2026-09-12の世界

Have scientists found a strange twin for one of Saturn's most famous features? For more than 40 years, astronomers have watched a giant six-sided cloud pattern, called a hexagon, spin around Saturn's north pole. Now, a new study published on September 2, 2026, in the journal Science Advances reveals a surprising counterpart: a ten-sided pattern, or decagon, circling the planet's south pole. The discovery was led by Agustín Sánchez-Lavega of the University of the Basque Country in Spain, working with NASA's Hubble Space Telescope and ground-based images taken by amateur astronomers Trevor Barry and Jean-Paul Oger. The team first noticed hints of the shape in ground-based pictures from 2024, and Hubble data later confirmed it had already existed in 2023. Unlike the steady northern hexagon, which NASA's Cassini spacecraft studied for 13 years without spotting anything similar in the south, this new decagon seems to be changing. NASA scientist Amy Simon said the feature is different from the hexagon and appears to be strengthening. Researchers still do not fully understand why this ten-sided shape formed. They plan to keep watching Saturn with Hubble and the James Webb Space Telescope to learn whether the decagon will last.

Who were the mysterious Denisovans, and how did they live? Scientists in China have just found new clues. A research team led by Professor Fu Qiaomei at the Institute of Vertebrate Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences, has identified rare Denisovan fossils inside Bianfu Cave in Yunnan province, southwest China. The team studied more than 60,000 bone fragments recovered from the cave. Instead of testing every single piece, which would be extremely costly, researchers first sorted fragments by shape and then used protein-analysis techniques to identify which ones came from humans. This method revealed three Denisovan specimens, including the first-ever Denisovan forearm bone, called a radius, along with two skull fragments. The fossils are between 134,000 and 167,000 years old. The forearm bone has a large upper joint similar to a Neanderthal's, but its overall shape looks more like that of a modern human, suggesting Denisovans moved and behaved in their own unique way. The findings, published on September 10, 2026, by China's Xinhua news agency, based on a study in the journal Nature, fill an important geographic gap, showing that Denisovans once lived far south of Siberia, on the warm Yunnan-Guizhou Plateau.

Did you know that most insects on Earth live in places scientists know the least about? A new international study, published on September 7, 2026, in the journal BioScience, warns that tropical regions, home to more than 80 percent of the world's insect species, have some of the biggest gaps in scientific knowledge. The research was led by Shawan Chowdhury, head of the Global Change Ecology Lab at Monash University in Australia, together with scientists from countries including Bangladesh, Uganda, Brazil, and India. The team found that nearly 26 percent of global insect records in one major database come from the United Kingdom alone, even though the UK holds only a tiny fraction of the world's insect species. In a case study from Bangladesh, researchers identified 111 butterfly studies, but only 34 had appeared in international journals, and just three focused on conservation. Meanwhile, ordinary people had already posted photos of 167 of the country's 169 threatened butterfly species on Facebook. The scientists argue that conservation should stop relying only on outside experts, calling this pattern 'parachute science.' Instead, they recommend training local scientists, using citizen photos, and connecting research directly to real conservation decisions.

Why do baby snakes almost always curl in the same direction before they can even move? A team of scientists led by Tetsuto Miyashita at the Canadian Museum of Nature has finally solved this strange mystery. The researchers examined more than 900 embryos from 39 species of snakes and other limbless reptiles, collecting images from scientific papers and museum collections around the world. Using detailed CT scans, they studied the hidden anatomy inside snake eggs. They discovered that a growing snake embryo's body lengthens much faster than its gut can keep up with. Because the gut cannot stretch fast enough, it acts like a tether, pulling on the lengthening body and forcing it to buckle and twist. Since the yolk always sits on the left side of the embryo, this twisting naturally pushes the body to coil toward the right. Miyashita explained that the body buckles and twists into coiling because the detached gut restrains the lengthening body. Later, as the embryos grow bigger, the yolk shrinks, and their muscles mature enough to move on their own, so some snakes eventually shift into a left-handed coil instead. The study, published on August 31, 2026, in the journal Current Biology, began as a remote research project during the COVID-19 lockdown.