Latest news with #UniversityofBern
Gizmodo
7 hours ago
- Science
- Gizmodo
Something Big Is Twisting Mercury's Crust
Mercury has it rough. Not only is it the smallest planet in the solar system, it's also the closest to our Sun. This unfortunate position has caused Mercury to develop cracks and fractures across its surface, and generate stresses to its crust, a new study has found. Mercury is dry, rugged, and heavily cratered; the planet appears deformed with towering cliffs and ridges, as well as fracture lines that run along its surface. The origin of Mercury's scars has long been a mystery: How did the planet cool and contract in such an unusual way billions of years ago after it formed? Turns out, the answer may be due to its uncomfortable proximity to the Sun. A team of researchers from the University of Bern created physical models of Mercury to see how much of the Sun's tidal forces affect the small planet, revealing that the star may have influenced the development and orientation of tectonic features on its surface over long periods of time. The results are detailed in a study published in the Journal of Geophysical Research: Planets. Planets form from the hot, molten material left over from the birth of a star. Over time, these objects cool and their internal materials shrink, causing them to contract as their crusts wrinkle and crack. Evidence has shown that Mercury, on the other hand, not only shrank—its surface also shifted laterally. Cracks and fractures also formed in its rocky crust. Scientists assumed that the process that shaped Mercury's outer layer was a result of this cooling and contracting, but the study suggests it may be the planet's cozy orbit around the Sun. Mercury has one of the most unique orbits in the solar system. It takes about 88 Earth days to complete one orbit around the Sun, during which the planet rotates around its axis three times every two orbits. Its orbit is also highly elliptical and is tilted by around 7 degrees compared to Earth's orbital plane, its eccentricity means that the tidal forces Mercury experiences from the Sun vary a lot. 'These orbital characteristics create tidal stresses that may leave a mark on the planet's surface,' Liliane Burkhard, a researcher at the Space Research and Planetary Sciences Division at the Institute of Physics at the University of Bern, and lead author of the study, said in a statement. 'We can see tectonic patterns on Mercury that suggest more is going on than just global cooling and contraction.' The team behind the study sought to investigate how these tidal forces contribute to shaping Mercury's crust. They used physical models of Mercury over the past 4 billion years to calculate how the Sun's tidal forces may have influenced its surface tensions. The results showed that the the changing gravitational pull of the Sun has impacted Mercury's tectonic features over time. 'Tidal stresses have been largely overlooked until now, as they were considered to be too small to play a significant role,' Burkhard said. 'Our results show that while the magnitude of these stresses is not sufficient to generate faulting alone, the direction of the tidally induced shear stresses are consistent with the observed orientations of fault-slip patterns on Mercury's surface.' The recent findings can also be applied to other planets, illustrating how subtle forces aside from tectonics can make a lasting impact on its surface. 'Understanding how a planet like Mercury deforms helps us understand how planetary bodies evolve over billions of years,' according to Burkhard. The scientists behind the new study are hoping to gather more clues about Mercury's deformed surface through the BepiColombo mission, which launched in October 2018 as a joint venture between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). BepiColombo is only the third spacecraft to visit Mercury; the elusive planet is hard to reach due to the Sun's powerful gravitational pull that may have maimed the planet's surface.
South China Morning Post
5 days ago
- Science
- South China Morning Post
China's Yellow River will be choked by ice jams due to global warming, study finds
Ice jams will become more frequent in the Yellow River's estuary by the end of this century, hitting Chinese coastal cities such as those in eastern Shandong province, according to a new study. Advertisement When warmer weather arrives in late winter and early spring, upstream ice begins to break apart and drift downstream. This ice then reaches colder downstream areas, where it can refreeze and accumulate, forming ice jams. The localised hazard can be highly destructive. Flooding can occur behind the blockage, while a sudden ice jam collapse can release a torrent of ice and water, damaging downstream communities , wildlife and infrastructure. 'By integrating historical records with climate projections, we provide compelling evidence that climate warming is not only driving a long-term decline in ice jam flood frequency but also shifting the geographic distribution of hotspots downstream,' the scientists wrote. Researchers from Jiangsu Normal University, the Chinese Academy of Sciences and the University of Bern in Switzerland published their findings – based on analysis of the dynamics of ice jam floods in the lower Yellow River over the past 160 years – in the peer-reviewed journal Science Advances last week. Advertisement The Yellow River is the second-longest river in China and the sixth-longest in the world. While it is considered the cradle of Chinese civilisation, the river is also called 'China's Sorrow' for its history of devastating floods that took millions of lives in the last two centuries.
Forbes
12-06-2025
- Science
- Forbes
AI Will Provide Much Needed Shortcut In Finding Earthlike Exoplanets
In the search for earthlike planets, AI is playing more and more of a role. But first one must define what is meant by earthlike. That's not an easy definition and is the cause of much confusion in the mainstream media. When planetary scientists say that a planet is earthlike, they really mean it's an earth mass planet that lies in the so-called habitable zone of any given extrasolar planetary system. That's loosely defined as the zone in which a given planet can harbor liquid water at its surface. But there's no guarantee that it has oceans, beaches, fauna, flora, or anything approaching life. Yet Jeanne Davoult, a French astrophysicist at the German Aerospace Center (DLR) in Berlin, is at the vanguard of using artificial intelligence to speed up the process of finding earthlike planets using AI modeling and algorithms that would boggle the minds of mere mortals. In a recent paper, appearing in the journal Astronomy & Astrophysics, Davoult, the paper's lead author writes that the aim is to use AI to predict which stars are most likely to host an earthlike planet. The goal is use AI to avoid blind searches, minimize detection times, and thus maximize the number of detections, she and colleagues at the University of Bern write. Using a previous study on correlations between the presence of an earthlike planet and the properties of its system, we trained an AI Random Forest, a machine learning algorithm, to recognize and classify systems as 'hosting an earthlike planet' or 'not hosting an earthlike planet,' the authors write. For planetary detection, we try to identify patterns in data sets, and patterns which correspond to planets, Davoult tells me via telephone. Understanding and anticipating where earthlike planets form first, and thus targeting observations to avoid blind searches, minimizes the average observation time for detecting an earthlike planets and maximizes the number of detections, the authors write. But among the estimated 6000 exoplanets thus detected in the last 30 years, only some 20 systems with at least one earthlike planet have been found, says Davoult. In fact, stars smaller than the Sun --- such as K-spectral type dwarfs as well as the ubiquitous red dwarf M-spectral type stars which make up most of the stars in the cosmos, all have longer lifetimes than our own G-spectral type star. Thus, because of their long stellar lifetimes, it's probably more likely for intelligent life to develop around these K and M types of stars, says Davoult. We are also focusing a lot on M dwarfs because it's easier to detect an earthlike planet around the stars than around sun like stars, because the habitable zone is closer to the stars, so the orbital period is shorter, she says. The three populations of synthetic systems used in this study differ only in the mass of the central star, the authors write. This single difference directly influences the mass of the protoplanetary disk and thus the amount of material available for planet formation, note the authors. As a result, the three populations exhibit different occurrences and properties for the same type of planet, highlighting the importance of studying various types of stars, they write. We have developed a model using a Random Forest Classifier to predict which known planetary systems are most likely to host an earthlike planet, the authors write. It's hard to really compare synthetic planetary populations and real planetary populations, because we know that our model is not perfect, says Davoult. But if you just take the big pattern at the system level, then I'm convinced it's a very powerful tool, she says. If we observe a planet within a given solar system, it doesn't mean that we've detected all the planets in this planetary system, says Davoult. That's because an earthlike planet might be a bit too far away from the star, or too small to detect, she says. In contrast, my model takes what we already know about planetary system and tells us if there is a possibility for an undetected earthlike planet to exist in the same planetary system, says Davoult. Davoult is specifically looking for terrestrial planets in the habitable zone of their parent stars. The very first step is just to detect them and create a database of earthlike planets, even if we have no clue about the composition of their atmospheres, says Davoult.
Yahoo
06-06-2025
- Science
- Yahoo
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.'
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." )
