out some hypotheses from orbit before we send spacecraft to explore."
TimesLIVE
20-05-2025
- Science
- TimesLIVE
Study casts doubt on water flows as cause of streaks on Martian slopes
"It's similar to how dry sand can flow like water when poured. But on Mars, the ultra-fine particles and low gravity enhance the fluid-like properties, creating features that might be mistaken for water flows when they're dry material in motion," Valantinas said. The study examined about 87,000 satellite images, including those obtained between 2006 and 2020 by a camera aboard Nasa's Mars Reconnaissance Orbiter, of slope streaks, which form suddenly and fade over years. They average roughly 600m to 775m long, sometimes branching out and going around obstacles. The slope streaks were concentrated mostly in the northern hemisphere, particularly in three major clusters: at the plains of Elysium Planitia, the highlands of Arabia Terra and the vast Tharsis volcanic plateau including the Olympus Mons volcano, towering about three times higher than Mount Everest. The researchers said limitations in the resolution of the satellite images mean they account for only a fraction of slope streaks. They estimated the number at up to two million. Water is considered an essential ingredient for life. Mars billions of years ago was wetter and warmer than it is today. The question remains whether Mars has any liquid water on its surface when temperatures seasonally can edge above the freezing point. It remains possible that small amounts of water, perhaps sourced from buried ice, subsurface aquifers or abnormally humid air, could mix with enough salt in the ground to create a flow even on the frigid Martian surface. That raises the possibility that the slope streaks, if caused by wet conditions, could be habitable niches. "Generally, it is very difficult for liquid water to exist on the Martian surface due to the low temperature and the low atmospheric pressure. But brines, or very salty water, might potentially be able to exist for short periods of time," said planetary geomorphologist and study co-leader Valentin Bickel of the University of Bern in Switzerland. Given the massive volume of images, the researchers employed an advanced machine-learning method, looking for correlations involving temperature patterns, atmospheric dust deposition, meteorite impacts, the nature of the terrain and other factors. The geostatistical analysis found slope streaks often appear in the dustiest regions and correlate with wind patterns, while some form near the sites of fresh impacts and quakes. The researchers also studied shorter-lived features called recurring slope lineae, or RSL, seen primarily in the Martian southern highlands. These grow in the summer and fade the next winter. The data suggested these also were associated with dry processes such as dust devils, or whirlwinds of dust, and rockfalls. The analysis found both types of features were not typically associated with factors indicative of a liquid or frost origin such as high surface temperature fluctuations, high humidity or specific slope orientations. "It all comes back to habitability and the search for life," Bickel said. "If slope streaks and RSL would be driven by liquid water or brines, they could create a niche for life. However, if they are not tied to wet processes, this allows us to focus our attention on other, more promising locations." )
Time of India
19-05-2025
- Science
- Time of India
Study casts doubt on water flows as cause of streaks on Martian slopes
WASHINGTON: Images taken of Mars from orbit dating back as far as the 1970s have captured curious dark streaks running down the sides of cliffs and crater walls that some scientists have construed as possible evidence of flows of liquid water, suggesting that the planet harbours environments suitable for living organisms. A new study casts doubt on that interpretation. Examining about 500,000 of these sinewy features spotted in satellite images, researchers concluded they were created probably through dry processes that left the superficial appearance of liquid flows, underscoring the view of Mars as a desert planet currently inhospitable to life - at least on its surface. The data indicated that formation of these streaks is driven by the accumulation of fine-grain dust from the Martian atmosphere on sloped terrain that is then knocked down the slopes by triggers such as wind gusts, meteorite impacts and marsquakes. "The tiny dust particles can create flow-like patterns without liquid. This phenomenon occurs because extremely fine dust can behave similarly to a liquid when disturbed," said Adomas Valantinas, co-leader of the study published on Monday in the journal Nature Communications. "It's similar to how dry sand can flow like water when poured. But on Mars, the ultra-fine particles and low gravity enhance these fluid-like properties, creating features that might be mistaken for water flows." The study examined about 87,000 satellite images, including those obtained between 2006 and 2020 of slope streaks, which form suddenly and fade over a period of years. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Giao dịch Bitcoin và Ethereum - Không cần ví! IC Markets BẮT ĐẦU NGAY Undo It remains possible that small amounts of water could mix with enough salt in the ground to create a flow even on Mars. That raises the possibility the slope streaks, if caused by wet conditions, could be habitable niches. "It all comes back to habitability... If slope streaks and recurring slope lineae (shorter-lived features) would really be driven by liquid water or brines, they could create a niche for life. However, if they are not tied to wet processes, this allows us to focus our attention on other, more promising locations," said study co-leader Valentin Bickel.
Yahoo
19-05-2025
- Science
- Yahoo
Scientists Thought They Had Spotted Flowing Water on Mars. It Turned Out to Be Something Else Entirely.
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
