Credit: L. Maquet, Observatoire de Paris

In 2013, astronomers discovered two narrow rings around Chariklo, a 250-kilometre-wide minor planet orbiting between Saturn and Uranus, marking the first time rings had been found around such a small body. Nine years later, the James Webb Space Telescope observed the same system during a rare stellar occultation and found that the inner ring had become noticeably more opaque while the outer ring appeared weaker and more transparent. This opposite evolution suggests that Chariklo’s rings are far more dynamic than previously thought, changing on timescales of just a few years rather than remaining stable over centuries, according to a study led by the Institute of Astrophysics of Andalusia and reported by EurekAlert.

A tiny world with giant-planet features

Chariklo, formally known as 10199 Chariklo, is classified as a centaur, a type of icy minor planet that orbits in the outer Solar System between the giant planets. With a diameter of only about 250 kilometres, it is tiny compared to Saturn or Uranus, yet it hosts a ring system that rivals those worlds in complexity. The two rings, designated C1R and C2R, are extremely narrow and lie close to the body, at distances of roughly 390 and 405 kilometres from Chariklo’s centre.Before 2013, ring systems were considered a feature reserved for the four giant planets: Jupiter, Saturn, Uranus and Neptune. The discovery that a small, distant object like Chariklo could sustain dense rings upended that assumption and raised new questions about how such delicate structures form and survive. Were they the result of a recent collision, the breakup of a small moon, or material lifted from Chariklo’s surface by some unknown process? And how could they remain stable in an environment where gravitational tugs from nearby giants and passing objects might be expected to tear them apart?

How astronomers study invisible rings

Chariklo’s rings are too narrow and too far away to be photographed directly, even by the James Webb Space Telescope or the largest ground-based observatories. Instead, they rely on a technique called stellar occultation. When Chariklo passes in front of a background star, the starlight is briefly blocked by the body and its rings as they cross in front of the star. Using fast and precise instruments to measure these tiny drops in brightness, scientists can deduce the width, spacing and opacity of the rings.The 2022 observation marked a major milestone. It was the first stellar occultation specifically predicted and planned for the James Webb Space Telescope. Achieving this required extraordinarily precise knowledge of Chariklo’s orbit, the position of the target star, thanks to data from the European Space Agency’s Gaia mission, and the exact trajectory of JWST as it orbits the L2 Lagrange point about 1.5 million kilometres beyond Earth. At the time of the occultation, Chariklo was moving relative to JWST at just 2.5 kilometres per second, giving the team unprecedented spatial resolution for probing the ring structure.

Opposite changes in the two rings

When the team compared the 2022 JWST data with earlier occultation measurements from the past decade, they found that the two rings were evolving in opposite directions. The inner ring, C1R, was much more opaque, blocking more starlight and probably containing more material or more tightly packed particles than previously. The outer ring, C2R, displayed lower opacity, suggesting it had become more tenuous or less dense over the same period.These changes occurred over less than a decade, a very short time in planetary terms. Until now, scientists had generally assumed that rings around small bodies were relatively stable, persisting with little change over long periods. Chariklo’s behaviour challenges that view and implies that these systems can be surprisingly active, responding to internal dynamics or external influences on human-observable timescales.

What might be driving the changes

The physical origin of the detected changes remains an open question. One possibility is that the rings are undergoing genuine temporal evolution. Collisions between ring particles, gravitational interactions with invisible shepherd moons, or perturbations from Chariklo ’s irregular shape could redistribute material between the two rings or within each ring. Over time, such processes could make one ring denser and another more diffuse.Another possible reason may be the different filters and observation set-ups used in the various occultation campaigns . The JWST observations were taken in specific infrared filters, while the previous ground-based campaigns were in visible or near-infrared wavelengths. If the particles that make up the rings are of different sizes, then the rings can appear to have different opacities when viewed with different wavelengths of light. The study authors note that the observed changes could reflect a combination of real evolution and observational differences, and they call for further monitoring to disentangle these effects.

A new window on ring dynamics

The ability to detect changes in Chariklo’s rings over just a few years opens a new window for understanding how ring systems evolve. If small bodies can host dynamic rings that shift on short timescales, similar behaviour might be found in other minor-planet systems yet to be discovered. This could reshape models of how rings form, how long they last and what mechanisms keep them confined and stable in the face of disruptive forces.For planetary scientists, Chariklo has become a natural laboratory. Its rings are close enough to the central body and narrow enough that subtle changes can be measured with current technology, yet distant enough that they exist in a different gravitational and collisional environment than the rings of Saturn or Uranus. By watching how C1R and C2R change over time, researchers can test theories about particle collisions, wave propagation, confinement by small moons and the role of radiation and micrometeoroid impacts in shaping ring architecture.

A technical and collaborative achievement

The studytitled ‘JWST stellar occultation reveals unexpected changes in Chariklo’s ring system’, published in Science Advances, was led by researchers at the Institute of Astrophysics of Andalusia, part of the Spanish National Research Council. The team designed the project, predicted the occultation, coordinated the JWST observation, analysed the data and interpreted the results. Collaborators from Spain, Brazil, France, Hungary and the United States contributed to ring modelling, statistical analysis and the broader scientific context.Achieving the observation required more than just telescope time. It depended on precise orbital mechanics, accurate star positions from Gaia, and careful planning of JWST’s movements around L2, including station-keeping maneuvers that keep the telescope in its intended orbit. The success of the campaign shows how space-based observatories, in combination with ground-based networks and high-precision astrometry, can probe fine details of distant, faint systems that would otherwise be invisible.

Why Chariklo matters beyond rings

Chariklo’s story is part of a larger shift in how astronomers view the outer Solar System. Once seen as a relatively quiet region populated by static, unchanging bodies, the trans-Saturnian zone is now recognised as dynamic and complex. Centaurs like Chariklo migrate over time, sometimes evolving into short-period comets, sometimes being ejected from the Solar System entirely. Their surfaces can be altered by impacts, outgassing and radiation, and now their ring systems appear capable of changing on observable timescales.As telescopes and techniques improve, more ringed minor planets may be discovered, and existing ones may be monitored more closely. Each new system will add data points to a growing picture of how common rings are, how long they survive and what conditions allow them to persist. Chariklo, once a curiosity, has become a benchmark object for this emerging field.

Looking ahead

The authors emphasise that their results force a rethink of how small-body ring systems form, evolve and maintain stability. Future occultations, ideally with JWST and large ground-based facilities working together, could track further changes in Chariklo’s rings and search for similar behaviour in other objects. Over time, these observations may reveal whether the opposite trends seen in C1R and C2R are part of a cyclical process, a one-time redistribution of material or something more complex.For now, Chariklo stands as a reminder that even in a Solar System that has been studied for centuries, surprises remain. A 250-kilometre-wide world, billions of kilometres from Earth, is hosting a pair of rings that are changing before our eyes, inviting astronomers to watch, measure and refine their understanding of how such delicate structures can exist and evolve in the cold darkness beyond the giant planets.

David Beckham took up beekeeping during lockdown, inspired by his son Cruz.Image credit: Millie Pilkington / Country Life​

David Beckham, the football icon who took up beekeeping during the Covid-19 lockdowns, now produces his own honey at his Cotswolds home, according to The Standard. His hobby comes as experts discuss the potential effects of managed honeybee colonies on wild pollinators. Wildlife filmmaker and National Geographic Explorer Bertie Gregory has suggested that people who want to help bees should consider planting wildflowers instead of keeping honeybee colonies. He explained that cities can have too many beehives, potentially increasing competition for food. His comments highlight concerns about how managed hives may affect wild bees in areas with limited floral resources.

David Beckham’s interest in beekeeping began during lockdown

According to The Standard, David Beckham began keeping bees during the Covid-19 lockdowns and developed the hobby at his Cotswolds property, where he now produces honey.Other celebrities, including Stacey Solomon, Rod Stewart and Ed Sheeran, have also been associated with beekeeping. The growing interest has brought greater public attention to honeybees and the process of producing honey.Honeybees are just one type of bee. Wild bees, including bumblebees and solitary bees, help plants reproduce by carrying pollen between flowers. They have different nesting habits and food requirements.

Bertie Gregory raises concerns about managed beehives

Bertie Gregory, who hosts and narrates Secrets of the Bees, has questioned whether keeping honeybees is always the best way to support wild pollinators.In an interview with The Standard, Gregory encouraged people to plant wildflowers rather than automatically purchasing honeybee colonies. He explained that cities can have too many beehives, putting pressure on food sources that wild bees depend on.Gregory compared buying domesticated honeybees to purchasing chickens to save wild birds. His comments focus on the broader beekeeping trend, rather than establishing that David Beckham’s hives have harmed wild bees.

Honeybees and wild bees compete for food

Honeybees collect nectar and pollen to feed their colonies, while wild bees rely on many of the same resources. When large numbers of honeybees forage in a small area, they may compete with other pollinators for food.The level of competition depends on hive numbers, flower availability and the species living nearby. Areas with abundant flowers may support both managed honeybees and wild bees, while limited food supplies can increase competition.A 2016 study published in Basic and Applied Ecology examined competition between managed honeybees and wild bumblebees. Researchers compared sites with and without added honeybee hives and found that the effects varied according to the surrounding landscape. In landscapes with fewer flower-rich habitats, honeybees could reduce bumblebee densities in some areas.

Research highlights the role of hive density

A 2021 study published in Oecologia examined honeybee and wild bee visits to flowers in Munich, Germany. Researchers found that higher honeybee densities were associated with a shift in flower visits from wild bees to honeybees. The study also reported evidence of competition at several types of flowers.Another study published in Scientific Reports in 2018 examined honeybees and wild bees in a protected Mediterranean scrubland in southern France. Researchers reported that high-density beekeeping was linked to reduced wild bee occurrence and lower nectar foraging success. The effects extended several hundred metres around apiaries.These findings show that large concentrations of managed colonies can affect wild bees in certain environments. The results depend on local conditions and should not be applied to every beekeeping operation.

Why planting wildflowers can help bees

Gregory recommended planting wildflowers to provide food for a wider range of pollinators. Wildflowers produce nectar and pollen, while planting different species that bloom at different times can help provide food throughout the season.Flower planting is one part of pollinator conservation. Bees also need suitable nesting sites, and threats such as pesticides, habitat loss and disease can affect wild populations.Creating flower-rich habitats and protecting nesting areas can help support wild bees and other insects.

What David Beckham’s hobby tells us about bee conservation

David Beckham’s beekeeping hobby has brought attention to the relationship between honey production and pollinator conservation. Honeybees play an important role in agriculture, while wild bees support natural ecosystems and plant reproduction.Gregory’s comments highlight the importance of considering wild pollinators when people decide to keep honeybees. Research from different locations shows that managed colonies can affect wild bees in some circumstances, while other studies have found no direct effect on wild bee diversity.The evidence suggests that local conditions matter when assessing the impact of beekeeping. Planting wildflowers, protecting nesting habitats and supporting native pollinators are practical ways to help a wider range of bee species.

Representative Image of a pair of white dwarfs orbiting closely, surrounded by a cosmic background and X-ray emissions (AI Generated Image)

An international team led by Indian astronomers has identified a pair of white dwarfs locked in an extraordinarily tight orbit that is shrinking faster than that of two other well-known systems of the same type. The binary, known as eRASSU J060839.5–704014 or eRASSU J0608, completes an orbit in just 374.15 seconds, or about 6.2 minutes. Researchers tracked the system’s orbital motion for three and a half years using observations from NASA’s NICER telescope and the Chinese-led Einstein Probe mission, together with archival data from the European Space Agency’s XMM-Newton observatory. Their findings, published in The Astrophysical Journal Letters titled Rapid Orbital Decay in the Ultracompact Double-degenerate Binary eRASSU J060839.5–704014 on August 10, 2026, show that the system is among the most rapidly evolving ultracompact double-white-dwarf binaries currently known. The researchers say its predictable gravitational-wave signal could also make it a promising verification source for future space-based observatories such as the planned Laser Interferometer Space Antenna, or LISA.

The two white dwarfs orbit each other in just 374 seconds

White dwarfs are the dense stellar remnants left behind when stars such as the Sun exhaust their nuclear fuel and shed their outer layers. In an ultracompact binary, two such remnants can orbit one another at an extremely small separation, producing orbital periods measured in minutes rather than days or years. eRASSU J0608 completes one orbit every 374.15013 seconds, equivalent to about 6.24 minutes. The system was first identified as a supersoft X-ray source in observations from eROSITA, the X-ray instrument aboard the Spektrum-Roentgen-Gamma mission. Follow-up observations established that the source was consistent with a double-degenerate ultracompact binary in the foreground of the Large Magellanic Cloud. The short orbital period is accompanied by a strongly modulated X-ray signal. Earlier observations found pulsations at roughly 374 seconds, while the new study used the timing of those X-ray pulses to follow changes in the binary’s orbit over time.

Material from one white dwarf may be striking the other directly

The system belongs to a rare class of ultracompact binaries in which material transferred from one white dwarf can reach its companion without first forming a conventional accretion disc. This configuration is known as direct-impact accretion. The researchers’ X-ray observations support this interpretation. The system produces a supersoft X-ray spectrum, with the new study measuring thermal components corresponding to temperatures of about 126 and 144 electronvolts. Those temperatures are equivalent to roughly 1.5 million and 1.7 million kelvin. The direct-impact interpretation also provides an explanation for the system’s strong X-ray modulation. As material from the donor white dwarf reaches the surface of its companion, the impact region can become extremely hot and emit X-rays. The bright phase changes in temperature during the orbit, which the researchers interpreted as evidence for a structured emitting region with significant temperature differences across it.

Its orbit is shrinking faster than those of HM Cnc and V407 Vul

To measure how the binary is evolving, the researchers combined X-ray timing observations from NICER and Einstein Probe with archival XMM-Newton observations. By connecting these observations over a baseline of about three and a half years, they obtained a coherent timing solution for the system. The measured orbital period is decreasing at a rate of approximately 4.7 × 10⁻¹¹ seconds per second. That may sound tiny, but over astronomical timescales it represents an unusually rapid change for a binary system. The researchers found that the measured orbital decay is greater than that observed in HM Cnc and V407 Vul, two other well-studied ultracompact double-degenerate binaries. The rapid decay is consistent with the system losing orbital energy and angular momentum through gravitational radiation. In their analysis, the researchers assume that gravitational-wave angular-momentum loss is the primary driver of the observed orbital evolution. Under that assumption, they infer a chirp mass of about 0.43 times the mass of the Sun.

The system may be among the most massive of its class

The chirp mass is a parameter that describes a binary’s component masses and plays an important role in determining the evolution and gravitational-wave signal of an inspiralling system. For eRASSU J0608, the inferred value of about 0.43 solar masses places it among the most massive known systems in this particular class, according to the researchers. The authors describe eRASSU J0608 as one of the most rapidly evolving ultracompact double-degenerate binaries currently known. Its unusually fast orbital evolution makes it useful for studying the short-lived stages through which extremely compact stellar binaries evolve. The system is also potentially important for gravitational-wave astronomy. Its orbital period is short enough to place its expected gravitational-wave emission in the low-frequency regime targeted by future space-based detectors rather than the frequency range of today’s ground-based observatories.

eRASSU J0608 could become a verification source for LISA

The researchers say eRASSU J0608 is a promising verification source for future low-frequency gravitational-wave observations. A verification source is a binary whose gravitational-wave signal can be predicted from independent observations, allowing researchers to compare that prediction with what a future gravitational-wave detector actually measures. One mission designed to study low-frequency gravitational waves is ESA’s Laser Interferometer Space Antenna (LISA). The mission will use three spacecraft separated by millions of kilometres to measure tiny changes produced by passing gravitational waves. ESA currently plans LISA for launch in 2035.For eRASSU J0608, however, an important uncertainty remains: its distance has not yet been firmly established. The earlier discovery study placed the system in the direction of the Large Magellanic Cloud and concluded that it lies in the foreground of the galaxy, but determining its distance more precisely would improve estimates of the system’s physical properties and expected gravitational-wave signal. The IUCAA-led team plans to continue observing the binary with X-ray telescopes and search for a visible-light counterpart. Those observations could help researchers determine its distance and component masses more precisely, allowing them to refine predictions for the gravitational-wave signal that future space observatories could measure.

Representative Image of a subalpine meadow shifting from herbaceous plants to shrub-dominated vegetation due to climate warming (AI-generated image)

For 29 years, researchers artificially warmed a subalpine meadow at the Rocky Mountain Biological Laboratory in Gothic, Colorado, to examine how sustained temperature increases affect ecosystems above and below ground. The results, published in the Proceedings of the National Academy of Sciences in February 2026 in a study titled Experimental warming decouples plant-fungal symbiont interactions and leads to a more conservative ecosystem, showed that warming shifted the vegetation from a forb- and graminoid-dominated community towards one dominated by shrubs, while changing the fungal communities associated with plants and soil. Shrubs increased by 150% in warmed plots, while both forbs and grasses declined by about 28%. At the same time, arbuscular mycorrhizal fungal abundance and root colonisation declined, while saprotrophic fungi increased. The researchers concluded that warming had decoupled plant and fungal communities and moved the ecosystem towards a more conservative, shrub-dominated state.

Warming changed the meadow from herbaceous to shrub-dominated

The experiment began in the early 1990s at the Rocky Mountain Biological Laboratory, where researchers used heaters to maintain warmer conditions in experimental plots. Over the 29-year experiment, the warmed plots experienced soils approximately 2°C warmer than ambient plots, while snowmelt occurred 10 to 14 days earlier. When the researchers harvested the experiment in 2019, they found that warming had substantially altered the plant community. Shrubs increased by 150% in warmed plots, while the abundance of forbs and graminoids declined by approximately 28%.Aboveground plant biomass also increased by 64% under warming, while belowground plant biomass did not show a corresponding increase. The researchers interpreted this as a shift in resource allocation towards shoots rather than roots. The study described the resulting community as moving from a forb- and graminoid-dominated ecosystem towards an Artemisia-dominated shrub ecosystem.

The plants also became more conservative in how they used resources

The change in plant composition was accompanied by a shift in plant functional traits. The researchers found that the traits of the warmed plant community moved by about 20% towards more conservative values, rather than the more acquisitive strategy associated with the original herbaceous community. In ecological terms, acquisitive plants tend to invest in rapid resource acquisition and growth, while conservative strategies are associated with retaining resources and using them more slowly. The researchers interpreted the shift as evidence that warming was moving the meadow towards a more conservative resource-use strategy.The change was also reflected in the soil. Plant-available phosphorus increased under warming, while bulk soil enzyme activity decreased by 10%. The researchers suggested that the lower enzyme activity was likely related to the more resistant plant material produced by the increasingly shrub-dominated community. Importantly, 29 years of warming did not change the amount of soil organic matter measured in the experiment.

Mycorrhizal fungi declined as the plant community changed

The biggest belowground change involved fungi that normally form beneficial associations with plant roots. Arbuscular mycorrhizal fungi help plants obtain nutrients from soil in exchange for carbon from their hosts. The researchers found that the relative abundance of arbuscular mycorrhizal fungal sequence reads in soil was 48% lower in warmed plots. Microscopic measurements of individual plant roots showed a separate 17% decline in AM fungal colonisation.Septate root colonisation also declined, with the study reporting an overall reduction of 17% to 20% in the root-associated fungal measures examined under warming. At the same time, soil saprotrophic fungi, which are involved in decomposition, increased by approximately 10%. The researchers found that plant and mycorrhizal fungal communities were strongly associated under ambient conditions but became decoupled under warming. By contrast, the relationship between plants and saprotrophic fungi became stronger.

The researchers linked the fungal changes to the changing plant community

The study found that warming changed plant composition most strongly, followed by changes in fungal composition. The researchers therefore examined whether the underground changes were occurring alongside the transformation of the vegetation above ground. They found that the decline in forbs and graminoids was associated with the reduction in arbuscular mycorrhizal fungi. However, the authors explicitly noted that the experiment’s single sampling point could not establish whether the plant changes caused the fungal changes or whether the relationship worked in the opposite direction.What the researchers could show was that the two communities had become less closely coordinated under long-term warming. They described this as a decoupling of above- and belowground communities. The resulting ecosystem had higher plant-available phosphorus, lower mycorrhizal association and greater connections between plants and saprotrophic fungi. The authors interpreted these changes as evidence of a shift towards a more conservative nutrient and carbon economy.

Earlier snowmelt may add another layer to the problem

The 29-year warming experiment also produced earlier snowmelt, with warmed plots melting 10 to 14 days earlier than ambient plots. Separately, the research team has been studying how the timing of snowmelt affects plant-fungal interactions. In a 2023 experiment at the same research site, researchers advanced snowmelt by about two weeks in 5 plots. They found that mycorrhizal fungal growth advanced by about 1 week, while they did not observe a corresponding change in plant-root growth.

A device that can detect particles arriving from space does not necessarily require a multimillion-dollar laboratory. A compact detector developed by physicist Spencer Axani began as a low-cost student project and has since grown into a tool used for particle-physics research, education and high-altitude experiments. The University of Delaware detailed its latest developments in September, while earlier accounts in Physics Today and Fermilab/SLAC’s Symmetry documented how the project evolved from Axani’s work at MIT into the CosmicWatch programme.The device, called CosmicWatch, detects muons, short-lived subatomic particles produced when high-energy cosmic rays collide with atoms in Earth’s atmosphere. Those collisions generate cascades of secondary particles, some of which reach the ground and pass through buildings, rock and even the human body. Muons travel extremely close to the speed of light, making them useful messengers of what happens when cosmic radiation interacts with Earth’s atmosphere. Unlike ordinary light, however, they cannot be seen directly. A detector such as CosmicWatch converts their passage into measurable electrical signals.

How a $100 device detects particles from space

CosmicWatch is small enough to be handheld and costs about $100 in components. Its design combines a plastic scintillator with a silicon photomultiplier, electronics that process the tiny flashes of light produced when a muon deposits energy in the detector. The latest v3X design can record events to a microSD card or stream measurements through USB, while also logging information such as temperature, pressure and acceleration.The affordability is significant because traditional particle detectors can involve much larger and more expensive equipment. The original CosmicWatch research paper described the detector as a self-contained, portable instrument that students could build and use themselves, with a first build taking a novice roughly four hours.That approach also makes the detector useful outside conventional laboratories. Students can assemble one, collect measurements and then investigate how the number of detected muons changes with altitude, shielding or other environmental conditions.From an MIT project to a research toolAxani started developing the detector while he was a graduate student at MIT. The initial motivation was more closely tied to large-scale neutrino research, where detecting atmospheric muons can help researchers distinguish them from the neutrinos they are actually trying to study.The idea gradually moved in a different direction: instead of building another expensive instrument for a specialised facility, Axani and his collaborators developed a version that could be made cheaply enough for students and small research projects.The project became CosmicWatch and has continued to evolve. Its current v3X version adds environmental sensors, improved data collection and coincidence capabilities, allowing multiple detectors to be used together to reduce background events.

Why scientists care about muons

Muons are more than proof that cosmic radiation is passing overhead. Because they are energetic and highly penetrating, researchers can use them to investigate both cosmic-ray processes and structures on Earth.Muon measurements can help scientists study the showers produced by cosmic rays and understand the properties of the particles that initiated them. The same basic principle has also been used in muography, a technique that creates images by measuring how many muons pass through an object.That has applications ranging from archaeology to geology. The ability of muons to travel through substantial amounts of material makes them particularly useful when conventional imaging methods cannot easily penetrate a structure.

The detector can go where laboratories cannot

One of CosmicWatch’s most interesting advantages is its portability. Similar detectors have already been incorporated into high-altitude balloon experiments, where researchers can observe how cosmic-ray activity changes as the payload climbs through the atmosphere. Independent balloon experiments have previously carried CosmicWatch detectors to altitudes exceeding 60,000 feet.The University of Delaware has also described a more recent balloon experiment in which a modified detector was taken to around 100,000 feet. At those altitudes, the changing atmospheric environment provides an opportunity to study how cosmic-ray particle rates vary with elevation.The technology is also being used in research settings, including detector experiments studying rare particles and dark matter. A future version is being explored for measuring primary cosmic rays in rockets and spacecraft.

A pocket detector with a much bigger ambition

The project has also opened the possibility of creating a distributed network of inexpensive cosmic-ray detectors. Instead of measurements coming from a handful of specialised facilities, detectors placed in different locations could potentially contribute observations to a shared database.That would turn what began as an inexpensive teaching instrument into something closer to a citizen-science network, allowing students and researchers in different parts of the world to compare cosmic-ray measurements.CosmicWatch’s significance, then, is not simply that it makes particle detection cheaper. Its compact design lowers the barrier to experimenting with a part of physics that normally feels inaccessible, giving students a way to detect particles from cosmic-ray interactions with equipment small enough to sit on a desk.

PC: Dr Joshua Copping/ University of Cambridge

Solar farms can provide renewable electricity while also supporting wildlife when managed carefully. A study of six solar farms in the East Anglian Fens found that bird abundance and species richness varied with site management. Researchers surveyed 23.2 km of transects across the solar farms and 15.2 km across arable farmland, recording birds seen or heard within 100 m. Mixed-habitat solar farms, where grass was cut or grazed less often, and wildflowers, hedgerows, or trees were present, supported more birds and species than simple-habitat solar farms and arable land. According to the research published by the University of Cambridge and The Royal Society for the Protection of Birds (RSPB) in Bird Study, titled ‘Solar farm management influences breeding bird responses in an arable-dominated landscape’, bird populations varied depending on how the solar farms were managed.

How did researchers survey birds across solar farms and nearby arable land

Researchers surveyed six solar farms in the East Anglian Fens and compared them with nearby arable land. The survey covered 23.2 km of solar farm transects and 15.2 km of arable farmland. Solar farms were divided into two types. Simple habitat solar farms were intensively managed, with grass around panels cut or grazed so the grass cover stayed short during summer. Mixed habitat solar farms had less frequent cutting or grazing, allowing taller grass and wildflowers, while hedgerows or trees occurred along boundary fences. Researchers surveyed arable land located 0.95 to 1.6 km from each solar site.

PC: Ben Andrew/University of Cambridge

Mixed-habitat solar farms supported more birds and species

Across all sites, researchers recorded 830 individual birds from 44 species. Wood Pigeon was the most common species, with 152 individuals recorded across arable land and solar farms. Mean abundance was highest in mixed-habitat solar farms for 34 of the 44 species. As per the study results, predicted abundance was 35.1 birds per 4 hectares in mixed-habitat solar farms, compared with 17 birds per 4 hectares in simple-habitat solar farms and 11.9 birds per 4 hectares on arable land.Species richness followed a similar pattern. Mixed-habitat solar farms had 13.5 species per 4 hectares, compared with 5.3 in simple-habitat solar farms and 5.5 on arable land. The overall difference in bird abundance across the three categories was statistically significant.

How habitat structure influenced bird communities

The study found that differences in management were linked to differences in bird abundance and species richness. Mixed-habitat solar farms appeared to provide greater structural diversity than nearby arable land, with taller grass, wildflowers and woody boundary features creating a more varied habitat.By contrast, simple-habitat solar farms had only marginally greater structural diversity than arable fields and showed similar levels of bird abundance and species richness.Researchers also recorded more woodland generalist species in mixed-habitat solar farms than in arable land and simple-habitat solar farms, which they associated with hedgerows and boundary trees.

Why management matters for solar farm biodiversity

The researchers indicate that solar farms in nature-depleted, arable-dominated landscapes can increase bird abundance and diversity when they are managed with biodiversity in mind, especially through mixed habitat management.They note that careful planning is still needed when deciding where solar farms should be located because field-scale solar is generally incompatible with continued crop production.Within suitable locations, mixed habitat management can create additional habitat compared with intensively managed farmland. The study also places these findings in the context of continued solar expansion in Britain and growing public concern about effects on biodiversity. Its results indicate that management choices, including less frequent cutting or grazing and maintaining diverse habitats, can influence how solar farms function for birds in agricultural landscapes.

High in California’s Sierra Nevada, a conservation project changed the future of a disappearing amphibian. In 2001, staff at Sequoia and Kings Canyon National Parks began removing non-native trout from selected lakes and streams, restoring water bodies that had historically been home to mountain yellow-legged frogs but were naturally fishless. By 2011, nearly 44,000 trout had been removed from 19 lakes, including complete removal from nine. The results were striking: surveys in three restoration lakes recorded an increase from nearly 190 frogs and tadpoles to more than 18,800. The National Park Service says the project helped restore ecological balance and placed the frog population in a stronger position to face other threats, including deadly fungal disease.

A fish introduced into fishless lakes

The mountain yellow-legged frog is native to the high country of the Sierra Nevada. These frogs evolved in lakes, ponds and streams where fish were naturally absent.That detail is important. For thousands of years, the frogs’ life cycle developed without the pressure of predatory trout. Tadpoles could grow in shallow water, young frogs could move around the edges of lakes and adults could reproduce without constantly avoiding fish.The situation began to change when people introduced trout into high-elevation water bodies. From 1870 to 1988, several non-native trout species were stocked in lakes, ponds, marshes and streams across Sequoia and Kings Canyon National Parks. The National Park Service says these included golden, rainbow, golden-rainbow hybrid, brook and brown trout.The fish were introduced partly to create recreational fishing opportunities and attract visitors. But the stocking programs altered ecosystems that had developed without fish.Trout did not simply become another species in the food web. They became powerful new predators in places where mountain yellow-legged frogs had few natural defences against them.

Why the frogs declined

Trout affect mountain yellow-legged frogs in several ways. They eat tadpoles and small frogs, compete with frogs for insects and force the amphibians into smaller, lower-quality areas.The presence of fish can also separate frog populations. When trout occupy lakes and connecting streams, frogs may be pushed into isolated ponds or narrow areas where they have fewer options for feeding, breeding and escaping environmental stress.The National Park Service reports that mountain yellow-legged frogs have disappeared from 92 per cent of their historic range in the Sierra Nevada. Both recognised species—the mountain yellow-legged frog, Rana muscosa, and the Sierra Nevada yellow-legged frog, Rana sierrae, have faced severe declines.Non-native trout were not the only danger. Chytridiomycosis, a fungal disease that attacks the skin of amphibians, also affected frog populations. Infected frogs can die because the disease interferes with essential skin functions.The combination was especially damaging. Trout reduced frog numbers and restricted their habitat, while disease threatened the populations that remained. By 2014, both species had been listed as endangered under the federal Endangered Species Act.

The restoration effort begins

In 2001, park staff began removing trout from selected waters. The work used large nets and electrofishing equipment.Gill nets could capture fish in lakes, while electrofishers temporarily stunned fish so that crews could collect them. These methods allowed conservation teams to target specific water bodies without applying the same treatment across every lake in the parks.The objective was not to eliminate trout from the entire Sierra Nevada. Instead, the project focused on restoring selected ecosystems where removing non-native fish could provide immediate benefits for native species.By 2011, nearly 44,000 fish had been removed from 19 lakes. Trout were completely removed from nine of those lakes, according to the National Park Service.The work was demanding. High-elevation lakes are often remote, and crews had to transport equipment across rugged terrain. The process also required repeated visits because even a small number of remaining fish could eventually reproduce and rebuild a population.Removing the first wave of fish was only one part of the project. Conservation workers continued targeting the remaining trout to prevent the restored lakes from being recolonised.

A remarkable frog rebound

The clearest sign of success came from Upper LeConte Canyon, a remote area containing lakes and streams where mountain yellow-legged frogs once lived.Park staff conducted summer surveys in three restoration lakes. In 2001, when fish removal began, the surveys recorded nearly 190 frogs and tadpoles. By 2004, after most of the trout had been removed, the number had risen to more than 18,800.That represents an increase of roughly 10,000 per cent, according to the National Park Service.The figure includes both adult frogs and tadpoles, making it a measure of the wider frog population rather than only breeding adults. Even so, the change was dramatic. In just a few years, the lakes went from supporting a small and vulnerable amphibian population to holding thousands of frogs and tadpoles.From 2005 to 2011, as staff removed the last few fish, the frog population stabilised. Numbers varied, but surveys continued to show increases ranging from 1,900 to 6,000 per cent compared with the earlier period.More than 2,000 frogs also moved into two nearby lakes. That movement suggested the restored habitat was doing more than supporting survival. It was helping the frogs expand into areas where they had previously been absent or severely reduced.

Restoring an entire ecosystem

The project was designed to help frogs, but its benefits extended across the aquatic ecosystem.Trout are efficient hunters. They eat aquatic insects, zooplankton and other amphibians, as well as frog tadpoles and young frogs. When trout are removed, more food becomes available to native species.A lake without introduced fish can support a different balance of organisms. Insects and small aquatic animals can increase, creating more feeding opportunities. Tadpoles may have a better chance of reaching adulthood, and frogs can occupy a wider range of habitat.The changes can also affect animals higher in the food chain. Frogs are an important link between small organisms and larger predators. They eat insects and other small prey, while snakes, birds and mammals may feed on frogs.The National Park Service uses the food chain to explain why the decline of frogs can affect the wider natural system. Removing one important species can reduce food availability for other animals and disrupt ecological relationships.In this sense, trout removal was not simply a fish-management project. It was an attempt to restore the natural functioning of high-elevation lakes.

A careful, selective approach

The restoration effort did not mean that every trout in the national parks would be removed.The National Park Service’s final restoration plan proposed treatments in selected water bodies where non-native fish had caused significant harm to native species and ecosystems. Physical methods included gill netting, electrofishing, trapping and disturbing trout spawning areas. In places where physical treatment was not practical, the plan also considered the use of rotenone, a fish-control chemical.The plan identified a maximum of approximately 52 water bodies and 15 miles of streams for physical treatment, along with additional water bodies and stream sections for possible piscicide treatment.At the same time, non-native trout populations would continue to exist in hundreds of other water bodies and many miles of streams in the parks. The plan stated that self-sustaining trout populations would remain in 465 water bodies after the planned treatments.This distinction matters. The goal was not to remove recreational fishing opportunities everywhere. It was to protect selected native ecosystems and species in places where introduced fish had caused severe ecological damage.

Why long-term monitoring matters

Removing trout produced a rapid increase in frogs, but researchers still needed to monitor what happened next.A population can grow quickly after a major threat is reduced, but disease, drought, habitat changes and food shortages can still affect its future. Surveys help scientists determine whether the recovery is stable and whether frogs are reproducing successfully over multiple years.Regular monitoring also helps identify whether fish have returned. A single undetected trout can potentially reproduce, especially if it reaches a suitable spawning stream or shoreline.Park staff conduct surveys during the summer season, when frogs, eggs and tadpoles are easier to observe. Visitors hiking in Upper LeConte Canyon may hear frogs splashing into lakes and streams, see adults laying eggs or observe thousands of tadpoles in warming water.These observations connect scientific work with public awareness. A restored ecosystem becomes easier to value when visitors can see evidence of recovery for themselves.

Recovery amid continuing threats

The frog rebound was significant, but it did not remove every danger.Chytridiomycosis remains a serious threat to mountain yellow-legged frogs. The disease can devastate populations even in lakes where trout are absent. Climate conditions may also affect shallow ponds and lakes, particularly when drought causes breeding habitat to shrink or disappear.By reducing predation and competition from trout, conservation workers gave frogs a better chance of coping with these other pressures. A larger, more widely distributed population is generally less vulnerable than a small group confined to one or two isolated sites.The National Park Service says the restored population is now in a much stronger position to face threats such as disease.That does not mean the frogs are safe. It means the conservation action improved their starting point. Instead of trying to recover from the edge of disappearance, the population has more individuals, more occupied habitat and greater potential to withstand future challenges.

A lesson from the Sierra Nevada

The mountain yellow-legged frog project demonstrates how human actions can damage an ecosystem—and how carefully targeted intervention can help repair it.Trout were introduced with the intention of creating recreational fishing opportunities. But in naturally fishless lakes, the fish altered relationships that had developed over thousands of years. Frogs declined, insects and other aquatic organisms faced new pressures, and the wider food web changed.The response required research, difficult fieldwork and years of monitoring. Between 2001 and 2011, nearly 44,000 trout were removed from 19 lakes. In three restoration lakes, frogs and tadpoles increased from about 190 to more than 18,800.The recovery is a reminder that conservation is not always about protecting nature from outside. Sometimes, it involves undoing a well-intentioned change that created an imbalance.High in the Sierra Nevada, removing non-native trout allowed an endangered native amphibian to reclaim part of its former world. The return of thousands of frogs shows what can happen when a damaged ecosystem is given the right conditions to heal.

Carbon dioxide is abundant but chemically inert, which makes it difficult to turn into useful polymers. A study describes a closed-loop platform that uses carbon dioxide with bicycloalkanes to make high-performance, recyclable polyesters. They used bicyclic butane, or BCB, and bicyclic pentane, or BCP, monomers in a direct alternating copolymerization. A simple organic catalyst initiated the process, producing high-molar-mass polyesters with up to 50 mol% carbon dioxide incorporation. The resulting materials have defined backbones and tailorable thermal and mechanical properties. The study published by Colorado State University, as well as collaborators from Northwestern University, in Nature titled ‘Alternating CO2 and bicycloalkane copolymerization to circular polyesters‘ demonstrates selective depolymerisation and repolymerization, allowing the materials to undergo circular lifecycles.

How researchers used carbon dioxide to make new polyesters

Researchers developed the polyester platform to address a difficulty in using carbon dioxide for polymer production. Previous approaches have generally relied on copolymerization with reactive comonomers and catalysts, but making polyesters from carbon dioxide has remained challenging. The study uses bicycloalkanes instead, specifically bicyclic butane and pentane. These monomers undergo direct alternating copolymerization with carbon dioxide.The reaction is initiated by a simple organic catalyst and proceeds in a perfectly alternating manner. This produces high-molar-mass polyesters with a maximum of 50 mol% carbon dioxide incorporation. Their backbones are architecturally defined, while the in-chain ring structure allows the thermal and mechanical properties to be adjusted through monomer design. This design addresses the difficulty of incorporating carbon dioxide into polyester backbones.

PC: Wikipedia

How the new polyesters can be broken down for recycling

The resulting polyesters combine defined molecular structures with different material properties. According to the study, the in-chain ring structure enables tailorable thermal and mechanical properties, allowing the polyester structures to be varied through the bicycloalkane monomers used. The BCB-CO2 polyesters showed exceptional thermal and hydrolytic stability across the full pH range. The researchers also examined their end-of-life behaviour through selective depolymerisation.Under bulk and base-catalysed conditions, the BCB-CO2 polyesters could be depolymerised to regenerate pure BCB monomers in more than 90% isolated yield. The BCP-CO2 polyesters could also be selectively depolymerised, producing bicyclolactones rather than the original BCP monomers. The products reflect the distinct chemistry of the two monomers during recycling in practice.

The polyesters can be repeatedly recycled into reusable building blocks

A key part of the study was showing that the materials could move through repeated production and recovery steps. The researchers carried out sequential depolymerisation–repolymerization cycles to establish circular lifecycles for BCB/BCP-CO2 high-performance polyesters. For the BCB system, selective depolymerisation regenerated the BCB monomer and carbon dioxide. The study also describes the proposed depolymerisation mechanism for this process. For the BCP system, selective depolymerisation generated bicyclolactone monomers.Those bicyclolactones were then re-polymerised to reform polyester, followed by another depolymerisation step. These experiments demonstrate chemical circularity through repeated conversion between polymer and recoverable molecular building blocks, rather than treating the polyester as a material with only one use.

What makes carbon dioxide-based polyesters suitable for chemical recycling

The researchers describe the work as a closed-loop carbon dioxide-based polyester platform that combines material performance with chemical recycling. The copolymerization reaches high molar masses while incorporating as much as 50 mol% carbon dioxide into the polyester. The study reports especially high thermal and hydrolytic stability for BCB-CO2 polyesters, alongside selective recovery of BCB monomers at more than 90% isolated yield.BCP-CO2 polyesters follow a different recycling pathway and produce bicyclolactones during depolymerisation. Together, the polymerisation and recovery steps establish circular lifecycles for these high-performance polyesters. The platform connects carbon dioxide incorporation with polymer properties and recovery.

Astronomers have reported the first direct detection of radio emission from an exoplanet, tracing the signals to the young gas giant β Pictoris b, located approximately 64 light-years from Earth. Using South Africa’s MeerKAT radio telescope, researchers identified recurring radio bursts and localised their source to the planet rather than its host star. The emission is believed to be linked to auroral activity generated by the planet’s magnetic field. The observations also helped scientists estimate the magnetic field strength in the region producing the radio waves. The discovery offers a new method for studying magnetic fields beyond the Solar System and could provide insights into the internal processes of young, massive gas giants.

Astronomers trace radio signals to a distant exoplanet

A research team led by Kevin Ortiz Ceballos at the Center for Astrophysics Harvard & Smithsonian observed the β Pictoris planetary system during four observing sessions across two frequency bands. They detected faint, repeating radio bursts but initially could not determine whether the signals originated from the host star or one of its planets. To identify the source, the researchers compared their radio images with the precise positions of distant quasars, which served as fixed reference points. The resulting analysis showed that the radio emission aligned with β Pictoris b, supporting its identification as the source.Two of the radio bursts occurred approximately eight hours apart. This interval is close to the planet’s estimated rotation period of around eight to nine hours, providing additional evidence that the emission could be connected to its rotating magnetosphere.

Auroras may be producing the radio signals

The researchers linked the emission to auroral activity associated with β Pictoris b’s magnetic field. Auroras occur when energetic charged particles move along magnetic field lines and interact with a planet’s upper atmosphere. On Earth, this process produces the northern and southern lights. At β Pictoris b, the team believes that energetic electrons moving through the magnetic field generate radio waves through a process called electron cyclotron maser emission. This mechanism is also associated with radio emissions detected from planets in our Solar System.

Radio frequencies reveal the magnetic field

The frequency of electron cyclotron maser emission is related to the magnetic field strength in the region where the radiation originates. Based on the observed radio signals, the researchers estimated that the magnetic field at the emission site is at least 1,250 gauss, or 1.25 kilogauss. This is considerably stronger than Jupiter’s overall magnetic field. The estimate applies to the area producing the radio waves and does not represent a direct measurement of the magnetic field across the entire planet.

Discovery offers clues about young gas giants

β Pictoris b is a young, massive gas giant, making it a valuable target for studying how planetary magnetic fields develop. These fields are generated by processes inside planets and influence their interactions with charged particles and stellar winds. The researchers said their findings are consistent with theoretical predictions for the magnetic fields of young giant planets. Studying the planet’s radio emission could help scientists test these models and learn more about its internal structure.

A new method for studying distant planets

Radio observations can provide information that is difficult to obtain through conventional imaging. By examining the frequency, polarisation and location of radio emission, astronomers can investigate magnetic conditions around distant planets. The localisation of the signals to β Pictoris b offers a way to distinguish planetary emission from radio activity produced by the host star. Future observations could determine whether similar auroral radio signals occur around other exoplanets.

Findings follow earlier radio searches

Astronomers have previously searched for radio emission from exoplanetary systems, but identifying the precise source has remained a challenge. Signals detected from a planetary system may originate from the host star instead of a planet. Earlier observations of β Pictoris b, including a 2024 search using the upgraded Giant Metrewave Radio Telescope, did not report a detection from the planet. The latest research uses positional measurements to associate the radio emission with β Pictoris b.The research paper was posted on the arXiv preprint server on September 15, 2026, and has not yet undergone formal peer review. The findings represent the research team’s reported results and could be examined further through independent observations. Additional data may help confirm the radio source, clarify the relationship between the bursts and the planet’s rotation, and refine the estimate of its magnetic field.

Pet cats may spend much of their time close to home, but their hunting can have a large local effect on wildlife. Researchers worked with citizen scientists to track 925 pet cats from six countries and examined where the animals moved and what types of prey the cats kill. The cats had remarkably small home ranges, with an average of 3.6 hectares, and most used mainly disturbed habitats. Owners reported that their pets killed an average of 3.5 prey each month. According to the research published in Animal Conservation titled ‘The small home ranges and large local ecological impacts of pet cats’, the ecological impact was 14.2 to 38.9 prey per hectare per year for each cat. The study found that these effects were concentrated within about 100 metres of cats’ homes.

How did researchers track the movement of 925 pet cats using GPS

The study tracked 925 pet cats from six countries using GPS data collected with the help of citizen scientists. Researchers combined information on the cats’ movements with reports from owners about prey that their pets killed. The tracked cats had remarkably small home ranges, averaging 3.6 ± 5.6 hectares. Only three cats had home ranges larger than 1 square kilometre. The researchers also found no relationship between home range size and the presence of larger native predators, including coyotes. Most cats used primarily disturbed habitats, with 75% of the cats using these areas for 90% of their activity. These results showed that the cats generally stayed close to the places where they lived across the landscapes they occupied during tracking.

PC: Wikipedia

How much wildlife did pet cats kill near their homes

The researchers found that pet cats’ hunting was concentrated close to their homes rather than spread across large areas. Their ecological impact was estimated at 14.2 to 38.9 prey per hectare per year for each cat. Owners reported that their cats killed an average of 3.5 prey items each month. The study notes that cats do not always bring their prey back home, so the researchers adjusted the prey counts to estimate the total number killed.Although pet cats kill fewer prey per day than wild predators because they receive food from people, their small home ranges concentrate their hunting in a limited area.

Pet cats spent most of their time near homes and neighbourhoods

Most of the tracked cats spent their time in disturbed habitats rather than natural areas. The study reported that 75% of the cats used primarily disturbed habitats, and these areas accounted for 90% of their habitat use. This pattern matters because pet cats are common around homes and neighbourhoods, where their hunting activity is concentrated. The researchers found that the ecological effect of pet cats was greater than that of native predators when considered across the areas where cats are densely distributed. The study described this as a result of the high density of pet cats in neighbourhoods. Their movements remained small, but many cats could be hunting within the same local landscape.

How can pet cats affect wildlife more than native predators

The study indicated that pet cats can have a large local ecological impact even though individual cats usually occupy small areas. Their home ranges were generally small, and most hunting occurred near their homes. The researchers estimated that the combined effect of pet cats around the world was greater than that of native predators, with the impact that concentrated around residential areas. The study also noted that only three tracked cats ranged over more than 1 square kilometre, showing how uncommon large home ranges were among the tracked animals.

Incendiamoeba cascadensis can reproduce at 145°F, setting a heat-tolerance record for complex life. Image: NPR/Felix Mikus.

Scientists have discovered a previously unknown amoeba in the geothermal streams of California’s Lassen Volcanic National Park that can reproduce at temperatures reaching 145°F (63°C). Named Incendiamoeba cascadensis, the organism has set a new heat-tolerance record for known eukaryotic life. It can remain mobile at approximately 147°F (64°C) and survive brief exposure to even higher temperatures. Published in Cell on September 22, 2026, the study explores how complex cells adapt to extreme heat and offers new insights into the environmental limits of life.

Fire amoeba discovered in California

Researchers collected water and sediment samples from geothermal streams in Lassen Volcanic National Park between 2023 and 2025. They cultivated the microorganisms in a laboratory and examined them under a microscope. Beryl Rappaport, a microbiologist at Syracuse University and the study’s lead researcher, identified an unfamiliar organism displaying characteristic amoeba movement. Further testing established that it was a new species, which the team named Incendiamoeba cascadensis. The name refers to the organism’s heat tolerance and its discovery in the Cascade mountain range region.

Amoeba sets new heat-tolerance record

The researchers observed the amoeba reproducing at temperatures reaching 145°F (63°C). It divides through mitosis, the process in which one eukaryotic cell produces two daughter cells. The discovery extends the known temperature limit for eukaryotic growth, previously estimated at approximately 140°F (60°C). Eukaryotes include organisms such as animals, plants, fungi and many single-celled species whose cells contain a nucleus and specialised internal structures. The amoeba can remain mobile at around 147°F (64°C) and recover after brief exposure to temperatures of approximately 158°F (70°C), although it does not reproduce normally at that temperature.

How the amoeba survives extreme heat

Extreme heat can damage proteins and destabilise cell membranes. To understand how the amoeba withstands these conditions, researchers studied its genome and examined its behaviour at different temperatures. The findings suggest that the organism has adaptations that help protect its proteins and membranes. It can also change its shape and movement patterns in response to rising temperatures. At higher temperatures, the amoeba forms a protective structure that helps it withstand short periods of extreme heat. However, scientists have not yet identified the precise mechanisms responsible for its heat tolerance. Further research will be needed to understand how its cellular components remain stable.

Why bacteria and archaea tolerate higher temperatures

The fire amoeba is the most heat-tolerant known organism among complex life, but some bacteria and archaea can survive at much higher temperatures. These organisms generally have simpler cellular structures and lack a membrane-bound nucleus. Certain archaea found in extreme environments, including deep-sea hydrothermal vents, can grow at temperatures above 100°C (212°F). Comparing these organisms with Incendiamoeba cascadensis could help scientists understand the different ways cells adapt to extreme heat. The amoeba demonstrates that eukaryotic organisms can also develop adaptations that allow them to survive in unusually hot environments.

Discovery may expand research into life’s limits

The discovery could help researchers investigate the limits of life on Earth and guide studies of potential life beyond our planet. Organisms that thrive in extreme conditions are known as extremophiles. Angela Oliverio, a microbiologist at Syracuse University and an author of the study, said the finding highlights the importance of exploring unusual environments. The researchers believe other heat-tolerant organisms may remain undiscovered in geothermal habitats. The amoeba could also provide insights into biotechnology, particularly in the study of heat-stable proteins and enzymes. However, any practical applications would require further research. The team plans to compare the fire amoeba with related species to investigate how its heat tolerance evolved.

Nasa astronaut and flight engineer Kate Rubins checks out radish plants growing on the space station as part of an experiment to evaluate nutrition and taste of the plants (Image: Nasa)

Researchers from Nasa Kennedy Space Centre and partner institutions Noetic Strategies, Amentum, Bennett Aerospace and Sierra Space have published the first microbial analysis of crops grown in a substrate-free system aboard the International Space Station. The study, ‘Microbial community characterisation of multi-crop growouts in the XROOTS aeroponic-hydroponic system on the International Space Station,’ led by Christina L. M. Khodadad and colleagues, examined lettuce, mizuna mustard, wheat, radish, tomato and pea plants grown in the eXposed Root On-Orbit Test System (XROOTS). Here’s what they found about the microbes living on and in these space-grown crops.

Testing an aeroponic-hydroponic system ‘XROOTS’ on the ISS

XROOTS is an aeroponic-hydroponic nutrient delivery system developed by Sierra Space to test whether crops could be grown without soil or other solid media, a method that could reduce the cargo mass needed for long-duration missions to the Moon and Mars. Launched to the ISS in February 2022, the system used a combination of aerosol misting and nutrient-solution flow to deliver water directly to plant roots across four growouts between June and October 2022. Researchers harvested mature tissue from mizuna mustard, radish and lettuce in growout two, wheat and lettuce in growout three, and pea and tomato plants that were grown through to fruiting by growout four.

What the microbial counts revealed across these six crops

Bacterial counts in the nutrient solution ranged from 65 to 3,800 colony-forming units per millilitre, and counts were consistently lower in the upper leaf sections than in the lower leaves, wick material and roots across every plant type tested. Tomato fruit and pea pods had the lowest average microbial counts of all the tissue types sampled. Crucially, all screening tests for foodborne pathogens, including E. coli, Salmonella and Staphylococcus aureus, came back negative, and the bacterial counts detected on the edible portions of the ISS-grown crops fell within the ranges typically reported for the same produce grown on Earth.

A preflight view of the XROOTS hardware. The eXposed Root On-Orbit Test System (XROOTS) investigation uses hydroponic and aeroponic techniques to grow plants without soil or other growth media (Image: Nasa)

Comparing microbial diversity with past ISS experiments

Genetic sequencing of the 16S rRNA gene and fungal ITS region showed that microbial diversity was consistently lower in leaf tissue than in root tissue, a pattern also seen in terrestrial agriculture. Pseudomonas emerged as the most abundant bacterial genus across the majority of samples. Compared with earlier Veggie system growouts conducted on the ISS between 2017 and 2018, the XROOTS crops carried a notably higher number of unique bacterial genera, 65 in leaf tissue and 87 in root tissue, compared with just 5 and 26 genera shared with those earlier missions, a difference the researchers linked partly to the XROOTS seeds not having been surface-sanitised before launch.

Food safety and what it means for future space missions

Among the fungi identified, researchers flagged two potential plant pathogens; Fusarium, an opportunistic fungus already known to affect ISS-grown crops, and Blumeria graminis, a fungus causing powdery mildew that had not been previously detected on the station and was found on wheat, tomato and pea plants grown together during the same growout. Despite these findings, no visible plant disease was observed, and researchers noted the presence of naturally occurring microbes, such as Pseudomonas and Trichoderma, known to compete against and suppress pathogens like Fusarium. The authors concluded that XROOTS performed well in microgravity and that understanding these plant-microbe relationships will be key to enabling reliable, Earth-independent food production on future lunar and Mars missions.

Representative Image (AI-generated)

What started as piles of concrete blocks on the seafloor off Prince Edward Island soon became a magnet for marine life. Researchers began installing the artificial oyster reefs in 2021 to test whether they could provide some of the ecological functions lost from areas where eelgrass no longer grew. Within two years, the structures had been colonised by 45 taxa, while biomass was about 45 times higher on two-year-old reefs than on newly installed ones. The findings, published in Ecosphere, show how a simple structure can provide a new foothold for marine life in a fragmented coastal habitat.

Turning bare seabed into new habitat

The work took place on the eastern end of Lennox Island, Prince Edward Island, where eelgrass (Zostera marina) meadows are broken up by patches of bare sediment. Instead of trying to plant eelgrass directly into those empty areas, researchers tested another idea. They built small artificial reefs from ordinary concrete blocks and placed them in the bare patches.The first 18 reefs went into the water in July 2021. Another 16 were added in 2022, followed by eight more in 2023. Each reef was made from eight to 10 concrete blocks arranged into a mound, creating several levels and surfaces above the seabed. The blocks gave oysters and other organisms something that bare sediment could not: a hard surface to settle on and grow. That was important because oyster reefs are more than collections of oysters. As they develop, they can create three-dimensional habitat that other marine organisms can use for shelter, feeding and attachment.

Life quickly began to gather

The structures did not remain bare for long. Researchers recorded 45 taxa across 11 phyla on the artificial reefs. They included plants, invertebrates and fish, with 29 of the taxa identified to species level. Oyster spat, or newly settled oysters, were among the first organisms to establish themselves. As the reefs aged, the community became more developed. The difference in biomass was particularly striking. Reefs that were less than a year old had an average biomass of about 35 grams. That increased to roughly 318 grams on one-year-old reefs.By the time the reefs were two years old, average biomass had reached about 1,577 grams. That was around five times the biomass recorded on one-year-old reefs and roughly 45 times the amount found on the newly installed structures. Much of that increase came from oysters growing on the reefs. The number of different taxa also changed as the structures matured. One-year-old reefs had an average of about 19 taxa, compared with roughly seven on the newest reefs.

Fish began using the reefs too

The structures were not simply places for oysters and other organisms to attach themselves. Researchers also observed fish using the older reefs for feeding and shelter. Fish diversity and evenness generally increased with reef age, although the fish observations were analysed descriptively because sample sizes were limited. Measurements also showed differences in several water-quality conditions around the reefs compared with nearby bare areas. Compared with nearby bare areas, the reef sites had lower temperatures and turbidity, higher dissolved oxygen and lower pH in the measurements recorded by the researchers. In other words, the reefs were beginning to affect their surroundings as well as provide a physical surface for marine life. That matters because one of the problems with fragmented coastal habitats is that losing a habitat-forming species can affect many other organisms that depend on it. Creating another type of structure may help fill at least some of that gap.

The reefs are not a replacement for eelgrass

The researchers do not suggest that concrete oyster reefs can simply replace eelgrass meadows. The project explored whether artificial reefs could provide some of the ecological functions of eelgrass habitat in areas where eelgrass was already absent. That distinction is important. Restoring eelgrass can be difficult when the environmental conditions responsible for its decline have not changed. Simply planting more eelgrass may not solve the underlying problem.An oyster reef offers a different approach. Rather than recreating the lost habitat exactly, it introduces another type of habitat that can support marine life under the existing conditions. The researchers describe this as ecological facilitation, with different habitat-forming species potentially providing complementary benefits.

Connecting restoration with the local community

The project was carried out in collaboration with the Lennox Island First Nation. The researchers note that oyster beds have historical ecological, cultural and food-security importance in the area and that many have since disappeared.The artificial reefs therefore offered a way to create new habitat while also supporting the return of oysters and other organisms. The researchers recorded species including lobster and forage fish using the developing structures. The approach is relatively simple, too. Concrete blocks are inexpensive, readily available and can be placed using a small boat, making the method potentially useful for smaller restoration projects.

What happens next

The results are encouraging, but the researchers point out that the reefs will need to be watched for longer to understand how their communities develop and how they interact with nearby eelgrass. A two-year-old reef is still relatively young, and the ecological effects could change as oysters continue to grow and more organisms arrive. Still, the experiment offers an interesting lesson in habitat restoration. Sometimes restoring a damaged ecosystem may not mean trying to recreate exactly what was there before. In fragmented coastal areas, creating new structures that give marine life somewhere to settle, feed and shelter could provide another way to rebuild some of the functions that have been lost.On Prince Edward Island, a collection of concrete blocks has already become a small but growing marine community, showing how quickly life can make use of a new piece of habitat.

Among the species benefiting from the restoration are yellow-eye mullet.

A major effort to remove invasive rice grass from Tasmania’s Duck Bay is showing major signs of recovery, with native vegetation returning and the number of fish species rising from five to 11. The changes came within just two to three years of the weed being removed from parts of the wetland.The restoration work is being carried out by Circular Head Landcare, which has spent almost 15 years trying to eradicate rice grass from Tasmania’s largest coastal wetlands, according to ABC news. The group, with support from farmers, has reduced the weed from about 50 hectares to just five hectares.Scientists from Univrersity of Tasmania studying the wetland also found that fish were not only returning but were using the restored saltmarsh areas for feeding. Among the species benefiting are yellow-eye mullet, which are caught both commercially and recreationally, and hardyheads, a small bait fish eaten by larger species.The restoration has required a large effort on land and in the water. Rice grass has been treated with the herbicide Fusilade Forte using quadbikes, vehicles with long hoses and, more recently, drones. Volunteers also search the coastline for seedlings that may have been missed or have grown again.

How rice grass spread across wetland

Rice grass was first planted in the 1940s to beautify Smithton’s Duck River. Over the years, it spread across mudflats and saltmarsh along a 120-kilometre stretch from Woolnorth to Stanley.The weed can form dense growth that takes over areas used by native plants and animals. Sue Jennings, a volunteer with Circular Head Landcare, says the grass became increasingly dense when left untreated.“All of these little sheltered bays were full of rice grass, which is a bright green, wavy grass up to your knee. It just gets thicker and thicker,” Jennings said.Duck Bay is part of Tasmania’s largest coastal wetland system, which includes sheltered bays, estuaries and tidal islands. The area is also important for shorebirds, with thousands visiting Tasmania’s far north-west during summer.Some of these birds travel long distances to reach the wetland. They include the far eastern curlew, ruddy turnstone and red-necked stint. The small red-necked stint weighs only about 30 to 35 grams.Shorebird ecologist Eric Woehler says red-necked stints can travel enormous distances during their lives. “Over 20 years, red-necked stints would fly half a million kilometres, which is farther than the distance between the earth and the moon,” Woehler said.The wetland also supports fish including gobies, sardines, flounder, galaxiids, garfish, leatherjackets and Australian salmon.

Rice grass was treated with herbicide using quadbikes, vehicles with long hoses and drones. (Photo: ABC)

Native saltmarsh plants return

Removing rice grass has allowed native saltmarsh vegetation to recover. Jennings says the herbicide being used kills pasture grass and rice grass but does not kill the saltmarsh plants.“It kills pasture grass and it kills rice grass, but it doesn’t kill the salt marsh plants. So as we get rid of the rice grass, the salt marsh plants start to recover on their own,” she says.The restoration is also important for nearby oyster farms. During mass herbicide spraying, harvesting is stopped for an additional seven days as a safety measure.According to Tasmanian Oyster Company chair Jon Poke, the pause can mean a significant financial loss for the business. The company can harvest up to 18,000 to 20,000 dozen oysters a week, meaning the two-week suspension could represent a lost opportunity of nearly half a million dollars in sales.However, Poke says protecting the wetland was important for the long-term survival of the farms. “We looked at what had happened in other estuaries, and for my own business to survive, we needed to make sure that the environment was looked after. Eventually rice grass would have closed our farms down,” he says.

Fish return after rice grass removal

University of Tasmania scientists have been tracking changes in native saltmarsh vegetation and fish communities as the restoration continues. Wetland ecologist Vishnu Prahalad says the recovery had happened faster than expected in some areas. “After two years, three years, you wouldn’t even be able to say there was rice grass there, so all the native vegetation has come back,” Prahalad said.The number of fish species recorded in the restored areas increased from five to 11. Scientists also saw a major change in the number of fish caught during their surveys. In the first year, researchers struggled to find fish, catching only two across four nets. “The first year, I think we caught two fish; we struggled to look for them, and there they were, two fish across four nets, which is very unusual,” Prahalad says.The difference became much clearer after the rice grass was removed. Researchers found about 200 mullets in one net. “After the rice grass was removed, in one net we had about 200 mullets,” Prahalad says.Scientists then examined whether the fish were simply able to enter the area more easily or were actually using the restored habitat. They found that the fish were feeding there and eating the typical food found in a saltmarsh. “Nature bouncing back is a wonderful thing to see,” says Prahlad.Circular Head Landcare hopes to finish treating the remaining rice grass meadows within the next two years, depending on weather and funding. Once the eradication work is complete, the area will be monitored for another decade. The amount of herbicide used is also expected to reduce as the weed becomes less common and the focus shifts to finding any remaining plants.