NASA's Curiosity rover has discovered signs of seasonal floods on Mars at a site called Gale Crater. Ars Technica reports: About 3,000 Martian days into its exploration, the rover was at a site that dates to roughly 3.6 billion years ago, during Mars' relatively wet Hesperian period. And it came across what would be familiar to gamers as a hex grid: hundreds of hexagonal shaped rock deposits in the area of a few centimeters across and at least 10 centimeters deep. These features are small enough that they'd be easy to overlook as simply another collection of wind-swept debris on the red planet. But up close, they're striking: large collections of hexagons that share sides, creating a regular grid. While there's some irregularity, the lines separating them largely form three-way intersections with equal angles between each line. And, in places where erosion has had different effects on nearby instances, it's clear that individual hexagons are at least 10 centimeters in height.

Similar shapes have been seen on Pluto, formed by convection of an icy surface. But these are far, far larger, able to be detected from a considerable distance from Pluto. The tiny size of the hexes on Mars is completely incompatible with convection. Instead, it has to be the product of mud drying out, creating cracks as the material contracts. The water itself could either come externally, in the form of a flood, or via groundwater that soaks up to the surface. But again, the tiny size of these features is decisive, indicating that only the top few centimeters got wet, which is incompatible with a groundwater source. To form the regular, hexagonal shapes also means repeated cycles -- experiments show that at least a dozen cycles are needed before you start to get the equal angles at the junction.

So, simply based on their shape, it appears that these hexagons are the product of repeated flooding. The chemistry backs this up. The rocks in the lines that separate individual hexagons are largely a mixture of calcium and magnesium sulfates, which will readily precipitate out of water as conditions get drier. These deposits will form harder rocks than the dried mud that comprises the bulk of the hexagons. The researchers behind the work note that the apparently regular, mild wet/dry cycling is incompatible with a lot of ideas about the source of water in Mars' past, such as volcanic melting of ice deposits. Instead, it's consistent with mild seasonal flooding, although there's no way to tell if the cadence was tied to Mars' orbit given what we currently know. The findings have been published in the journal Nature.

An anonymous reader quotes a report from the BBC: Scientists near Chicago say they may be getting closer to discovering the existence of a new force of nature. They have found more evidence that sub-atomic particles, called muons, are not behaving in the way predicted by the current theory of sub-atomic physics. Scientists believe that an unknown force could be acting on the muons. More data will be needed to confirm these results, but if they are verified, it could mark the beginning of a revolution in physics.

All of the forces we experience every day can be reduced to just four categories: gravity, electromagnetism, the strong force and the weak force. These four fundamental forces govern how all the objects and particles in the Universe interact with each other. The findings have been made at a US particle accelerator facility called Fermilab. They build on results announced in 2021 in which the Fermilab team first suggested the possibility of a fifth force of nature. Since then, the research team has gathered more data and reduced the uncertainty of their measurements by a factor of two, according to Dr Brendan Casey, a senior scientist at Fermilab. "We're really probing new territory. We're determining the (measurements) at a better precision than it has ever been seen before."

In an experiment with the catchy name 'g minus two (g-2)' the researchers accelerate the sub-atomic particles called muons around a 50-foot-diameter ring, where they are circulated about 1,000 times at nearly the speed of light. The researchers found that they might be behaving in a way that can't be explained by the current theory, which is called the Standard Model, because of the influence of a new force of nature. Although the evidence is strong, the Fermilab team hasn't yet got conclusive proof. They had hoped to have it by now, but uncertainties in what the standard model says the amount of wobbling in muons should be, has increased, because of developments in theoretical physics. In essence, the goal posts have been moved for the experimental physicists. The researchers believe that they will have the data they need, and that the theoretical uncertainty will have narrowed in two years' time sufficiently for them to get their goal. That said, a rival team at Europe's Large Hadron Collider (LHC) are hoping to get there first. The results have been announced to the public and submitted to the Journal Physical Review Letters.

Extreme "glacial cooling" that occurred more than a million years ago in southern Europe is likely to have caused an "extinction of early humans" on the continent, according to new research. From a report: The previously unknown ice age pushed the European climate to "beyond what archaic humans could tolerate" and likely wiped out human life on the continent temporarily, concluded an academic paper published in the journal Science. The findings by 11 researchers from institutions including University College London and the University of Cambridge challenge the long-held idea that humans have continuously occupied Europe since first arriving in the region.

The newly discovered cooling event was "comparable to some of the most severe events of recent ice ages," said the paper's lead author Vasiliki Margari from UCL. "We suggest that these extreme conditions led to the depopulation of Europe," the researchers concluded. Glacial-interglacial cycles, or warmer and colder periods each lasting thousands of years, have occurred cyclically over the past 2.6mn years, with large ice sheets forming during the colder spells and melting during the warmer periods. According to the academic paper, a previously unknown glacial period that occurred about 1.1mn years ago led to abrupt cooling that lasted about 4,000 years. This happened as conditions began to warm and large ice sheets melted into the Atlantic Ocean, which pushed down European sea and land temperatures.

An anonymous reader quotes a report from The Guardian: Virgin Galactic's VSS Unity, the reusable rocket-powered space plane carrying the company's first crew of tourists to space, successfully launched and landed on Thursday. The mission, known as Galactic 02, took off shortly after 11am ET from Spaceport America in New Mexico. Aboard the spacecraft were six individuals total -- the space plane's commander and former Nasa astronaut CJ Sturckow, the pilot Kelly Latimer, as well as Beth Moses, Virgin Galactic's chief astronaut instructor who trained the crew before to the flight. The spacecraft also carried three private passengers, including the health and wellness coach Keisha Schahaff and her 18-year-old daughter, Anastasia Mayers, both of whom are Antiguan. [...]

Galactic 02 is a suborbital flight. However, despite VSS Unity not reaching orbit, the trajectory allows passengers to experience several minutes of weightlessness at an altitude high enough for them to see the Earth's curvature, Space.com explains. Following liftoff, Virgin Galactic's carrier plane VMS Eve transported VSS Unity to an altitude of about 44,300ft. Eve then dropped Unity which then fired its own rocket motor and ascended to suborbital space. Passengers aboard experienced approximately 3Gs. Live footage inside the spacecraft showed the passengers unstrapping themselves from their seats and peering out down to earth through the windows as they floated throughout the spacecraft.

Despite Galactic 02 being Virgin Galactic's second commercial spaceflight mission, it is the first flight to carry private customers. In June, Galactic 01 carried three crew members from the Italian air force and the National Research Council of Italy. According to Virgin Galactic, the company has already booked a backlog of about 800 customers. Tickets have ranged from $250,000 to $450,000. Galactic 03, the company's third commercial spaceflight, is planned for September.

Russia hopes to launch its first successful lunar landing mission for nearly 50 years, with a long-delayed takeoff from the far east of the country scheduled for early on Friday morning that the Kremlin aims to tout as a new achievement in space exploration. From a report: The Luna-25 mission will seek to land near the south pole of the moon, collecting geological samples from the area, and sending back data for signs of water or its building blocks, which could raise the possibility of a future human colony on the moon. But the more immediate goal is to prove that Russia still can launch a lunar landing mission after numerous failures in the past, generations of turnover among its scientific experts, delays due to sanctions and now isolation due to its war in Ukraine.

Post-Soviet Russia has launched two failed space landing missions, the Mars-96 in 1996 and Phobos-Grunt in 2011, both of which crash-landed into the Pacific Ocean. "The Russian Federation hasn't had much luck with launching unmanned interplanetary probes," said Vitaly Egorov, a blogger who writes extensively on space exploration. "Now 12 years later they're launching Luna-25 and the main intrigue is whether or not it will succeed in reaching [the moon] or not, and if it does, can it actually land there? "One of the main goals is to let modern specialists put down space probes softly on celestial objects. They haven't had that experience in 47 years. That knowledge needs to be restored for new specialists on a new technological level."

A scientist has observed a "gravitational anomaly" in certain star systems that could potentially upend a fundamental assumption about the universe, according to a new study. Motherboard reports: Kyu-Hyun Chae, an astronomer at Sejong University, has now put these models to the test by analyzing the accelerations of stars in 26,500 wide binaries located within about 650 light years of Earth using imagery captured by the European Space Agency's Gaia observatory. Scientists have previously searched for signs of modified gravity in these systems, but Chae took the next step by developing a new code that could account for special details, like the occurrence rate of so-called "nested" binaries in which the loosely orbiting stars also have close stellar companions. The new data suggests that when the gravitational accelerations of these stars slip below one nanometer per second squared, they begin to move in ways that are more aligned with MOND models than by the standard model. Chae said the findings offer "direct evidence for the breakdown of standard gravity at weak acceleration" and reveal "an immovable anomaly of gravity in favor of MOND-based modified gravity," according to a recent study published in The Astrophysical Journal.

In the new study, Chae reports what he calls "clear evidence" that the movements of binaries at points of weak acceleration seem to sync up with a particular MOND prediction known as AQUAL, according to the study. This discovery suggests that the standard view of gravity cannot account for these motions at low accelerations, which may inspire scientists to rethink aspects of Newton's inverse square law of gravity and Einstein's general relativity, as well as the necessity of dark matter. "Because a large amount of dark matter -- six times the baryonic or ordinary matter based on the standard model -- was required by assuming that general relativity was valid in the low acceleration limit, such a need for a large amount of dark matter is no longer valid," Chae explained. "This does not necessarily preclude the possibility that new particles, such as sterile neutrinos, could not be found. But, it is clear that there is no need for as much dark matter as required by general relativity." "When the results started to show up from my new and more reliable code, my initial reaction was that it was unbelievable," Chae said in an email to Motherboard. "I was feeling like I was dreaming. It seemed so unreal. This is because my results did not match any previous results."

"Several previous results even claimed that the standard gravity was preferred by wide binaries data including Gaia DR3. One group has been claiming an anomaly for some time, but the anomaly seemed not to match well the predictions of existing modified gravity theories. However, those previous studies did not self-calibrate or fully take into account the amount of hidden nested binaries."

sciencehabit shares a report from Science: Whether they're in mortal peril or just suffering from indigestion, infants across the animal kingdom cry out to tell their parents they need help. Unfortunately for them, the parents aren't the only ones attuned to the cries of their vulnerable young. Nile crocodiles are uniquely sensitive to the wails of distressed primate babies, according to a new study -- and the more anxious the cry, the more interested the crocs become. Indeed, according to the research, published today in Proceedings of the Royal Society B: Biological Sciences, the reptiles are even better at identifying the emotional cues hidden in the wails of babies than we are -- perhaps because they've evolved to home in on helpless prey.

To make the gruesome find, Nicolas Grimault, a bioacoustician at the University of Lyon, and colleagues visited a zoo in Agadir, Morocco, that houses more than 300 Nile crocodiles (Crocodylus niloticus) -- a predator particularly well suited to hunting primates and other mammals. The researchers set up loudspeakers alongside four ponds, where, at each, as many as 25 crocodiles sunbathed on red rock ledges. The speakers blared out a series of cries from chimpanzee (Pan troglodytes), bonobo (P. paniscus), and human infants, captured in a variety of situations in order to document a wide range of emotion. The human infants, for example, were recorded both during bath time and vaccination. (You can listen to the sounds yourself in the videos [here].) Many of the crocs, male and female, responded to the cries by seeking out the source of the sound, rapidly approaching the loudspeaker and sometimes even biting it. But their response depended on the characteristics of the cries they heard: Crocs were more likely to respond to recordings with acoustic features known to correlate to highly upset infants such as disharmony, noise bursts, and uneven tones reminiscent of radio static.

The reptiles seemed to be identifying the most distressed prey on the basis of their cries, Grimault says -- a smart strategy for an animal that is a highly opportunistic hunter. "A baby might not scream at the top of its lungs if it's with its mother," Reber adds, "but it might ... if it fell into the water." On average, about one in five crocodiles responded to recordings of human infants experiencing low levels of distress, whereas about one-third responded to the cries of severely distressed human babies. Surprisingly, the crocodiles seemed even better at detecting distress in the cries than humans were. When the researchers asked human volunteers, all of whom had experience with human infants, to listen to the same recorded cries and estimate the level of distress communicated by the sounds, the participants used different features than the crocs did to evaluate the sounds, basing their decisions largely on the pitch of the cries. The researchers note that it's possible some of the crocodiles were acting out of parental concern, rather than blood lust. "Nile crocodile mothers respond to distress calls from their own young, and their attempts to bite the loudspeaker might not be as bad as they look -- mother crocodiles are known to gingerly pick up their own babies in their jaws."

National Geographic: Research does show that heart attacks, also called myocardial infarctions, are on the rise in younger people. Common symptoms include chest pain or discomfort; pain that radiates into the jaw, neck, back or arms; shortness of breath; and feeling weak or faint. A study of more than 2,000 young adults admitted for heart attack between 2000 and 2016 in two U.S. hospitals found that 1 in 5 were 40 years old or younger -- and that the proportion of this group has been increasing by 2 percent each year for the last decade.

The study, published in 2019 in the American Journal of Medicine, also found that people ages 40 or younger who have had a heart attack are just as likely as older adults to die from another heart attack, stroke, or other reason. In fact, increases in heart disease among younger adults in 2020 and 2021 are responsible for more than 4 percent of the most recent declines in life expectancy in the U.S., according to an editorial published in March in JAMA Network. The problem isn't uniquely American. Research shows that adults in Pakistan and India, for example, are also experiencing heart attacks at younger ages.

Researchers are now waking up to another factor why so many places on earth are getting warmer, one that could be filed under the category of unintended consequences: disappearing clouds known as ship tracks. From a report: Regulations imposed in 2020 by the United Nations's International Maritime Organization (IMO) have cut ships' sulfur pollution by more than 80% and improved air quality worldwide. The reduction has also lessened the effect of sulfate particles in seeding and brightening the distinctive low-lying, reflective clouds that follow in the wake of ships and help cool the planet. The 2020 IMO rule "is a big natural experiment," says Duncan Watson-Parris, an atmospheric physicist at the Scripps Institution of Oceanography. "We're changing the clouds."

By dramatically reducing the number of ship tracks, the planet has warmed up faster, several new studies have found. That trend is magnified in the Atlantic, where maritime traffic is particularly dense. In the shipping corridors, the increased light represents a 50% boost to the warming effect of human carbon emissions. It's as if the world suddenly lost the cooling effect from a fairly large volcanic eruption each year, says Michael Diamond, an atmospheric scientist at Florida State University. The natural experiment created by the IMO rules is providing a rare opportunity for climate scientists to study a geoengineering scheme in action -- although it is one that is working in the wrong direction. Indeed, one such strategy to slow global warming, called marine cloud brightening, would see ships inject salt particles back into the air, to make clouds more reflective. In Diamond's view, the dramatic decline in ship tracks is clear evidence that humanity could cool off the planet significantly by brightening the clouds. "It suggests pretty strongly that if you wanted to do it on purpose, you could," he says.

A recently released research reveals a fundamental challenge of developing artificial intelligence: ChatGPT has become worse at performing certain basic math operations. From a report: The researchers at Stanford University and the University of California, Berkeley said the deterioration is an example of a phenomenon known to AI developers as drift, where attempts to improve one part of the enormously complex AI models make other parts of the models perform worse.

[...] Thus far, they have tested two versions of ChatGPT: version 3.5, available free online to anyone, and version 4.0, available via a premium subscription. The results aren't entirely promising. They gave the chatbot a basic task: identify whether a particular number is a prime number. This is the sort of math problem that is complicated for people but simple for computers.

Is 17,077 prime? Is 17,947 prime? Unless you are a savant you can't work this out in your head, but it is easy for computers to evaluate. A computer can just brute force the problem -- try dividing by two, three, five, etc., and see if anything works. To track performance, the researchers fed ChatGPT 1,000 different numbers. In March, the premium GPT-4, correctly identified whether 84% of the numbers were prime or not. (Pretty mediocre performance for a computer, frankly.) By June its success rate had dropped to 51%. Across eight different tasks, GPT-4 became worse at six of them. GPT-3.5 improved on six measures, but remained worse than its advanced sibling at most of the tasks.

During its 54th flight on Mars, NASA's helicopter Ingenuity captured an image of the space agency's Perseverance rover. Space.com reports: Perseverance is nearly out of frame at the top of the photo, which Ingenuity took when it was about 16 feet (5 meters) above the red dirt. Unlike previous sorties, the Aug. 3 flight wasn't a scouting run to aid Perseverance's science activities. It lasted just 24 seconds, reached a maximum altitude of 16 feet and covered no ground laterally, according to Ingenuity's flight log. The mission team designed this short and simple hop in an attempt to help understand what happened during Ingenuity's previous flight, which was cut short unexpectedly.

The mission team designed this short and simple hop in an attempt to help understand what happened during Ingenuity's previous flight, which was cut short unexpectedly. That July 22 sortie was supposed to last 136 seconds and feature several complicated maneuvers. However, Ingenuity stayed aloft for just 74 seconds, touching down after something triggered its "flight-contingency program." [...] Imagery from Ingenuity's navigation camera likely got out of sync with its inertial measurement unit, which helps the little chopper determine its position, speed and orientation. This also happened near the end of Ingenuity's sixth flight, back in May 2021. The mission team soon uploaded a software patch to deal with the issue, but that patch apparently couldn't handle what happened on Flight 53, NASA officials said in the statement. "Since the very first flight, we have included a program called 'LAND_NOW' that was designed to put the helicopter on the surface as soon as possible if any one of a few dozen off-nominal scenarios was encountered," Teddy Tzanetos, Ingenuity team lead emeritus at NASA's Jet Propulsion Laboratory in Southern California, said in a statement.

"During Flight 53, we encountered one of these, and the helicopter worked as planned and executed an immediate landing," Tzanetos added.

Air pollution is helping to drive a rise in antibiotic resistance that poses a significant threat to human health worldwide, a global study suggests. From a report: The analysis, using data from more than 100 countries spanning nearly two decades, indicates that increased air pollution is linked with rising antibiotic resistance across every country and continent. It also suggests the link between the two has strengthened over time, with increases in air pollution levels coinciding with larger rises in antibiotic resistance.

"Our analysis presents strong evidence that increasing levels of air pollution are associated with increased risk of antibiotic resistance," researchers from China and the UK wrote. "This analysis is the first to show how air pollution affects antibiotic resistance globally." Their findings are published in the Lancet Planetary Health journal. Antibiotic resistance is one of the fastest-growing threats to global health. It can affect people of any age in any country and is already killing 1.3 million people a year, according to estimates. The main drivers are still the misuse and overuse of antibiotics, which are used to treat infections. But the study suggests the problem is being worsened by rising levels of air pollution.

The study did not look at the science of why the two might be linked. Evidence suggests that particulate matter PM2.5 can contain antibiotic-resistant bacteria and resistance genes, which may be transferred between environments and inhaled directly by humans, the authors said. Air pollution is already the single largest environmental risk to public health. Long-term exposure to air pollution is associated with chronic conditions such as heart disease, asthma and lung cancer, reducing life expectancy. Short-term exposure to high pollution levels can cause coughing, wheezing and asthma attacks, and is leading to increased hospital and GP attendances worldwide.

Long-time Slashdot reader William Robinson shares a report from the BBC: India's space agency has released the first images of the Moon taken by the Chandrayaan-3 spacecraft, which entered lunar orbit on Saturday. The images show craters on lunar surface getting larger and larger as the spacecraft draws closer. Chandrayaan-3's lander and rover are due to reach the surface on August 23. If successful, India will be the first country to perform a controlled "soft landing" near the south pole. It will also become only the fourth to achieve a soft landing on the Moon after the US, the former Soviet Union and China.

After the spacecraft orbited the Earth for about 10 days, it was sent into the translunar orbit last Tuesday and successfully injected into the lunar orbit on Saturday. Indian Space Research Agency (Isro) said that all checks showed that Chandrayaan-3 was in good "health." It has also pointed out that "this is the third time in succession that Isro has successfully injected a spacecraft into the lunar orbit." Scientists say Chandrayaan-3, the third in India's program of lunar exploration, is expected to build on the success of its earlier Moon missions.

An anonymous reader quotes a report from New Atlas: Scientists have discovered that the Sun produces higher energy light than was thought possible. An unusual type of telescope detected gamma rays with energies of over 1 tera electron volt (TeV), at least five times more energetic than previously known. The Sun emits light spanning a wide range of energies, from infrared through visible light and up to ultraviolet. It was previously predicted that the Sun could produce gamma rays -- electromagnetic radiation with the highest energy -- through interactions with cosmic rays from distant sources, but these would rarely reach Earth to be detectable. A few decades later, these gamma rays were eventually detected by NASA's Fermi Gamma-ray Space Telescope in 2011. With more and more observations over the years since, Fermi found that the Sun was producing around seven times more gamma rays than had been predicted. Their energies were detected at up to 200 giga electron volts (GeV), which is the upper limit that Fermi can pick up.

So for the new study, scientists used a different instrument that's sensitive beyond that limit. The instrument in question is called the High-Altitude Water Cherenkov Observatory (HAWC), and it works in a way unlike your everyday telescope. It's made up of a series of 300 big tanks filled with 200 tons of water each. When gamma rays hit molecules in the Earth's atmosphere, they create a cascade of lower energy particles, and these can interact with the water molecules in those big tanks. Sensitive instruments keep watch for these interactions, and scientists can work backwards to calculate the energy of the original gamma ray. Using HAWC data gathered between 2015 and 2021, the researchers discovered that the Sun was producing gamma rays with energies well beyond that which Fermi detected. They were reaching energies on the scale of TeV, with some spiking to almost 10 TeV. Exactly how the Sun produces them remains a mystery, the team says, but further research will investigate how their energy gets so high and what role the Sun's magnetic field might play. The research was published in the journal Physical Review Letters.

In a neighborhood in Seoul there's an ordinary red-brick, four-story building, reports Bloomberg — but there's something unique about the building's basement office. It's somehow the registered address of the Centre "whose extraordinary claims about a breakthrough in superconductor technology have shocked the scientific community and captivated the world."

Bloomberg also reports that:

- "No one responded when a Bloomberg News reporter knocked on the center's locked doors or reached out via LinkedIn."

- "Goods including bottles of sparkling water delivered to the center's address have been left untouched outside the office's entrance."

- "Multiple attempts to reach the scientists at the Quantum Energy Research Centre were not answered."

- "The center's website has also been closed and says it is 'under construction.'"

However, Kim Hyun Tak, one of the authors of the papers who is a research professor of physics at the College of William & Mary in Virginia, said the skeptical reaction is expected. "It's common practice when a new crucial discovery or invention is made public that there are more people who say that it's not credible," Kim said in a Zoom interview. "It's a natural thing for some people to laugh at it because it's the first time, and they don't even know what it is, but as time passes, they start to believe it...."

In response to questions about why the Quantum Energy Research Centre hasn't provided the materials to other scientists, Kim said that it doesn't have enough inventory of the LK-99 compound nor time to recreate it, and that the researchers have been distracted by the number of journalists trying to contact them. "You know that the office is extremely small and in a poor state." he said. "It's so small, and you need the money to make the compounds. That's why they cannot mass-produce it."

Despite the questions, he remained defiant that the research was sound. "The experimental data speaks for itself," Kim said. "We know it because we're the ones who synthesized it and conducted the studies."
"The claim has been met with widespread excitement globally," adds Bloomberg, "sending related stocks soaring in South Korea and China, but also skepticism as past claims had been later proven wrong."