Tabla de contenidos para December 2025 en BBC Science Focus Magazine

The ring you see glowing eerily here could be the next big step in women’s health. It’s a device for delivering ‘good’ bacteria directly to the vaginal microbiome. The 3D-printed ring is being developed by researchers at the Massachusetts Institute of Technology (MIT). It’s based on existing vaginal ring technology, but instead of releasing hormones to act as a contraceptive, this ring will release Lactobacillus as a preventative therapy. Lactobacillus is a building block in around 70 per cent of the microorganisms in the vaginal microbiome and produces lactic acid, which stops infections like the human papillomavirus (HPV) from being able to grow. HPV causes an estimated 600,000 cases of cervical cancer each year. Clinical studies have shown that the daily application of Lactobacillus is effective at reducing vaginal infections,…

Astronomers have discovered a peculiar ‘moon’ shadowing Earth. Known as a quasimoon, it doesn’t orbit Earth directly, but follows a similar trajectory around the Sun. According to a study published in Research Notes of the American Astronomical Society, the space rock, known as 2025 PN7, may have evaded previous observations because it’s so small. While its exact size isn’t yet known, researchers think it’s approximately 30m (98ft) across. That’s roughly the same as the wingspan of a typical short-haul passenger plane – making it the smallest known quasimoon near Earth. “We’re discovering near-Earth objects faster than ever before, thanks to rapid advancements in technology,” Dr Darren Baskill, astronomy lecturer at the University of Sussex, told BBC Science Focus. “Digital cameras are more sensitive than ever, allowing us to see such…

Scientists have uncovered new DNA evidence that challenges long-held assumptions about Napoleon’s disastrous 1812 invasion of Russia. As his Grande Armée – nearly half a million strong – advanced towards Moscow, it faced fierce resistance, dwindling supplies and the onset of a brutal winter. By the time the troops began their retreat, starvation and disease had taken hold. Now, analysis of soldiers’ remains suggests that, rather than typhus being the main cause of the army’s demise, a mix of infectious diseases may have decimated the French Emperor’s troops. In a new study led by Dr Nicolás Rascovan at the Institut Pasteur in Paris, researchers extracted genetic material from the teeth of 13 soldiers found buried in a mass grave in Vilnius, the capital of Lithuania. Using DNA sequencing on the…

For once, the city council meeting in Portland, Oregon, was full. So full that people had spilled out into an overf low room, where they were watching the meeting play out on a TV. “This is great,” thought Chris Goldfinger, when he arrived. “The community is really engaged.” It was 2018 and Goldfinger, a renowned earthquake expert and emeritus professor at Oregon State University, had come to give the locals the lowdown on the danger they were facing. The danger, which they continue to face today, is an earthquake the likes of which Portland has never seen. An earthquake that’s brewing 200km (almost 125 miles) away, off the Pacific Northwest coast of America, and could bring with it a devastating tsunami. Experts suggest that when this earthquake hits, it’ll bring…

The last words Steve Jobs, the legendary Apple founder, spoke were simple: “Oh wow, oh wow, oh wow.” Their mystery is enticing – what did Jobs, the digital prophet who brought us the smartphone, see as he neared death? We’ll never know. But stories of near-death experiences (NDEs) tantalise the living, and something unique seems to be happening inside our brains as we sense death approaching. Despite NDE testimonies, the moments surrounding death largely remain a mystery to us, especially when it comes to the actual experience of dying. But scientists have recently begun to explore what happens in the final moment of life by gathering data on brain activity from patients who are dying. Using electroencephalogram (EEG) recordings, researchers are able to watch how patterns of brain activity change…

Several years ago, scuba divers were exploring coral reefs around Kumejima Island in Japan’s Ryukyu archipelago when they saw what looked like a graveyard of tiny panda skeletons. Well, not exactly skeletons – more like skeletons with the living heads of pandas still attached. These things are, at most, around 2cm (3/4in) long – about the length of a fingernail. At one end, there’s a white ‘head’ with a black nose spot and two black panda-like eye patches. Visible through the transparent body is a stack of white horizontal lines, which look like bony ribs. There’s even a black spot lower down that could be a tail. All very strange. “THE PANDA SKELETONS ARE UNUSUAL ENOUGH TO BE ASSIGNED THEIR OWN SPECIES” The divers recognised these skeleton creatures were a…

Tuberculosis (TB) is an airborne infection that many people think of as a disease of the past. But after decades of steady decline in high-income countries such as the UK and the US, the number of people diagnosed with TB is climbing. In England, the UK Health Security Agency reported that TB diagnoses increased by 13 per cent in 2024 compared with the previous year, to 5,480 people. This number is still small relative to other high-burden countries, and England remains, just, under the World Health Organization (WHO) threshold for ‘low incidence’ status – 10 cases per every 100,000 population. But these figures, and similar trends in the US, are a clear sign that previous progress has stalled and we’re no longer on the right trajectory for ending TB. WAKE-UP…

The very first impression of what you might be like as a person comes from your name. Or more precisely, the sounds your name makes. Canadian psychologists have found that if you’re a Katie or a Jack, for example, you’ll be expected to be bubbly and outgoing, the life and soul of every party. If you’re an Owen or a Lauren, however, you’ll be perceived as one of life’s natural peacemakers. Why? Because the human mind automatically associates the short, abrupt sounds in ‘Katie’ or ‘Jack’ with the quick, bouncy energy of an extrovert, while we naturally link names containing softer sounds with agreeableness. Of course, in reality, Jacks are no more likely to be extroverted than Owens, but research has repeatedly found that our initial perceptions of a person…

HOW TO SEE THE GEMINID METEOR SHOWER WHEN: DECEMBER Meteor showers occur annually when Earth passes through the orbital detritus of comets. This sounds more dramatic than it is, as the material encountered is sparse and typically the size of sand grains. But larger particles do exist and these are the ones that produce bright, often spectacular, trails. Meteors can be seen at any time, but seeing them requires luck. Meteor showers are different because we know the material is there and we know how much of the debris we’re likely to encounter. Shower activity typically spans many days, rising from barely anything to a marked peak, before subsiding back to barely anything again. This will be the case with this year’s Geminid meteor shower, which is active between 4–17…

PENCILS AT THE READY! ACROSS 1 Bears used as a weapon (5) 4 Informed about liberal jargon (5) 8 Clamber about branch (5) 9 Capitol wandered out of vision (7) 10 I'm a moving target (3) 11 Equestrian clause (5) 12 Unassuming fashion on the way (6) 14 Nocturnal bear somehow keeping emissions balanced (6,7) 17 Beat on album captured without a key (6) 19 Leave initial direction to a minimum (5) 22 Mimic primate (3) 23 A man catches former pupil using oxygen (7) 24 Block Ivan swimming length (5) 25 Duck, awfully odd, say, returning (5) 26 When nature contains a way of changing colour (5) DOWN 1 Dismiss people, in the event (4,4) 2 Unable to see tie left inside (5) 3 Stop me returning to pub and leave (7) 4 Seen, heard, and located (5) 5 A Catholic curse about the plaintiff(7) 6 Key university…

The green flash slicing through the skies in this shot is a fireball. It’s a meteor, in other words, but an exceptionally bright one. Meteors are fragments that break off comets, in this case, the Swift-Tuttle comet (the source of the annual Perseid meteor shower). As Earth crosses the orbital path of a comet, it passes through the trail of debris the comet leaves behind. Some of the fragments enter our atmosphere and burn up from friction as they tear through the air. The bigger or faster the meteor, the brighter it glows. And depending on the meteor’s chemical composition and how it reacts with the oxygen in Earth’s atmosphere, it could burn blue, yellow, white, red or, as seen here, green. Fireballs are a rare sight – the American…

Few websites are as well-known as Wikipedia. The online encyclopedia was founded in 2001 by American tech entrepreneur Jimmy Wales, who, at the time, was working on a similar, expert-led project called Nupedia. Nupedia didn’t work out, but its successor, Wikipedia, has become one of the most influential sites on the internet. Today, its English-language edition alone hosts more than seven million articles. Much has changed in the 25 years since its launch, however, both online and in the real world. Facts seemingly carry less weight when they can be easily written off as fake news, and artificial intelligence is raising questions about where information comes from and how we use it. Wales’s new book The Seven Rules of Trust, addresses some of these concerns. BBC Science Focus sat down…

THERE'S A CATERPILLAR THAT WEARS THE BONES OF ITS PREY A newly discovered species of caterpillar was seen wearing the leftover body parts of the prey it had devoured as camouflage. Dubbed the ‘Bone Collector’, this bizarre caterpillar is a rare exception in the insect world: just 0.1 per cent of moth and butterfly species are carnivorous. EXTINCTION ISN'T FOREVER It began in January with news of the development of an artificial womb to implant in a marsupial as a means to bring back Australia’s extinct thylacine. In March, Colossal Biosciences, the company behind this move, genetically engineered mice to resemble woolly mammoths. Then, in April, Colossal successfully brought back the American dire wolf, which had been extinct for over 10,000 years. ORCAS GOT EVEN ODDER As well as devouring…

It’s no secret that protein is big business right now. Browse the shelves of your local supermarket and you’ll see just how many products tout their protein content – whether it’s in natural sources, such as meat and milk, or in more processed items, like breakfast cereals and pasta. And for anyone looking to supplement their protein intake or get it from non-animal sources – gym users or vegans, for example – there are protein powders. But a worrying new report has identified another substance, besides protein, hiding in some of these powders: lead. Given this news, how is this substance getting into these supplements and what’s it doing to you if you’re using them? LEAD LEVELS Consumer Reports (CR), an independent non-profit organisation based in the US that assesses…

My first signs of social anxiety emerged when I was around six years old. I’d been invited, at the last minute, to the birthday party of a boy in my class. When I arrived, his older brother noticed that I was shaking. He asked if I was shy. “I’m just cold,” I told him, even though it was the middle of spring. He looked doubtful as he took my arm and led me into their living room. My parents hoped that those fears would leave me as I grew up, but they continued well into adulthood. The shaking may have stopped, but my mouth would go dry and I’d blush heavily whenever I had to speak in a team meeting. Such experiences are surprisingly common. The UK’s National Institute for…

As an astronomer, I collect stars. There are several hundred billion of them in our Galaxy, the Milky Way, so it’s important to find a way to categorise them. While others might rank their stars by colour or size, I prefer to order them chronologically. That way, we can simply look through them to read the history of the Universe. There is, however, a glaring gap in my collection: the very first generation of stars are missing. And I’m not the only one to have encountered this problem. All the world’s astronomers – despite the multitude of telescopes at our disposal and centuries of diligent observation – have failed to find a single one. If we’re trying to read through the history of the Universe, then our library is missing…

JEANNIE HOLMES, VIA EMAIL DO ANY ANIMALS USE OTHER ANIMALS FOR SPORT? Dolphins have been observed, on various occasions, holding pufferfish in their mouths. The terrified fish soon inflate with seawater until they look like a spiky tennis ball, which the dolphins then pass around and toss into the air. This could be a game – part of the dolphins’ repertoire of naturally playful behaviours – but marine mammal experts aren’t sure what’s going on. Maybe younger dolphins are practising their echolocation skills, finding pufferfish hiding on the seabed and then playing with them like a cat taunts a mouse. However, it’s clear the dolphins know not to eat the pufferfish, which are full of a deadly chemical called tetrodotoxin. If the marine mammals were planning to eat them, they…