Latest news with #ValentinBickel
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
Yahoo
12-02-2025
- Science
- Yahoo
Mars Is Rocked by Epic Quakes, And They Don't All Come From Within
Incredibly powerful marsquakes that violently shake the red planet don't always begin under the surface, research shows. A new study using artificial intelligence to analyze seismic data reveals just how strongly and deeply quakes rattle around the red planet's interior – a finding that has implications for our understanding of the gooey Martian core, and how worlds like Earth, Mars, and Venus form. The research also shows that many more rocks smack into Mars than previously thought, which changes how we must think about what Mars has going on beneath its dusty surface. "Our observations show that some of the recorded marsquakes are actually caused by meteoroid impacts and not tectonic activity," explains planetary scientist Valentin Bickel of the University of Bern in Switzerland. "This has far-reaching implications for estimates of the frequency of marsquakes and our understanding of the dynamics of the Martian surface in general." Although Mars is the second-most thoroughly studied planet in the Solar System (after Earth), there's so much we don't know about its dynamics, its history, and its evolution. Our data is limited to what we can sense from afar, after sending machines millions of kilometers across the Solar System to beam data back home. One such machine was the Mars InSight lander, a seismometer station active between 2018 and 2022, designed to detect the activity rumbling away beneath the Martian surface. Scientists had thought Mars was pretty close to geologically dead, so imagine their surprise when InSight detected more than 1,300 quakes during its deployment. Quakes on Mars can either start from inside the planet, from geological or magmatic activity, or occur as the result of an impact from an incoming space rock. Scientists have even been able to link tremors detected by InSight to fresh craters. Bickel and his colleagues used a machine learning algorithm to look for impact craters that newly appeared during InSight's tenure. They examined images of the Mars surface in that time, collected during ongoing observations by the HiRISE instrument on the Mars Reconnaissance Orbiter. They then cross-referenced the 123 new craters they found with the seismic recordings from InSight, and tried to find matches in space and time. They were able to correlate 49 seismic events to at least one impact event each. "Our data show that more impacts occur on Mars than were determined in previous studies using orbital images," Bickel says. In fact, the new estimated rate of significant impacts on Mars is 1.6 to 2.5 times higher than previous estimates. Mars, with its tenuous atmosphere, takes an absolute pummeling. In a second, complementary paper, the researchers zoomed in on one of the impacts, a 21.5-meter (70.5-foot) impact crater near Cerberus Fossae, a region in a young volcanic plain rife with seismic activity. The team was able to link this crater to a specific, high-frequency marsquake – which means scientists may need to rethink their previous interpretation of Cerberus Fossae. "We thought Cerberus Fossae produced lots of high-frequency seismic signals associated with internally generated quakes, but this suggests some of the activity does not originate there and could actually be from impacts instead," explains planetary scientist Constantinos Charalambous of Imperial College London. The researchers also studied the quake data collected by InSight to learn more about how impacts affect Mars. Their analysis showed that impact-generated seismic waves were not, as previously thought, confined to Mars' outer layer, the planetary crust. Rather, they were able to penetrate into and below the mantle via a 'seismic highway', reaching more distant regions of the planet. Once again, this suggests that rethinking is in order. The way seismic waves propagate through a body can be used to map the different densities of the materials they travel through. Misunderstanding that seismic propagation means that the interior of Mars was likely mischaracterized. "These findings challenge previous assumptions about the propagation of seismic waves and suggest that numerous recorded marsquakes were actually further away from the Mars lander InSight than previously thought," Charalambous says. "In addition to relocating the epicenters of a range of quakes, this also means that the internal structural model of Mars needs to be revised." The two papers have been published in Geophysical Research Letters. They can be found here and here. Scientists Reveal an Ambitious Plan to Detect Dark Matter in Space Odds of a Tunguska-Scale Impact in 2032 Just Doubled Deep Chasms Could Lead to a Hidden Ocean on Uranus's Moon Ariel
