Journal List
| ID | 7675 | | Title | International Journal Water Science And Environment Technologies | | E ISSN | 1737-9350 | | P ISSN | 1737-6688 | | Country | Tunisia | | Impact Factor | Awaiting | | Publication year | 2014 | | Publisher Name | Academy | | Frequency | Quarterly | | Indexed | Yes | | Website | http://jistee.org/journal-international-sciences-et-techniques-de-leau-et-de-lenvironnement/ |
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more than 3 million photos of the lunar surface. This week, scientists studying a few hundred of those photos announced what they're calling a "once-in-a-century" discovery: the biggest, freshest impact crater ever seen in the solar system. It's the result of a building-size meteorite that slammed into the moon just two years ago. The new lunar pockmark, named McGetchin crater after the late geologist and lunar scientist Tom McGetchin, is about 728 feet (222 meters) wide, on average, and 141 feet (43 m) deep — imagine a hole as long as two American football fields and deep enough to fit a 14-story building inside. "We know generally that there's more small things in space than there are large things, so that means we tend to get a lot of small craters on the moon and very few large craters," Julie Stopar, a senior scientist at the Lunar and Planetary Institute and deputy principal investigator on the LRO's camera team, told Live Science. "So something the size of this crater, we only expect to encounter that once every 130 years, approximately." McGetchin is nowhere near the moon's largest crater; that honor goes to the South Pole-Aitken basin, a gargantuan gouge about 10,000 times wider than the newly discovered crater. But McGetchin is the largest new crater. Appearing seemingly out of nowhere in images from spring 2024, it's the biggest one scientists have seen in the 17 years that LRO has been active. And now that it's known to the world, some intrepid skywatchers think they've spotted the crater's bright, white debris ring from Earth. The team described their findings in two papers published Sept. 16 in the journal Science Advances. Live Science spoke with Stopar to find out what this fresh crater can teach us about lunar geology, impact rates and potential risks to the future human visitors to the moon. Brandon Specktor: The moon is riddled with craters. What's so interesting about this new one? Julie Stopar: On one hand, it's a nice crater because it's so fresh and new. It hasn't been weathered. On Earth, we see the remnants of impact craters, but a lot of the original details are lost through weathering and degradation and time. But the moon preserves all of that much better. This crater, in particular, is so fresh and young — it's only about 2.5 years old. It's in really, really good condition. We can study it to understand how impact cratering occurs and all the processes that go along with it. The other cool thing is that it impacted on the boundary between two different types of deposits on the moon. There's the volcanic mare deposits [dark patches visible from Earth] and there's the highlands, which are ancient crustal material. The highlands are brighter and tend to be hillier, more mountainous, whereas the mare are flat plains, and they're very dark. This impact seems to have occurred right on the boundary between those two areas, so that's reflected in the materials that are excavated by that crater. BS: The meteorite that made this crater was the size of a three-to-six-story building, according to your team's estimates. Could we have seen this impact from Earth? JS: Yes. This is a relatively large impact, and from Earth, we have observed flashes associated with smaller impacts. So I think it's possible, under good conditions, that this may have made a flash. We don't know if anyone was watching, though — so if somebody out there has videos that they can dig through, they could go back and look for it. A global view of the moon made from hundreds of images taken by the Wide-Angle Camera aboard NASA's Lunar Reconnaissance Orbiter. The black arrow shows the location of McGetchin crater. (Image credit: NASA Lunar Reconnaissance Orbiter)BS: This impact happened in April or May 2024. One of your colleagues discovered the crater in LRO data in October 2025. Why did it take so long? JS: LRO orbits the moon about 12 times each day. While we're going around, we can only image a really small portion of the moon on each pass. So you can imagine it takes many, many orbits to go around the moon and to reimage each part of the surface. When we don't have an impact flash to help us decide where to look for these craters, it's basically a random search. Over time, we eventually will get repeat imaging [of the same area], but it takes years to get that. On top of that, the processing that it takes to make the before and after images takes a lot of work; basically, you're looking through all the images that have been taken of the moon under the right conditions, and it just takes a lot of time and effort to process that. BS: Your colleague, Robert Wagner, says he "stopped and dropped everything" when he discovered the crater in LRO's data. What was your reaction when he first showed it to you? JS: I was surprised that it was so large! But I've seen a lot of similar craters on the moon, so my actual first thought was, "Oh my gosh; this crater might actually help me constrain how old all of these other craters are!" BS: So because you know this crater is so fresh, it's helping you date other craters you've seen too? JS: Yes, I've been looking at a bunch of craters, which I think look morphologically [their shape] and albedo-wise [how much light they reflect into space] very fresh. They have the bright ejecta [the material that gets blasted out from the meteor impact]; they have crisp rims. But I don't know how old they are, because they were there before the LRO. I think they're young, but I don't have any proof of age. So that was my first thought: "Oh my gosh; this makes me feel so much better if all these other craters I'm studying are still in really good condition like this one is." McGetchin crater, circled in white, as seen in a 2025 LRO image (left) compared to an image of the same part of the moon taken in 2011 (right). Scientists think the crater formed between April and May of 2024. (Image credit: NASA Lunar Reconnaissance Orbiter)BS: What, specifically, do you hope to learn about the moon from this crater? JS: There's hope that we can use this to help understand the current impact cratering rate. How much and how often do different sizes of debris in the solar system impact the moon? And that's important, because people want to go to the surface for exploration, send landers, start building moon bases and so forth, and there's some concern that impactors will be a hazard. So it would be helpful to have a better idea of whether that's a really frequent concern or only a once-in-a-while concern. We can also study things like how the impact angle, the target materials, and the velocity and type of impactor play a role in forming craters. This crater will help us better interpret all of the others as well. I think this would be a really good crater to go get samples from, because we know when it formed and we have a lot of questions we can answer with that. Exclusive to Live Science Pro BS: How do you see human-made impacts fitting into this? In recent years, several spacecraft have crashed into the moon. Do you see any risks there or more opportunities to study craters? JS: At this point, it's not too much of a concern to myself about human-made objects destroying natural habitats on the moon. Other spacecraft impacts, like the boosters from the Apollo program, made craters a long time ago. But I think, as there are more people and countries and even companies going to the moon, they'll have to get coordinated so as to not interfere with each other's activities — because that would be a problem. It's just a reminder like, "Hey, guys; you need to talk to each other and get coordinated and make sure you're keeping track of these impacts and your debris, and you're working together." Otherwise, those craters are interesting because we know the impactor's mass and shape beforehand. It gives us a new insight into how craters form when you have irregularly shaped masses, like hollow cylinders and things like that. They'll also tell us about the moon's surface as well, because it's a different type of impact and it's got a different kind of energy to it and a different shape. So we do learn a lot about the cratering process in general from those. This interview has been condensed and edited lightly for clarity. Help us improve Live Science Pro: We're always trying to make our content better. Leave us feedback about Pro here. How much do you know about the moon? Test your lunar smarts with our moon quiz! '> 'Once every 130 years': A huge new crater on the moon could be a giant leap for lunar science, researcher says "We believe this woman was a kind of cast-off after death. She was buried face-down, suggesting a discriminatory attitude," study co-author Qian Wang, a biological anthropologist at Texas A&M University, told Live Science in an email. "Her burial, alone, in a place without her family or community, could be a decision of disapproval." The woman's skeleton was discovered among 300 others in 2019 during an excavation of the Sanzhiyuan cemetery in China's eastern Henan province, according to Wang and colleagues' study, which was published in the November issue of the Journal of Archaeological Science: Reports. She had been buried face down in a wooden coffin on the southern edge of the cemetery, with only a copper hairpin. Radiocarbon dating revealed she lived between 1298 and 1404, which corresponds to either the Yuan dynasty or the early Ming dynasty. But because the original excavation was a rapid salvage dig ahead of construction, the unique skull was not recognized as a possible case of nasal amputation until study first author Yawei Zhou, an archaeologist at Zhengzhou University, analyzed the skeletons from the cemetery in 2024. Several bones inside the nose show signs of healing, indicating that the woman lived for several years after the punishment occurred. (Image credit: Qian Wang, Texas A&M University College of Dentistry)The most obvious indication that the skull was unique was its enlarged piriform aperture, the anatomical term for the nose opening, the researchers wrote in the study. They noticed that the woman's two nasal bones had been partially amputated, leaving only about half of the bridge of her nose. Upon closer examination, they noted that several bones inside the woman's nose had been broken, with signs of healing at the edges. These injuries would have given the middle of the woman's face a "hollow appearance," the researchers wrote. Although they could not completely rule out the possibility that this woman's facial disfigurement was the result of a disease or a birth defect, the researchers concluded that the most likely explanation, particularly in light of her unusual face-down burial position, was a case of nasal amputation as punishment for a crime. "In ancient China's agriculture-based economy, theft of livestock such as cattle and donkey was not uncommon, yet there could be other reasons, such as adultery," Wang said. "At the end of the Yuan Dynasty, such a felony was punished by nasal amputation." Archaeologists know about punitive nasal amputation because it was first recorded in ancient Chinese oracle bone inscriptions. In the Shang dynasty (1600 to 1046 B.C.), the punishment was depicted in Chinese characters as a knife on the left or right side of the nose, the researchers wrote in the study. Examples of the Chinese character for nasal amputation, which includes a knife on the left or right side of the nose. (Image credit: Qian Wang, Texas A&M University College of Dentistry)"I was surprised by this discovery," Wang said, "because so far no scientific report or description of any cases of penal nasal amputation" in archaeological skeletons has been published. But since nasal amputation without anesthesia was one of the "Five Punishments" in early dynastic China — along with tattooing, foot amputation, castration, and death — "there could be many cases in history," Wang said. "People of any walk could be driven to livestock stealing for reasons such as poverty or making quick money." Elizabeth Berger, a bioarchaeologist at the University of California, Riverside who was not involved in the research, told Live Science in an email that the study makes a convincing case for punitive nasal amputation as the cause of the woman's disfigurement. Given this case study, Berger said, "researchers can look for other cases, and hopefully more evidence can be found of who was subjected to this punishment, how it was carried out, and how it was medically managed afterwards, including the use of prosthetics." The unusual skull from the Sanzhiyuan cemetery was assessed within the framework of the Global History of Health Project's Asia Module, which Wang leads. "Many more skeletons will be screened in the future for diseases and trauma," Wang said. "Hopefully there will be similar cases to be found in the future in a clearer archaeological context." '> 700-year-old skull from China is first ever skeletal evidence of nose amputation A patch of bright-white salt at the summit of the Sahara's tallest volcanoWho took the photo? An unnamed astronaut on board the International Space Station When was it taken? Dec. 29, 2024 This intriguing astronaut photo shows a bright-white, salty surprise lurking at the summit of a giant volcano in the Sahara. The ancient, lava-covered peak also holds hidden, shadowy waterways, despite its extremely arid environment. Emi Koussi (also known as Emi Koussou) is a pyroclastic shield volcano in northern Chad. It's located within the Tibesti Massif, a volcanic mountain range that straddles the border between Chad and Libya. The volcano's dome-shaped cone is up to 43 miles (69 kilometers) across and reaches a maximum elevation of 11,204 feet (3,415 meters) above sea level, making it the tallest peak in the Sahara, according to NASA's Earth Observatory. Emi Koussi is classified as extinct, and there are no historical records of it erupting, according to the Smithsonian Institution's Global Volcanism Program. However, scientists know that it was once highly active because its gradual slopes are covered with ancient lava. Some experts think this once-molten rock is around 2 million years old and likely flowed with low viscosity, "more like motor oil than toothpaste," Earth Observatory representatives previously wrote. At the volcano's summit lies a complex caldera system that spans up to 9 miles (15 km) across and is covered with various volcanic vents and cones (see photos below). A second, smaller crater, dubbed Era Kohor, lies at the caldera's southern end. Nestled within Era Kohor, a thick crust of brilliant-white salt covers the lowest part of the caldera's floor. This crystal layer, which reaches up to 3,300 feet (1,000 m) across, reflects light in such a way that astronauts commonly confuse it for snow, which rarely falls in the area. The salty slab within the secondary Era Kohor crater is up to 3,300 feet (1,000 m) across and several feet thick. It was left behind by an ancient lake that once filled the caldera. (Image credit: Stefan Thüngen/wikimedia)The salty compound, known as natron, is a mix of sodium carbonate decahydrate, sodium bicarbonate, sodium chloride and sodium sulfate. It was left behind by an ancient salty lake that once filled Era Kohor but has long since evaporated. This is not the only notable natron deposit in the Tibesti Massif. Around 150 miles (240 km) northwest of Emi Koussi (also in northern Chad) lies a volcanic caldera known as Trou au Natron (or Doon Orei), which contains a layer of the salty substance that is arranged with a pair of cones in a way that makes it look like a giant skull when viewed from above. This unusual deposit lies next to another hefty volcano, dubbed Toussidé, which is also covered with tendrils of ancient lava. While Emi Koussi's ancient activity was mostly centered at its summit, a pair of volcanic cones can be seen on the mountain's northern flank. The lava that quickly flowed from these openings likely helped to create a series of ravines between the mountain and a volcanic plateau, dubbed Tarso Ahon, which is partly visible in the top left of the photo. These ravines are very narrow and deep, meaning they are near-permanently cast in shadow and much cooler than their surroundings. As a result, they can often hold liquid water, despite the Tibesti Massif receiving as little as 0.8 inches (20 millimeters) of rain a year. Two of the largest canyons — which are 2,000 feet (600 m) and 700 feet (250 m) deep, respectively — contain permanent waterways that flow east and west of the volcano, according to the Earth Observatory. False-color satellite images, captured by ESA's Copernicus satellite (main) and NASA's Terra satellite (inset), show off the convoluted topography of Emi Koussi and its summit caldera. (Image credit: Main: ESA/Copernicus Sentinel data (2017); second: NASA/ASTER/GLOVIS)Emi Koussi's slopes are covered with dry "stream channels," which were carved out by millennia of rain flowing down its flanks. Current rainfall patterns would struggle to create such structures. However, thousands of years ago, during the mid-Holocene, the average rainfall was at least 10 times greater, according to a 2025 study that compared the ancient lakes of Era Kohor and Trou au Natron. (The Holocene is the current geological epoch, which began about 11,700 years ago, at the end of the last ice age.) This is not the first time that astronauts have gazed down upon Emi Koussi. In fact, the volcano was one of the first geological formations photographed from space, when the crew of NASA's Apollo 7 mission snapped the imposing peak in October 1968. Libya's 'gold-speckled' lava shadowA stunning composite image, made up of three years' worth of satellite photos, shows the ancient lava of Libya's Haruj volcanic field interspersed with patches of golden sand. Tanzania's 'Mountain of God' loomsA 2020 astronaut photo shows the unique structure of Ol Doinyo Lengai, an active stratovolcano in Tanzania that was recently adorned with a bright white "ash cone." Mauritania's mysterious mesa trioA 2023 astronaut photo shows three dark hills, or mesas, towering above part of the Sahara desert in southern Mauritania. The structures are remnants of a single Paleozoic era formation. '> A surprising slab of salt shines at the summit of the Sahara's tallest peak statement. "These tokens contain complete image information." Collapsing the visual perception processIn conventional visual perception, light signals have to go through multiple stages. A sensor captures the signals, and an analog-to-digital converter turns the light into pixels. That data is then stored temporarily before it's shuttled to a separate chip, where the image is cut into square "compartments" — much like dividing a photo into a grid of tiles. Each compartment is then converted into a token for an AI model to read. One study widely cited by other academics found that an analog-to-digital converter is responsible for 66% of an image sensor's energy consumption, on average. Moving visual data processing off the chip and into the cloud can increase overall energy consumption further. LightTok's solution to the energy problem is to collapse the five stages into one by building the sensing, memory and computation processes into the same pixel. The researchers achieved this through an array based on a technology called a single-layer molybdenum disulfide floating-gate phototransistor that can sense light, remember what it sensed, and then factor that into a calculation. The chip physically eliminates data movement, which is the main source of energy waste. Liang Shi-Jun, physics professor at Nanjing University
Molybdenum disulfide is a 2D material that reacts well to light and can be grown in sheets one atom thick. The phototransistor converts incoming photons — particles of light — into an electrical current, while the floating gate is an isolated component inside the phototransistor that can trap and hold an electrical charge, rather than disappearing after the light goes away. Liang Shi-Jun, a physics professor at Nanjing University, summarized the chip to Chinese state-run news agency Xinhua. "The chip physically eliminates data movement, which is the main source of energy waste," Liang said. "Light comes in, tokens come out" — hence the name "LightTok." LightTok achieved 87.3% accuracy in image recognition during tests — compared to the conventional, multi-step process described above —- while being 10 times more energy efficient at converting light into tokens, the researchers reported in the study. A more efficient physical worldAt present, LightTok's maximum resolution is just 32 by 32 photosensitive pixels — the light-sensitive compartments on an image sensor that capture the visual data. This is far inferior to the quality of current smartphone cameras, let alone drones and autonomous hardware. Nevertheless, Miao said in the statement that there's an opportunity for the technology to be scaled up using the complementary metal-oxide-semiconductor manufacturing process — the same method used to fabricate chips found in smartphones and laptops as well as sensors in drones. The researchers believe that if LightTok can eventually scale successfully, it could transform the operation of remote sensing technology. For example, a drone scanning a disaster zone or remote area could potentially fly longer because less energy is required for visual processing. Kumar Sokka, CEO of Acre Security, a company that provides real-world sensing for critical infrastructure, described the work as a "small-scale demonstration." However, "the direction [of the research] matters to anyone working in the physical world," added Sokka, who was not involved in the new research. Sokka, who previously spent 15 years at industrial automation company Rockwell Automation, told Live Science in an email that too much of the conversation around physical AI has centered around AI models. In truth, the bigger challenge has been the energy cost of "getting what a sensor sees into a form a model can actually use, right where the sensing happens," he said. The massive amount of energy typically required to turn raw data, such as light, into tokens "is wasteful when you're running perception on a robot or an edge device with a tight power budget," Sokka noted. However, processing at the point of detection may be "an enabler for pervasive physical AI, and a clever one, but it's not a cure for the whole problem," he added. Can you match these ancient devices to their pictures? Find out with our computing quiz! '> New LightTok chip converts light directly into 'tokens' for AI — slashing energy use in drones and other autonomous machines 60 million stars: Euclid space telescope snaps the most detailed photo of the Milky Way ever takenAn 'impossible' black hole merger may finally be solved thanks to Einstein's relativity — but it raises an even bigger mystery NASA's latest space telescope has officially taken its first photos of our universe. Launched on Aug. 30, the Nancy Grace Roman Telescope is on its way to Lagrange point L2, a "parking spot" in space about a million miles (1.6 million kilometers) from Earth where it will begin scanning deep space. Using its 300-megapixel camera, Roman captured hundreds of stars as green rings of light. The telescope's Wide Field Instrument hasn't been fully focused yet, which is why these balls of gas appear blurry in the debut test image. But once the instrument is calibrated over the next few months, it should produce images as clear as those taken by the Hubble Space Telescope — but which cover an area 100 times larger. Astronomers hope to use these images to help solve some of the biggest mysteries in our universe, including the possible source of dark energy and the search for alien life. With Roman's first test images now available, what are you most excited about for the future of this space telescope? Answer in the poll below, and let us know your thoughts in the comments! '> What are you most excited for NASA's Roman Space Telescope to find?
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