Sommaire pour June 2025 de BBC Science Focus Magazine

Mars once had vast oceans on its surface. Then its magnetic field weakened, its atmosphere thinned, and its water vanished. But the numbers don't add up. For the Red Planet to have transformed from a watery world into the red dust bowl we know today, all that water had to end up somewhere. So, where did it go? A new study published in the National Science Review may finally have an answer, as a research team from China, Australia and Italy have identified a vast reservoir of water that may lie deep beneath the planet's surface. What's more, unlike possible icy reservoirs found on other parts of Mars, this water is thought to still be in its liquid form, making it one of the best bets yet that extraterrestrial life…

1. Triceratops Weighing up to eight tonnes and stretching nearly 9m (30ft) long, Triceratops was the largest of the horned dinosaurs. With 1m (3ft)-long brow horns and a vast frill, it likely evolved alongside T. rex in an evolutionary arms race between prey and predator. 2. Spinosaurus Larger than T. rex, Spinosaurus was a predator like no other and built for life in the water. With a 2m (6.6ft) sail on its back, a powerful paddle-like tail and webbed feet, it was perfectly adapted to swim and hunt in the rivers and swamps of ancient Morocco. 3. Gastonia Gastonia is one of the spikiest dinosaurs ever discovered – an armoured member of the herbivorous ankylosaur family covered in defensive spikes. Unlike most of its kind, it was social: fossils of…

What a time to be a dog. Right now, it's estimated that owners spend around £2,000 (about $2,600) a year to take care of our favourite four-legged friends (sorry, cats), with that figure including up to £600 (almost $800) on grooming and £300 (nearly $400) on treats. But modern pooches aren't only pampered – they're enjoying longer, healthier lives than ever. One study of dogs in Japan found that their lifespans have increased by over 50 per cent since the 1980s. That figure could rise further. A wave of cutting-edge canine science is sweeping the globe, with everything from the Dog Aging Project's 50,000-pet study, to biotech firms racing to develop anti-ageing drugs for dogs. It all means we could be less than a decade away from cracking the code…

Somehow, we've seriously underestimated confidence. While most of us likely want more of it (only 16 per cent of us describe ourselves as ‘very confident’, according to a YouGov survey), many of us don't realise just how profoundly a bit more self-belief could change our lives. Far from being just a trait that's useful for delivering TED talks or impressing at dinner parties, confidence has long been known to be a powerful predictor of life outcomes. Truly confident people tend to be healthier, happier and more resilient. They perform better in school, report greater job satisfaction and career success, build stronger relationships and are often more effective team players. On the flip side, low confidence goes beyond occasional moments of selfdoubt. It's associated with the fear of judgment, poorer mental…

If you've ever read anything about cosmology, you'll have come across an astonishing statistic: all the matter around us, everything we see and touch, every star and gas cloud and planet, makes up just five per cent of the energy in the Universe. Of everything else, around 25 per cent is made up of dark matter, and the rest – a baffling 70 per cent of everything that exists – is dark energy. Cosmologists say this must be the case because of the way the Universe is expanding. But it isn't just that the Universe is expanding; it's that the expansion is accelerating, and something must be driving that. We call that unknown force dark energy. But there's a niche area of cosmology research that disputes this explanation. It argues…

Far from the shore, out in the vast expanses of the open seas lives a group of unusual animals, collectively known as ‘neuston’. Their home is the giant, two-dimensional skin of the sea, which forms a link between the atmosphere and the ocean. Within this family, one of the most curious creatures is a type of sea slug, or nudibranch, more commonly known as blue dragons, sea swallows or blue glaucus, thanks to their scientific name Glaucus atlanticus. Blue dragons spend their lives hanging down from the surface, buoyed by a bubble of air that they swallow. To keep hidden from predators, they use a two-sided biological trick known as countershading. Hanging upside-down, the underside of their body is vivid blue, blending into the ocean below and hiding from winged…

PENCILS AT THE READY! ACROSS 1 Leave head of divinity to taper off(6) 4 Behold copper getting married to doctor (5) 8 Played game, wearing large sparkle (5) 9 A French dream about not carrying weapons (7) 10 Wonderful police officer, in short (5) 12 Sword for trim girl (7) 13 Meet corgi, terribly nasty, yet average (9,4) 15 Exaggerate concerning part of the play (7) 17 Fool gets by in canyon (5) 19 Team about to go in, multiplied by itself (7) 20 Thanks for every slender candle (5) 22 Groups of the French set off(5) 23 Connection to a game (6) DOWN 1 Remove oxygen, say, for painter (5) 2 Hippies eating food (3) 3 Contrition concerning dots and dashes (7) 4 Plate, unusually, is sprung (5) 5 Composed car melody in a friendly way (9) 6 President's event (7) 7 Beauty making Cupid hurtle about…

Curious Cases Prof Hannah Fry and Dara Ó Briain ask scientists an age-old summertime question: Why do some people get bitten by mosquitoes more than others? Listen now on BBC Sounds TechXplore – Japan: From North to South Tech reporter Paul Carter (above) travels to Japan's biggest innovation hubs to discover how technology is protecting the island nation's finite resources. Watch now on BBC iPlayer BBC Inside Science: The mysteries of the ocean floor New research claims that just 0.001 per cent of the world's deep seafloor has been seen by humans. Drs Katy Croff Bell (above) and Anna Gebruk discuss how we might see more. Listen now on BBC Sounds…

LONDON, UK What, at first glance, appears to be a field of blue daisies is actually the protective lining of the human colon. When a sample is stained and viewed under a microscope, colonic crypts – deep pockets in the tissue lining – appear as these ‘flowers’. Each ‘flower’ contains specialised cells that produce a protective layer of mucus, which both prevents rogue organisms from harming the colon and helps it absorb nutrients. This sample was taken from a patient with Hirschsprung's disease, a rare bowel condition where children are born with some of the nerve cells missing in their large intestine. This breaks the protective mucus barrier, leaving the colon vulnerable to tissue damage and inflammation. The picture won this year's National Institute for Health and Care Research Great…

“What's considered ‘enough’ sleep in one country might feel like too much or not enough in another” It doesn't matter whether you get eight hours of sleep or six and a half – as long as that's normal for where you live. At least, that's according to a new study by researchers at the University of Victoria and the University of British Columbia, in Canada. The paper argues that cultural norms shape your sleep needs, so recommendations should be tailored to each country rather than following a universal eight-hour rule. “Sleep is shaped by more than just biology – it's influenced by culture, work schedules, climate, light exposure, social norms and other factors,” lead author Dr Christine Ou, an assistant professor at Victoria's School of Nursing, told BBC Science Focus.…

An enormous cloud of hydrogen gas – one of the largest single structures ever observed in the sky – has been discovered surprisingly close to Earth. Named Eos after the Greek goddess of the dawn, the cloud was detected because of its faint far-ultraviolet light, which is naturally emitted by hydrogen molecules. Known as molecular clouds, these enormous structures of gas and dust are the cradles where new stars are born. “This is the first-ever molecular cloud discovered by looking for far-ultraviolet emission of molecular hydrogen directly,” said Prof Blakesley Burkhart, author of the study published in Nature Astronomy. “The data showed glowing hydrogen molecules detected via fluorescence in the far ultraviolet. This cloud is literally glowing in the dark.” Located just 300 light years from Earth on the edge…

If you've spent even a brief amount of time interacting with an artificial intelligence (AI) chatbot, you'll likely appreciate the technology's potential for acting as a personal therapist. If I'm ever feeling down or worried, I turn to Claude, a model from Anthropic, the AI safety and research company. It's a great listener and isn't judgmental. What's more, at least on the surface, Claude's advice usually seems measured and draws on genuine psychological principles. More people are turning to AI for this kind of relationship. Beyond the general-purpose AI models, such as ChatGPT and Grok, there's an increasing number of AI bots designed specifically for therapy, including Woebot (founded by psychologist Dr Alison Darcy) and Therabot (developed by researchers at Dartmouth University in the US). None of them yet have…

Ask most people if they'd buy a secondhand electric car and they'll walk the other way. Others will roll their eyes and say they wouldn't want to take the risk. But a few will say they already have… and it's the best thing they've ever done. I'm one of them. 15 years of daily electric vehicle (EV) driving, owning seven different electric models and covering 170,000 battery-only miles gives me a clear perspective. And in all that time and all those miles, nothing has gone wrong. I got my first and, so far, only EV repair bill the other day. It was for £375 for front control arm bushes on the Tesla Model 3 that I've owned for five years and have driven for 50,000 miles. MOTORING MADE SIMPLE Buying…

The classic rule for converting human years to dog years is to multiply by seven, so a three-yearold pooch would be 21 dog years old. But we now know that this is an oversimplification. Researchers at the University of California San Diego measured the biological age of 100 labrador retrievers using an ‘epigenetic age’ DNA test, and compared results of similar tests in humans. Their results hinted that labradors grow up faster than the seven-year rule would suggest, reaching the equivalent of 31 human years in their first 12 months. Thereafter, things slow down, with a 12-year-old lab being equivalent to a 71-year-old person. That's 13 years less than 12 × 7 = 84. To calculate your dog's epigenetic age (this will be most accurate if your dog is a…

1. ACT THE PART It's the kind of advice you've likely heard from an Instagram ‘charisma coach’, but surprisingly, there's real science behind the ‘fake it ‘til you make it’ mantra. “Faking it is absolutely central to confidence,” says clinical psychologist Prof Ian Robertson. “Taking action in spite of feeling anxious can activate the ‘success mechanisms’ in your brain.” Robertson suggests thinking of yourself as an actor in a play, with your character being ‘Confident Person’. Speak up in a meeting the way Confident Person would, hold eye contact, take up space. Eventually, your body starts to believe that you are Confident Person and the behaviour comes more naturally. “This feels fake because there's a discordance between your behaviour and what you feel,” Robertson says. “But all confidence feels fake…

High cholesterol is, unfortunately, very common. The British charity Heart UK estimates that nearly half of all adults in England have above-average cholesterol levels, while the US Centers for Disease Control and Prevention estimate that 1 in 10 Americans – that's 34 million people – have cholesterol levels exceeding the high-mark of 240mg/dL (milligrams per decilitre). These people are all at high risk for heart attacks and might not even know it. High cholesterol doesn't come with any obvious symptoms and, unless a person has recently had their blood tested or experienced a medical issue, it's likely that the cholesterol in their blood is a mystery to them. If you're worried about your levels, it's a good idea to have a chat with your doctor. If there's cause for concern,…

Have you ever felt so stressed that you just sort of froze? It's a strange sensation. Your body goes still, you feel kind of numb but, at the same time, your senses are working overtime. You know you have to act soon, but it's as if there's a brake on the system. If you know the feeling, there's a good chance that a moment of great stress triggered it. Psychological freezing is an adaptive defence response to stressful or dangerous situations. Like our fight-or-flight response, it evolved in animals as part of the automatic reaction our nervous system mounts when we experience either real or imagined threats. When we freeze, our heart rate drops, our breathing slows and our blood pressure changes. Our pupils might dilate and our muscles can…

No, this isn't a slice of cosmic bell pepper. It's actually the most detailed image taken to date of NGC 1514, a planetary nebula in the Taurus constellation approximately 1,500 light-years from Earth. Also known as the Crystal Ball Nebula, its two rings – one on top of the other – are formed from the gas and dust ejected by a dying star at the nebula's centre. Invisible to the naked eye, the rings were first revealed in 2010 by NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft. This new image, captured by the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope, provides a much clearer picture of the swirling clumps of material and the holes punched through the central pink region. The jaw-dropping sight has been 4,000 years in…

Archaeologists uncovered the first physical evidence of Roman gladiators fighting lions after bite marks on a skeleton excavated in York, England, were identified as those of a lion. The remains, found alongside 80 other male skeletons at Driffield Terrace – one of the best-preserved gladiator cemeteries in the Roman world – belong to a man who died around 1,800 years ago. In a new analysis of the skeleton, the research team took 3D scans of the tooth marks and compared them to sample bites from a lion at a zoo. It was a match. “This is a hugely exciting find,” said Malin Holst, lecturer in osteoarchaeology at the University of York. “We can now start to build a better image of what these gladiators were like in life, and it…

“Researchers have observed unusual activity, including small earthquakes” A huge ‘zombie’ volcano in Bolivia is showing signs of life, but thankfully scientists say that there's little immediate risk of an eruption. Uturuncu, a towering peak in the Central Andes, last erupted around 250,000 years ago. Yet for decades, researchers have observed unusual activity, including small earthquakes and a distinctive ‘sombrero’ pattern of ground deformation – the centre of the volcano is slowly rising, while the surrounding area sinks. Until now, the cause of this unrest remained unclear. But a new study published in the journal PNAS reveals that heated liquids and gases are still migrating beneath Uturuncu, creating pockets of pressure that deform the surface. The international team of researchers from China, the UK and the US used seismic data…

When you think of dinosaur fossils, you probably picture parched deserts or badlands scorched by the Sun. But one of the world's richest dinosaur graveyards is buried in a less likely setting: a quiet patch of forest in northern Alberta, in Canada. It's called the Pipestone Creek Bonebed and it's home to tens of thousands of bones – all from a single, bizarre-looking species of horned dinosaur called Pachyrhinosaurus. The site, and the mystery of why so many of these animals died at once, is the focus of a new episode of Walking With Dinosaurs – the landmark BBC series returning to screens after more than two decades (see more on p26). We spoke with Prof Emily Bamforth, a palaeontologist and curator at the Philip J Currie Dinosaur Museum in…

Arecent review published in The Lancet Haematology, led by Dr Ashley Benson and Dr Jamie Lo from Oregon Health and Science University has reported that iron deficiency affects up to one in three women, making it the most common nutrient deficiency in the world. Iron plays a vital role in the body. It's essential for making haemoglobin (the protein in red blood cells that carries oxygen from the lungs to the rest of the body). It also supports energy production, brain development and a healthy immune system. Without enough of it, the body struggles to function at its best and in children, iron deficiency can hinder growth and cognitive development. The average adult human body contains just 3–4g (about 0.1oz) of it – a tiny amount that classifies it as…

OUT OF CONTROL Why haven't you gotten a controller for your smartphone yet? Not only is there a growing catalogue of premium games available in app form – from Fortnite to Apex Legends to Resident Evil – but also both Xbox and PlayStation now allow for Remote Play, which means you can get your console games onto your smartphone screen while your other half hogs the TV. There's a ton of options out there, but arguably the controller that sets the standard is now the Backbone Pro, which has added Bluetooth to play nice with pretty much any device you can find in your house. Backbone Pro £169.99, backbone.com …GRILL OF MY DREAMS This isn't new, but I've been thinking about buying one all year, so it's worthy of the…

They knew the weather would be bad. But the three-person film crew, in Antarctica to document emperor penguins for a BBC documentary, decided to press ahead. “We wanted to film in these conditions,” says Stefan Christmann. Footage of the birds in a blizzard would showcase this quintessential aspect of Antarctic life. “The weather was more severe than we'd anticipated, but still manageable,” Christmann says. But as the team journeyed back to base, conditions plummeted. Visibility dropped to about 2–5m (5–16ft). “We couldn't see anything,” Christmann says. “We had to drive our ski-doos just with the GPS.” Until, that is, the battery in Christmann's GPS unit failed. He had to stop to replace it, knowing that stopping meant losing sight of his companions. Then, when he reached for his backpack, the…

IF PRESENT, NOCTILUCENT CLOUDS ARE TYPICALLY SEEN LOW ABOVE THE NORTHWEST HORIZON 90–120 MINUTES AFTER SUNSET, OR A SIMILAR TIME BEFORE SUNRISE, LOW ABOVE THE NORTHEAST HORIZON. THEY OFTEN SHOW FINE MESH-LIKE STRUCTURES OR HERRINGBONE PATTERNS AND HAVE A DISTINCTIVE SILVERY-BLUE COLOUR. A LOW, FLAT HORIZON IN THE VIEWING DIRECTION IS RECOMMENDED. The summer months are difficult times for stargazing. The length of day is at its greatest on 21 June, the summer solstice, when Earth reaches a point in its orbit where its northern pole is the most tilted towards the Sun. In this position, from the northern hemisphere, the Sun climbs to its highest altitude above the southern horizon around the middle of the day, but also only sinks to a minimum altitude below the northern horizon in…