

Science In Action
BBC World Service
The BBC brings you all the week's science news.
Episodes
Mentioned books

Jul 24, 2025 • 30min
Discovering Betelgeuse’s Betelbuddy
Have we found Betelgeuse’s ‘Betelbuddy?’ An astronomical mystery seems to be solved as the long-predicted stellar companion to the bright star Betelgeuse has been detected by a team of researchers led by Steve Howell of the NASA Ames Research Center using the Gemini North telescope in Hawaii. Steve discusses this breakthrough alongside astronomer Andrea Dupree of the Harvard Smithsonian Center for Astrophysics, who has discussed the predictions of this star on previous Science in Action programmes. Malaria is a mosquito-borne disease caused by the parasite plasmodium that kills more than half a million people each year. George Dimopoulos of the Johns Hopkins Malaria Research Institute is using gene editing and gene drive technology to target the parasites as they develop in the guts of mosquito. Can this new method disrupt the malaria parasite life cycle safely and sustainably? Our gut microbiomes are linked to our brains, but how can the bacteria in our colon communicate with our nervous system? M. Maya Kaelberer of the University of Arizona explains this neurobiotic sense, suggesting that the microbes in our large intestine communicate with specialised sensory cells in the gut. These cells send signals up to our brain and regulate our appetite. So, who really decides when you're hungry? Is it you, or is it your microbiome? Presenter: Roland Pease
Producer: Imaan Moin with Alex Mansfield
Production Coordinator: Jana Bennet-Holesworth (Image: Betelgeuse and Its Stellar Companion in Orion. Credit: International Gemini Observatory/NOIRLab/NSF/AURA Image Processing: M. Zamani (NSF NOIRLab))

Jul 17, 2025 • 28min
Biggest black hole merger observed
Two black holes have collided and combined in the largest merger yet observed. Mark Hannam of Cardiff University and member of the study explains how the Interferometer Gravitational Wave Observatories (LIGO) detected this ‘violent’ event through spacetime.
The lifestyle of ancient humans had an impact on their risk for infectious diseases. Astrid Iversen of the University of Oxford explains how the shift away from being hunter-gatherers played a role in the origins of human pathogens. Nitrogen fixation, or the process of organic compounds accessing nitrogen from the atmosphere via microorganisms, plays a key role in climate modelling. But prior estimations have long been missing key data to make accurate analysis. Carla Reis Ely of Oak Ridge Institute for Science and Education shares the updated facts and figures on global nitrogen fixation. How intelligent is artificial intelligence? Can AI start discovering new scientific laws in the year? Keyon Vafa of Harvard University put several AI models to the test to see if they could discover Newton’s law of gravity and understand the world around us.
Presenter: Roland Pease
Producer: Imaan Moin
Production Coordinator: Jana Bennet-Holesworth (Image: Black Hole, digital illustration. Credit: Aaron Horowitz via Getty Images)

Jul 10, 2025 • 34min
Tracking ocean circulation systems
The European Space Agency plans to use satellite gravity data to track weakening ocean circulation systems. Rory Bingham of the University of Bristol explains how these satellites can ‘weigh’ the Earth’s water and might help resolve whether we’re approaching the climate tipping point of a shutdown of ocean circulation in the Atlantic Ocean, something we've been following for a while. Scientists have been able to retrieve ancient proteins from fossilized tooth enamel in the Canadian High Arctic. Ryan Sinclair Paterson from the University of Copenhagen tells us how he can fill in the blanks of the molecular tree of life with these proteins from over 20 million years ago. A few weeks ago, we discussed evidence of an impact of a massive crater in north-western Australia from over 3 billion years ago. However, recent independent evidence from another team of geologists indicate that the size and age of this crater’s impact may not be what some had previously thought. Alec Brenner of Yale University talks us through his analysis of the geologic evidence. Finally, we rediscover a forgotten pioneer of fusion science. Mark Chadwick discusses the research done by then-graduate student Arthur Ruhlig that helped develop the hydrogen bomb and thermonuclear physics. [This audio has been corrected since original broadcast to amend a misattribution in the script. Our apologies.]Presenter: Roland Pease
Producers: Imaan Moin with Alex Mansfield
Production Coordinator: Jana Bennett-Holesworth (Image: Map of North Atlantic Ocean currents, with Gulf Stream and other currents. Credit: PeterHermesFurian Via Getty Images.)

Jul 3, 2025 • 36min
Bird flu surges in Cambodia
There's a surge in cases and deaths from H5N1 bird flu in Cambodia - we hear what's the driver and how concerned we should be. Erik Karlsson, Head of Virology at the Pasteur Institute in Phnom Penh and director of the WHO’s H5 Reference Laboratory has been watching the uptick.An interstellar interloper has been spotted entering our solar system. Most likely a comet, and possibly visible in the sky, it’s just the third such visitor we’ve ever seen. Josep Trigo of Spain’s Institute of Space Sciences (CSIC) and the Catalan Institute for Space Studies is one of many astronomers keeping his eye out.DNA from an ancient Egyptian buried in cave 2,500 BCE, the oldest to date, tell a tale of travelling ancestors, according to research led by Adeline Morez of Liverpool John Moore’s University and published in Nature.Also, Corey Allard of Harvard university has been looking at a particular type of sea slug. Published in the journal Cell, the work has been trying to work out how these slugs effectively nurture and manage stolen chloroplasts – stolen from ingested plant cells - within their own bodies. Artfully, they may use these “Kleptoplasts” to dodge periods of food shortage. Presenter: Roland Pease
Producer: Alex Mansfield
Production Coordinator: Jazz GeorgePhoto Credit: Institut Pasteur du Cambodge

Jun 26, 2025 • 38min
Vera C. Rubin Observatory first images
Tony Tyson, a pioneer in digital astronomy from UC Davis, discusses the unveiling of the first images from the cutting-edge Vera C. Rubin Observatory in Chile. He reflects on its potential to transform our understanding of the universe. Joy Zheng, a social scientist, emphasizes the ethical considerations of the SYN Human Genome Project, which aims to create synthetic human chromosomes. Jason Chin shares insights on the ambitious endeavor to manipulate human DNA, highlighting both the scientific breakthroughs and the responsibility researchers have in addressing public concerns.

Jun 19, 2025 • 42min
Half a universe once lost now found
The universe is thought to consist of 70% Dark Energy, 25% Dark Matter, and just 5% Baryonic matter which is the atoms that make up you and me. At least, that’s what the models suggest. But a well-kept secret between astronomers and cosmologists for all these years has been that they have not actually ever seen almost half of that 5% normal matter because it is thinly dispersed as gas between the galaxies and galactic clusters. This week, two studies have been published putting that right.Satisfactory model-match #1:
Liam Connor of Harvard University with colleagues from Caltech have been using a mysterious phenomenon called Fast Radio Bursts (FBRs) to infer what the intergalactic medium is in between, and how much of it there is. Satisfactory model-match #2:
Konstanios Migkas of Leiden University and colleagues have been looking at the very faint x-ray signal from the intergalactic medium, removing the incidental x-ray sources such as black holes, and have managed to identify some structure - in this case a mind-bendingly huge filament of ionised gas stretching between two galactic superclusters - confirming the state of “Warm Hot Intergalactic Medium” (WHIM) as predicted for much of the universe.Of course, there is not just the cosmological standard model (lambdaCDM) that these satisfy in science today. There is also the remarkably resilient Standard Model of particle physics. A report this week from the US National Academies recommends the US begins building the world’s next particle collider to follow the work of the LHC (and FCC) at Cern. It should, as University of Tennessee at Knoxville’s Tova Holmes tells us, collide not ordinary, stable, easy to manipulate particles like protons and electrons, but muons. Finally, Shana Goffredi of Occidental College in California, has found a VERY odd spider. Diving to depths in the submersible Alvin, they have found that a species of small sea-spiders, Sericosura, actually farm bacteria on their exoskeleton. Why? Because they hang around methane seeps on the ocean floor, where a specialist bacteria can metabolize methane – something the spiders themselves can’t do. Not only do the spiders then graze on the bacteria they carry around, they even pass samples of the bacteria onto their offspring by leaving bacterial lunch-boxes in their egg-sacs.Presenter: Roland Pease
Producer: Alex Mansfield, with Sophie Ormiston
Production co-ordinator: Jasmine Cerys George(Photo Credit: Jack Madden, IllustrisTNG, Ralf Konietzka, Liam Connor/CfA)

Jun 12, 2025 • 35min
The first solar polar pictures
ESA’s Solar Orbiter camera probe begins raising its orbit towards the sun’s poles, whilst Betelgeuse’s elusive buddy continues to sneak past our best telescopes.Earlier this year, Solar Orbiter started to stretch its orbit over greater latitudes – effectively standing on cosmic tiptoes to catch a glimpse of the Sun’s poles. This week, we have seen the first ever pictures of them, and as solar scientist Steph Yardley tells us, the views will only get better.Meanwhile, Andrea Dupree of the Harvard Smithsonian Center for Astrophysics and colleagues have had time to study new Hubble and Chandra telescope observations of the iconic star Betelgeuse searching for signs of its hypothesised binary companion – dubbed “Betelbuddy”. The papers that appeared on the Arxiv pre-print server have not yet been fully peer-reviewed, but it seems astronomers will have to keep looking.Humans use machines to read gene sequences as best they can, but it takes time and is not perfect because we do not know what all of it means. Of course nature has its own genome reader – the ribosome. It is this that interprets the genetic instructions contained in our DNA and translates them into actual proteins. Viruses, of course, use it too when a cell gets infected. Shira Weingarten-Gabbay has this week demonstrated how scientists can make use of ribosomes too. Working somewhat in reverse, her team have identified many thousands of proteins previously unknown, that could for example provide targets for future vaccines or antivirals should the need arise.Finally, Nanshu Lu and team in the University of Texas at Austin have been working for some years on two-dimensional wearable electronic “E-Tattoos” to monitor health non-invasively through our skin. Their latest work, describes “A wireless forehead e-tattoo for mental workload estimation”.Presenter: Roland Pease
Producer: Alex Mansfield
Production co-ordinator: Jasmine Cerys GeorgePhoto Credit: ESA & NASA/Solar Orbiter/SPICE Team, M. Janvier (ESA) & J. Plowman (SwRI)

Jun 5, 2025 • 44min
Potential fungal 'Agroterror'?
What is Fusarium graminearum and why were scientists allegedly smuggling it into the US? Also, Alpine Glacier collapse and an HIV capitulation.The FBI has accused two Chinese scientists of trying to smuggle a dangerous crop fungus into the US, calling it a potential agro-terrorist threat. But the fungus has long been widespread across US farms, and elsewhere, and is treatable. So what’s going on? Frédéric Suffert, Senior researcher in plant disease epidemiology at France’s National Research Institute for Agriculture, Food and Environment, gives us some insight.Last week, a glacier above the swiss village of Blatten collapsed and up to 12 million tonnes of ice and rock buried the idyllic, yet thankfully all-but evacuated, hamlet below. Daniel Farinotti of the Swiss Federal Institute of Technology explains how it was monitored more than any such event before, and maybe, despite the tragedy, could help inform the science of such events in a warming world.Amongst the latest cuts to scientific funding by the US government, two consortia working at advanced stages of a potential HIV vaccine have been told their funding will not continue. Dennis Burton of Scripps Research describes finding out.The recipient of the Royal Society Faraday Prize 2024 gave his prize lecture last week. Titled Science Under Threat: The Politics of Institutionalised Disinformation, Salim Abdul Karim’s lecture is available on YouTube. Afterwards, he was kindly able to have a chat with Science in Action about his theme. Presenter: Roland Pease
Producer: Alex Mansfield
Production co-ordinator: Jasmine Cerys George(Photo: A hand holding an ear of wheat. Credit: Heather Schlitz/Reuters)

May 29, 2025 • 36min
Thirteen months to a chip off the moon
China is aiming to join the small club of nations who have successfully returned scientific samples of asteroids for analysis on earth, teaching us more about how our and potentially other solar systems formed. Tianwen-2 launched successfully this week, bound for an asteroid known as Kamo‘oalewa, which sits in a very strange orbit of both the earth and the sun, making it a “quasi-satellite”. Last year, scientists including Patrick Michel of the Côte d'Azur Observatory in France, published an intriguing suggestion that Kamo‘oalewa might in fact not be a conventional asteroid, but instead be a small piece of our moon that was ejected when the Giordano Bruno crater formed. In a little over a year from now, we might find out if that is right.Do you have to hold text at arm’s length to read properly? Qiang Zhang, professor of physics at the University of Science and Technology of China, whose team recently published their demonstration of using a technique from radio astronomy but using optical light. Active Optical Interferometry involves using laser beams to achieve resolutions at distances far in excess of conventional imaging with lenses. As his team showed, and as Miles Paggett of Glasgow University admires, they managed to read newsprint sized letters at a distance of over 1.3km.Finally, how did the Inca Empire write things down, and who did the writing? It has been thought that ornate threads of strings and baubles known as khipu are how records were made for business and administration, probably by a decimal code of knots in strings. But the exact purpose, nature and any meaning encoded therein, has eluded scholars for decades. Sabine Hyland, an anthropologist at the University of St Andrews, Scotland, has been studying them for years, and recently was granted access to the records of a village, only the fourth known, to have continued a form of the khipu tradition after the Spanish conquest to this day. She believes that they could even provide us in the modern world with valuable climate data. Presenter: Roland Pease
Producer: Alex Mansfield
Production co-ordinator: Jazz George(A Long March-3B Y110 carrier rocket carrying China's Tianwen-2 probe blasts off from the Xichang Satellite Launch Center on 29 May, 2025 in Sichuan Province of China. Credit: VCG/Getty Images)

May 22, 2025 • 40min
WHO Pandemic Agreement reached
Edyth Parker, a researcher from Nigeria, discusses the origins of the mpox epidemic, highlighting zoonotic spillover and the need for improved genomic surveillance. Jürgen Richt, a veterinary virologist, explores the risks of H5N1 flu potentially infecting pigs, raising concerns about new viral variants. Lucy van Dorp, a geneticist, delves into ancient bacteria evolution, revealing how human activities influenced pathogen lifestyles. Together, they emphasize the urgent need for equitable global health strategies to prevent future pandemics.