Hannah Devlin

Astronomers have identified S301 as the fastest known star in the Milky Way and the closest known star to Sagittarius A*, the galaxy’s central supermassive black hole. Travelling at about 25,000km per second, S301 completes a highly eccentric orbit in 8.7 years and approaches the black hole to roughly 12 times the Earth–Sun distance. Observations from the European Southern Observatory’s Very Large Telescope Interferometer could allow scientists to measure Sagittarius A*’s spin within the next decade, testing general relativity and improving understanding of the Milky Way’s evolution. The star is not expected to cross the black hole’s event horizon.

A study of nearly 2,800 Campylobacter genomes from chickens and wild birds in 30 countries found that the exchange of bacterial strains between the two groups has increased about 100-fold since 1900 as chicken farming intensified. Scientists say the dense scale of modern poultry production is enabling Campylobacter to evolve, including the acquisition of antimicrobial-resistance traits. Because raw chicken is a major source of human infections, the findings raise concerns about food safety, treatment options and the wider public-health consequences of industrial farming.

Orcas in Mexico’s Gulf of California were observed holding dead sunfish while another whale rammed them at high speed, breaking the fish into thousands of fragments. Scientists suggest the coordinated behavior may help younger orcas eat smaller pieces, though it could also be social play, consistent with the species’ known games and cultural fads. The observations demonstrate sophisticated planning and coordination, while raising questions about the effects of wildlife tourism and the need for respectful distances and stronger protections.

A new ancient DNA analysis revealed that the Upton Lovell Shaman, long assumed to be a male Bronze Age metalworker and spiritual figure, was in fact a woman. The findings challenge previous assumptions about gender roles in early metalworking and ceremonial life. Artefacts in the grave, including metalworking tools, fossil sponge cups, and a ceremonial cloak, support her status as a skilled craftsperson. The results, part of a new exhibition at the Francis Crick Institute, underscore how advances in ancient genomics are reshaping understanding of ancestry, identity, and social roles in Bronze Age Britain.

Evidence of declining testosterone and sperm counts has prompted debate among scientists, with some warning of a male reproductive crisis and others arguing that data inconsistencies and metabolic health trends offer more plausible explanations. Obesity and diabetes are widely acknowledged as key drivers of falling testosterone, while environmental contaminants remain under scrutiny but with inconclusive mechanistic evidence. Experts caution against panic and warn that misinformation could drive harmful self-treatment, such as inappropriate testosterone usage that suppresses sperm production. Despite limited diagnostic advances since the 1950s, emerging technologies such as microfluidics, improved sperm DNA assessment and potential lab-grown gametes suggest coming improvements in male fertility treatment. Uncertainty persists, but researchers stress focusing on clear health risks and avoiding alarmist predictions.

Men’s average testosterone levels may have fallen by roughly half over the past 50 years, raising concerns about male fertility and health. Researchers point to rising obesity and diabetes as possible contributors, while also investigating endocrine-disrupting chemicals in household products and global heating. Ian Sample discusses the findings and their reception with science correspondent Hannah Devlin, including calls for further research and action.

Researchers report a 54% decline in men’s total testosterone levels between 1972 and 2019, based on a meta-analysis of six longitudinal studies across multiple countries. Scientists warn of a broader decline in male reproductive health, citing obesity and diabetes as likely contributors, while environmental factors such as endocrine-disrupting chemicals and global heating remain uncertain but possible influences. Some experts argue obesity and diabetes alone could explain the trend, while others call for precautionary measures to reduce chemical exposure. The article also highlights concerns about the growing promotion of testosterone supplements, which can suppress sperm production.

A study of more than 2,000 men in Salt Lake City links exposure to outdoor air pollutants, particularly ozone and nitrogen dioxide, to epigenetic changes in sperm that influence gene activity. Researchers identified 39 DNA methylation changes that may affect fertility, including one in the GNAS gene associated with semen quality and fetal development. Experts note the findings show measurable effects but say further research is needed to determine their clinical significance.

Simon Baron-Cohen says his “extreme male brain” label for autism is misleading despite the underlying science remaining valid. A major donation from philanthropist Lisa Yang will fund new Cambridge research centers focused on improving physical health, life expectancy, diagnosis and quality of life for autistic people. Recent findings from Baron-Cohen’s team suggest heightened cardiovascular risk among autistic individuals, particularly women. The centers will prioritize research shaped by autistic community input, reflecting increasing emphasis on consultation. Rising autism diagnoses in the UK continue, but Baron-Cohen rejects claims of casual overdiagnosis and is piloting GP-based diagnosis to reduce waiting times.

An expanded Met Office extreme heat warning forecasts UK temperatures reaching up to 38C with a chance of surpassing historical June records. Prolonged heat and high humidity pose risks to vulnerable populations, with widespread tropical nights expected and potential impacts on infrastructure, power and water supplies. Health authorities have issued alerts urging hydration, avoidance of peak sun and home-cooling measures. Experts highlight rising mosquito activity and the heightened vulnerability of elderly and low‑income groups. Temperatures are expected to peak midweek before easing by Friday.

A new maternal blood test using non-invasive foetal sequencing can detect thousands of serious genetic conditions by analysing foetal DNA fragments in the mother’s bloodstream. Researchers report detection accuracy comparable to invasive procedures such as amniocentesis, potentially reducing the need for risky tests. Scientists highlight major diagnostic advantages but note risks associated with identifying variants of uncertain significance, which could create anxiety and unnecessary medical follow‑up for parents.

Researchers have identified that Venus flytraps close rapidly when trigger hairs detect movement, causing outer leaf cells to soften and flip the trap shut within a second. Measurements using immobilised leaves and a nanoindenter showed this softening is due to increased cell flexibility rather than water movement, overturning previous assumptions. The findings clarify a mechanism that puzzled scientists since Darwin and highlight plants’ ability to sense and respond quickly to environmental cues.

An analysis by the British Geological Survey identifies millions of homes in London, Essex, Kent and parts of eastern England as increasingly vulnerable to climate‑related subsidence due to hotter, drier summers. Shrinking ground conditions could damage foundations and reduce property values, with signs including structural cracks and sloping floors. Subsidence‑related insurance claims have already risen, and projections indicate up to 1.8 million properties could be affected by 2070 under medium emissions scenarios. Areas such as Camden, Islington and Barnet face the highest risk as climate conditions intensify.

Experiments showed that bumblebees can use tools to solve a problem similar to the classic box‑and‑banana test, challenging assumptions that insects rely solely on instinct. Bees learned to roll a ball beneath an artificial flower to reach a reward and succeeded even in more complex versions requiring memory of the flower’s location. Researchers say the findings reveal flexible problem‑solving abilities in insects with miniature brains, reinforcing evidence of unexpectedly advanced cognition in bees.

A new artificial eggshell developed by Colossal Biosciences is presented as a step toward reviving the extinct New Zealand moa, using a silicone membrane said to replicate natural oxygen exchange. Scientists express skepticism due to the lack of published data, the major genomic gaps resulting from degraded moa DNA, and unresolved ethical concerns about creating genetically modified birds resembling moas. The technology’s scalability for producing such a large species remains unproven, and experts warn that the company’s high-profile announcements often blend scientific advances with promotional claims.

A 59,000-year-old Neanderthal molar from Siberia shows the earliest known evidence of dental treatment, featuring a drilled cavity likely made with a sharp stone tool. Microscopic analysis indicates severe decay and intentional drilling that relieved pressure, suggesting advanced cognitive abilities and medical knowledge. Experiments replicating the technique demonstrated that a stone tool could produce the same grooves and shape. Researchers say the individual survived for some time after the procedure, highlighting both compassion within Neanderthal groups and the patient’s endurance.

A man has produced sperm from testicular tissue frozen before childhood chemotherapy, marking the first successful restoration of sperm production in an adult through transplanted cryopreserved prepubertal tissue. The procedure, carried out in Belgium, demonstrates proof of principle for restoring fertility in patients whose treatment before puberty prevents sperm preservation. The grafts yielded mature sperm after a year, though fertility potential still needs confirmation. Similar trials in the UK are preparing to begin, with more than 3,000 patients worldwide already storing testicular tissue. The findings offer new hope for future biological parenthood among boys who undergo fertility‑damaging treatments.

A small clinical trial found that the radiotracer maraciclatide successfully detected endometriosis in most participants, offering a potential alternative to invasive surgical diagnosis. The tracer highlights tissue forming new blood vessels, enabling earlier identification through Spect-CT imaging. Researchers from the University of Oxford reported high alignment between scan results and surgical findings, with no false positives. Longer diagnostic delays, particularly in England and among ethnic minority women, have underscored the need for improved tools. Serac plans larger phase 3 trials, and the findings may support faster development of new treatments, especially for early-stage peritoneal endometriosis.

A decade-long trial comparing partial meniscectomy with sham surgery found no benefit from the procedure and worse long-term outcomes, including poorer knee function and increased osteoarthritis progression. Researchers concluded that meniscus tears detected by MRI are often incidental and that surgery should generally not be the first-line treatment. While clinical guidelines have shifted toward more conservative management, some orthopaedic organisations still endorse the operation, highlighting the difficulty of discontinuing ineffective therapies.

Additional confidential health records of UK Biobank volunteers were found listed on Alibaba following an earlier major data breach. UK officials, including Patrick Vallance, reported ongoing cooperation with Chinese authorities to remove the posts and warned that more listings may appear. Although the data was de-identified, concerns were raised about the growing risk of re-identification. UK Biobank has faced a series of breaches in recent weeks, including accidental uploads by external researchers, prompting temporary suspension of data access. Public figures criticised the organisation for inadequate protection of sensitive volunteer information, while the government works to determine the scale of the leaks and ensure data removal.

Newly analysed fossilised beaks indicate that ancient octopus relatives reached lengths up to 19 metres and were apex predators in Cretaceous oceans. Distinct wear patterns on the beaks suggest they crushed hard prey including bones and shells, challenging assumptions that large vertebrates dominated marine ecosystems. Researchers identified both previously misclassified and newly uncovered beaks, concluding that species such as Nanaimoteuthis haggarti may have surpassed modern giant squid in size. Evidence of lateralised behaviour suggests advanced predatory strategies. The findings were published in the journal Science.

De-identified health records from 500,000 UK Biobank volunteers were discovered for sale on Alibaba, prompting rapid removal after intervention by the UK and Chinese governments. The breach raised concerns about lax data security, with critics arguing that UK Biobank failed to adequately prevent downloads of raw data. Access for several research institutions was revoked, and Biobank temporarily suspended its research platform to implement additional safeguards. UK officials and experts described the incident as a serious blow to public trust in digital health initiatives.

Curiosity detected several previously unseen organic molecules in a Martian lakebed, suggesting complex material can persist for billions of years despite harsh surface conditions. Researchers say the compounds could originate from ancient life, meteorites or geological processes, but current data cannot determine their source. The discovery strengthens expectations for more definitive analysis from the European Space Agency’s upcoming Rosalind Franklin rover, which will drill deeper and conduct more advanced tests on Martian organics.