As the International Space Station whizzed over Mexico and the United States — before floodwaters catastrophically rose in Central Texas — a NASA astronaut watched the storms from miles above.
Nichole Ayers set up her camera to record a time-lapse movie in the orbiting laboratory’s cupola on Thursday. Her goal was to photograph exotic weather phenomena from an alien’s-eye view.
With planning and patience, she snagged a masterful shot of a gigantic jet, a rare type of lightning that shoots up from the top of a thunderstorm into the edge of space.
You read that right: There are indeed reverse lightning bolts that actually shoot toward the heavens rather than down to Earth’s surface. These are just one kind of “transient luminous event,” of which scientists know little. In fact, they’re so unusual that Ayers initially misidentified the jet as another type of TLE called a sprite, which occurs in the upper atmosphere above thunderstorms.
“Just. Wow,” she wrote in a July 3 post on X. “We have a great view above the clouds, so scientists can use these types of pictures to better understand the formation, characteristics, and relationship of TLEs to thunderstorms.”
SEE ALSO:
Think this space station and moon photo is AI? Meet the photographer.
NASA astronaut Nichole Ayers provided a labeled view of the transient luminous event she captured near the U.S.-Mexico border on July 3, 2025. Credit: NASA / Nichole Ayers
These so-called TLEs take many forms. They can disrupt communication systems and create flight risks for planes and spacecraft. Scientists want to better understand them to improve weather predictions.
Mashable Light Speed
But because they happen much higher than normal lightning and storm clouds, they’re hard to study. The European Space Agency has installed a monitor on the outside of the space station, which flies about 250 miles above Earth, to collect data on these events. The information is helping researchers unspool the mystery of all the ways thunderstorms can affect Earth’s atmosphere.
“The region of space above the thunderstorms is almost like an electrical zoo,” said Burcu Kosar, a space physicist, in a NASA video. “We have this collection of electrical activity. We have blue jets, gigantic jets, trolls, halos. It’s almost like an electric fairy tale.”
Kosar has spearheaded a new citizen science project that combines scientific data with the photography of storm chasers who have a knack for capturing TLEs. Called Spritacular, it’s the first crowdsourced database of these phenomena that is readily accessible to researchers.
What scientists do know about gigantic jets — and, yes, “gigantic” is part of their name, not an extra descriptor thrown in by this reporter — is that they seem to start like regular lightning inside a storm. Most of them have been spotted coming from tall, powerful storms over warm oceans. These storms often have a protruding top, where part of the cloud reaches higher than the atmosphere.
The gigantic jets may form when a strong and brief burst of rising air, called a convective pulse, happens inside the storm. The burst stirs things up near the top of the cloud, intensifying the storm. It also creates a layer of electric charge at the top.
Scientists think when the electric charges are stacked inside the cloud in a certain pattern, they allow lightning to break free from the top of the cloud. The gigantic jets emerge as bright tree or carrot shapes of plasma, looking a little like something out ofH.G. Wells’ The War of the Worlds.
Don Pettit, a NASA astronaut and photographer who recently returned to the planet from the space station, praised Ayers for her shot.
“To record a photo like this takes skill to set up the camera,” he wrote on X, “but more than that, the knowledge of what lightning systems are likely to create [TLEs] and the willingness to take 2000-5000 images where only one will record” the event.
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Got a sore throat and the sniffles? The recent rise of rapid at-home tests has made it easier to find out if you have a serious illness like COVID-19 or just a touch of spring allergies.
But while quick and convenient, these at-home tests are less sensitive than those available at the doctor’s office, meaning that you may still test negative even if you are infected.
A solution may come in the form of a new, low-cost biosensing technology that could make rapid at-home tests up to 100 times more sensitive to viruses like COVID-19. The diagnostic could expand rapid screening to other life-threatening conditions like prostate cancer and sepsis, as well.
Created by researchers at the University of California, Berkeley, the test combines a natural evaporation process called the “coffee-ring effect” with plasmonics and AI to detect biomarkers of disease with remarkable precision in just minutes.
“This simple yet effective technique can offer highly accurate results in a fraction of the time compared to traditional diagnostic methods,” said Kamyar Behrouzi, who recently completed a PhD in micro-electromechanical systems and nanoengineering at UC Berkeley. “Our work paves the way for more affordable, accessible diagnostics, especially in low-resource settings.”
The technology was developed with the support of seed funding from the CITRIS and Banatao Institute at the University of California and is described in a recent study published in the journal Nature Communications.
Combining coffee rings and nanoparticles
Look closely at any coffee or wine stain, and you might observe that the outline of the stain is much darker than the interior. This is due to a physical phenomenon called the coffee-ring effect: As a droplet of liquid evaporates, it generates a flow that pushes suspended particles towards the edge of the droplet. If the particles are pigmented, as they are in coffee and wine, the resulting stain will be darker around the rim than in the middle.
In 2020, Behrouzi was developing a biosensor for detecting COVID-19 when he noticed that droplets of his experimental solution were leaving ring-shaped stains as they dried. He realized that this coffee-ring effect could be used to easily concentrate particles of the COVID-19 virus, potentially making them easier to detect.
“We figured out that we could use this coffee-ring effect to build something even better than what we initially set out to create,” Behrouzi said.
The rapid test technology uses tiny particles called plasmonic nanoparticles that interact with light in unique ways. To conduct the test, a user first adds a droplet of liquid containing disease-relevant proteins — such as from a cheek or nasal swab — to a membrane. As the droplet dries, it concentrates any disease biomarkers at the coffee ring. The user then adds a second droplet containing plasmonic nanoparticles that have been engineered to stick to the disease biomarkers. If the biomarkers are present, the nanoparticles will aggregate in certain patterns that change how light interacts with the membrane. This change can be detected by eye or using an AI-powered smartphone app.
The technology gives results in less than 12 minutes and is 100 times more sensitive at detecting COVID-19 than equivalent tests.
“One of the key proteins that we are able to detect with this method is a biomarker of sepsis, a life-threatening inflammatory response to a bacterial infection that can develop rapidly in people over 50,” said study senior author Liwei Lin, a Distinguished Professor of Mechanical Engineering at UC Berkeley. “Every hour is critical, but culturing bacteria to determine the source of the infection can take a few days. Our technique could help doctors detect sepsis in 10 to 15 minutes.”
The researchers have created a prototype of a home testing kit, similar to at-home COVID testing kits, that includes 3D-printed components to help guide the placement of the sample and plasmonic droplets.
“During the COVID-19 pandemic, we relied on at-home tests to know if we were infected or not,” Lin said. “I hope that our technology makes it easier and more accessible for people to regularly screen for conditions like prostate cancer without leaving the home.”
Reference: Behrouzi K, Khodabakhshi Fard Z, Chen CM, He P, Teng M, Lin L. Plasmonic coffee-ring biosensing for AI-assisted point-of-care diagnostics. Nat Commun. 2025;16(1):1-13. doi: 10.1038/s41467-025-59868-y
This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source. Our press release publishing policy can be accessed here.
RESEARCHERS at the University of Queensland in Australia have developed and tested a software package that designs pest control solutions without relying on synthetic pesticides or genetic modification.
The open-source software package, dsRNAmax, harnesses an existing crop protection method known as RNA interference to target and kill pests and pathogens. Typically, the process involves applying double-stranded RNA (dsRNA) to plants, which interferes with the genes of unwanted organisms such as insects, viruses, fungi, and parasites.
The researchers believe their software is an important step forward in the goal of designing customisable pest killers that can each target a wide variety of pest species without impacting specified “beneficial organisms” – species of insects and microorganisms that aid crop growing.
The research, published in May in NAR Genomics and Bioinformatics, was led by PhD student Stephen Fletcher and Chris Brosnan, a research fellow at the Queensland Alliance for Agriculture and Food Innovation. Fletcher, who led the software development, said their motivation was to create software capable of designing a single dsRNA structure that can be used on “almost anything” while simultaneously having no impact on specified beneficial organisms.
The researchers lab-tested the software by using it to design a single dsRNA structure capable of targeting four species of root-knot nematodes – worm-like parasites measuring around 0.5 mm long. The design included specifications to have no impact on a C. Elegans nematode, known for its susceptibility to RNA interference, to demonstrate the software’s ability of excluding off-target species. Brosnan, who led the lab testing, said the results demonstrated the software’s effectiveness.
Use of dsRNA structures to kill pests and pathogens is seen as a more sustainable alternative to synthetic pesticides. A UN study in 2022 found that pests and pathogens cause annual production losses of around 40%, amounting to US$220bn, but typical methods of protecting crops often involve synthetic pesticides that can be environmentally harmful. Other methods based on the genetic modification of crops, meanwhile, can lead to “regulatory and public acceptance challenges”, the Queensland team says.
The researchers say that software packages similar to dsRNAmax have existed for “decades”, but most attempts have failed to design a single dsRNA structure that can target a wide variety of species while not impacting beneficial organisms. They now plan to optimise the software. “We’ll be using machine learning to improve the design to make our dsRNA 5–10% more effective, which would make a huge difference in a production system,” said Fletcher. “It also means we could use less dsRNA, which will bring down the cost.”
Cosmologists from the University of Portsmouth are part of an international team which wants to unlock the secrets of the ‘Cosmic Dawn’, by sending a miniature spacecraft to listen out for an “ancient whisper” on the far side of the Moon.
The proposed mission will study the very early universe, right after the Big Bang, when it was still quite dark and empty before the first stars and galaxies appeared.
But to probe the cosmic ‘Dark Ages’, silence is essential. And Earth is a very ‘noisy’ place for radio signals, with interference from our atmosphere and all our electronics.
“It’s like trying to hear that whisper while a loud concert is playing next door,” said Dr Eloy de Lera Acedo, who is presenting the proposal today at the Royal Astronomical Society’s National Astronomy Meeting 2025 in Durham .
“This makes it really hard to pick up those faint signals from billions of years ago. To detect a special radio signal that comes from hydrogen – the first, most basic and most abundant chemical element – in the early universe, we need it to be quiet.
“That’s why we’re proposing to send a small satellite to orbit the Moon and detect a signal which could hold clues about how everything began and how structures like galaxies eventually formed.”
The UK-led CosmoCube mission would observe from the far side of the Moon, which acts like a giant shield, blocking out all the radio noise from Earth.
This would create a clear, quiet spot to “listen” for an “ancient whisper” and learn more about the universe’s Dark Ages and Cosmic Dawn – periods that are currently largely unexplored.
“By doing this, CosmoCube aims to help us better understand how our universe transformed from a simple, dark state to the complex, light-filled cosmos we see today, with all its stars and galaxies,” said de Lera Acedo, head of Cavendish Radio Astronomy and Cosmology at the University of Cambridge.
“Crucially, it will also help scientists investigate the mysterious dark matter and its role in shaping these cosmic structures.”
CosmoCube will feature a precision-calibrated, low-power radio radiometer operating from a low-cost satellite platform in lunar orbit. It would operate at low frequencies (10-100 MHz), engineered to detect extremely faint signals amidst a sea of noise.
The mission could help shed light on the Hubble tension, a discrepancy between various measurements of the expansion rate of the Universe. It may also provide insights into the physics of the early Universe, and how normal and dark matter interact.
It may also provide insights into dark matter-baryon interactions (potential, non-gravitational interactions between dark matter particles and ordinary matter) and the physics of the early universe.
This so-called ‘Dark Ages’ period is one of the last unexplored frontiers in observational cosmology. The pre-stellar epoch offers a pristine view into the formation of structure, the properties of dark matter, and early cosmic evolution.
A blood Moon rising, mesmerising aurora displays, distant galaxies and the tangled threads of deep-sky cosmic clouds.
The Royal Observatory Greenwich have announced the shortlisted images from the ZWO Astronomy Photographer of the Year 2025 competition.
Winner – Our Sun and Overall Winner. Distorted Shadows of the Moon’s Surface Created by an Annular Eclipse, by Ryan Imperio, Odessa, Texas, USA
Now in its 17th year, the astrophotography competition is the biggest in the world, and in 2025 received over 5,500 entries from photographers in 69 countries across the globe.
The shortlisted images from Astronomy Photographer of the Year 17 include a moonrise over the Dolomites, red-hued Northern Lights at Mono Lake, California, and Comet C/2023 A3 (Tsuchinshan-ATLAS).
Formerly known as the Annie Maunder Prize for Image Innovation, the newly-titled Annie Maunder Open Category gives entrants the chance to experiment with different approaches to astrophotography by using astronomical data in a creative, conceptual way.
Neon Sun by Peter Ward, uses images taken by NASA’s Solar Dynamics Observatory, remapped with a vibrant palette.
Data on the Sun’s corona – its outer atmosphere – is turned inside out to surround the Sun, creating the illusion of it being enclosed in a neon tube.
The winners of the 2025 Astronomy Photographer of the Year competition will be announced during an online ceremony in September 2025.
Thereafter, the winning images will be showcased alongside a selection of some of the best entries this year, in an exhibition at the National Maritime Museum in London, UK.
The exhibition opens 12 September 2025.
For more information, follow Royal Museums Greenwich on X, Instagram and Facebook, or by using the hashtag #APY17.
In the meantime, let’s take a look at all of the Astronomy Photographer of the Year shortlist images for 2025.
A team of international researchers led by Tomas Stolker in the Netherlands has imaged a young gas giant exoplanet near a 12-million-year-old star. The planet is orbiting a star at which planet formation has finished, while the same-aged companion star still has a planet-forming disk. The researchers published their findings in the journal Astronomy & Astrophysics.
The double star system HD 135344 AB is located approximately 440 light-years away in the constellation Lupus. It consists of two young stars, A and B, that orbit each other at great distances.
Tomas Stolker of Leiden University in the Netherlands studied star B during his doctoral research from 2013 to 2017 because of its interesting planet-forming disk. ‘Star A had never been investigated because it does not contain a disk. My colleagues and I were curious if it had already formed a planet,’ says Stolker. ‘And so, after four years of careful measurements and some luck, the answer is yes.’
The newly discovered exoplanet HD 135344 Ab is a young gas giant, no more than 12 million years old. It has a mass about 10 times that of Jupiter. The planet’s distance from its star is comparable to Uranus’ orbit around the Sun.
The researchers point out that star A has already finished forming planets, while star B still has a protoplanetary disk. This demonstrates that planet formation around binary stars can occur on different timelines.
Four years of tracking
The researchers used the SPHERE instrument on the Very Large Telescope (VLT) to capture the faint light of the potential planet. They found the planet quickly, but for a long time, it was unclear whether it was a planet or a background star. To rule out the possibility of a background star, the researchers tracked the planet also with the GRAVITY instrument. This instrument combines light from the VLT’s four large telescopes, enabling it to map the planet’s location with great precision. Over four years, the researchers observed the star and planet seven times and saw them move together. In other words, there is no background star.
‘We’ve been lucky, though,’ says Stolker. ‘The angle between the planet and the star is now so small that SPHERE can barely detect the planet.’
The newly discovered exoplanet HD 135344 Ab can be seen as a yellow dot on the right side of the image. It was measured in 2019 (2x), 2021, and 2022. The empty purple circle with the star in the middle indicates the location of the corresponding star. This star was filtered out, first by a coronograph and further by digital post-processing. (c) Stolker et al.
New population?
In the future, researchers will continue to monitor the planet using the GRAVITY instrument. They also hope to point the ELT, which is currently under construction, to the planet. This will allow them to determine the composition of the atmosphere and learn more about the planet’s evolution. Additionally, they plan to search for gas giants near other young stars at distances similar to the orbit of the newly discovered exoplanet. The researchers think that HD 135344 Ab might be part of a population of exoplanets that have so far been difficult to detect.
Scientific paper
Direct imaging discovery of a young giant planet orbiting on solar system scales. By: T. Stolker, et al. In: Astronomy & Astrophysics, 9 July 2025. [original (open access, available after 9 July | preprint (pdf)]
Buried in the 870 pages of the One Big Beautiful Bill, there is a concession to Republican representatives from states closely linked to the manned space exploration program, which was facing massive layoffs and unprecedented cuts. Another victim of this concession is the tycoon Elon Musk, as Trump’s decision takes away lucrative contracts for his space rockets. Europe, on the other hand, is breathing a sigh of relief.
The law recently approved by Congress revives Gateway, the future space station that will orbit the Moon. The federal government will spend $2.6 billion on this manned base, the construction of which also involves the European Space Agency (ESA) along with Canada, Japan and the United Arab Emirates. The measure is a sharp U-turn from what Trump was proposing just over a month ago: to completely cancel the project and leave all its international partners in the lurch.
Something similar is happening with the Space Launch System (SLS), with which the U.S. government aims to send the first woman astronaut to the Moon in 2027. The BBB will ultimately include more than $4 billion to fund at least two additional flights with this launch vehicle, beyond those already planned for the Artemis 2 and 3 missions. Trump’s original idea was to eliminate it after these two flights and perhaps resort to the Starship being developed by SpaceX, Elon Musk’s company. But this latter system is far from ready to carry astronauts, and has already accumulated several spectacular explosions, the last of them before even attempting takeoff.
Furthermore, the clash between the U.S. president and the tycoon is increasingly evident. Musk has announced that he will create a political party in the United States to steal voters from Trump. The president has called it “ridiculous” and described Musk as a “train wreck.” The president has also threatened to withdraw important public contracts held by Musk’s companies such as SpaceX and the electric car manufacturer Tesla.
Trump had bought into Musk’s idea of sending astronauts to Mars as soon as possible, a very different option than the one the U.S. space agency had been planning for years. The new funding returns to the original vision of first sending astronauts to the Moon, building an orbital station there, and recovering the Orion capsules for the Artemis 4 and 5 missions, formally planned for 2028 and 2030, which will also be transported by SLS rockets, which both Trump and Musk had criticized as too expensive and obsolete.
One of the big winners from these measures is Europe, which had watched with horror as many of the joint programs it had invested the most money and effort in were threatened with cancellation. The European Space Agency (ESA), for example, is responsible for building a habitation module for the future Gateway lunar station, as well as a storage module, a fuel depot, and the only place in the entire facility with windows, through which astronauts can look out to contemplate the lunar surface and outer space. Europe will also benefit from the extended life of the Orion spacecraft, for which it manufactures the service module that provides power and propulsion.
Trump’s mega-law also includes a significant injection of $1.2 billion in funding for the International Space Station (ISS) until 2029, before its retirement the following year. This is also key for Europe, as it could ensure that European astronauts, including the Spaniard Pablo Álvarez, can travel to space before 2030.
An uninhabited space station
“If the United States pulled out of Gateway, the project would be dead,” acknowledges an executive from one of Europe’s leading aerospace companies. “Europe could have completed the station on its own, but for the time being, it doesn’t have access to space for its astronauts; it relies on Russian Soyuz spacecraft or commercial U.S. spacecraft, so what we were facing was having an uninhabited space station on the Moon,” he explains.
The main reason the United States has decided to increase funding for the ISS is geopolitical, these sources point out. China has an Earth orbital station, and it would be a complete defeat if the “Western world” didn’t have a similar facility, the ISS, or a larger one, the Gateway, when it’s ready later this decade.
On the other hand, nobody can save NASA’s robotic exploration missions and other scientific programs, which are facing unprecedented cuts. Trump’s budget only includes increases for manned exploration programs, but in return, he will cut the science budget in half. This will force the cancellation of 41 projects, including 19 active space missions.
The person responsible for this major change of tack is Texas Republican Senator Ted Cruz, who chairs the Senate Committee on Commerce, Science, and Transportation and who is believed to have pushed for the new funds to prevent the hundreds of layoffs that Trump’s policies would have caused in his state.
“It’s been a lightning-fast change of direction, perhaps the fastest I’ve ever seen in this field,” Casey Dreier, head of space policy at the Planetary Society of the United States, told this newspaper. However, the expert at this non-profit organization founded by Carl Sagan in 1980 believes the scope of the new law is “disappointing” because it doesn’t include any relief from the planned cuts to science, education, and other areas. This is also explained by politics. “By an accident of history, NASA’s human space exploration centers are all in Republican-governed states. No Democratic congressman was going to support this law, so only the highest priorities of the Republican Party were considered,” Dreier explains. The specialist believes this situation opens the possibility that NASA’s science sector will fare somewhat better in the congressional debate on the budget, which must conclude before October 1. Since the BBB has set amounts for human exploration, perhaps this will leave some more money for other NASA projects and other federal agencies, which are facing brutal cuts.
The outlook for the coming months remains highly uncertain. NASA has been in a state of disarray since Donald Trump unexpectedly decided to remove Jared Isaacman, a billionaire he himself had appointed to head the agency. Isaacman is very close to Musk and had to juggle in the Senate to defend the country’s desire to reach the Moon before China, but also to prioritize missions to Mars, as Musk wanted. Ultimately, the rift between the president and the magnate left him without a position, and with no successor in sight. “I also found it inappropriate that a very close friend of Elon’s, who was involved in the Space Business, should run NASA, given that NASA is such a significant part of Elon’s corporate life,” Trump wrote on his Truth Social network.
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Quantum sensors have become important tools in low-energy particle physics. Michael Doser explores opportunities to exploit their unparalleled precision at higher energies.
Quantum sensitivity The Axion Dark Matter Experiment (ADMX) searches for ultra-light bosonic dark matter in the 1 to 40 μeV mass range by detecting possible conversions of axions into microwave photons inside a high–quality-factor superconducting cavity. Quantum-limited amplifiers, cooled to millikelvin temperatures, push the detector’s sensitivity toward the limits set by quantum measurement noise. Credit: T Luong
Atomic energy levels. Spin orientations in a magnetic field. Resonant modes in cryogenic, high-quality-factor radio-frequency cavities. The transition from superconducting to normal conducting, triggered by the absorption of a single infrared photon. These are all simple yet exquisitely sensitive quantum systems with discrete energy levels. Each can serve as the foundation for a quantum sensor – instruments that detect single photons, measure individual spins or record otherwise imperceptible energy shifts.
Over the past two decades, quantum sensors have taken on leading roles in the search for ultra-light dark matter and in precision tests of fundamental symmetries. Examples include the use of atomic clocks to probe whether Earth is sweeping through oscillating or topologically structured dark-matter fields, and cryogenic detectors to search for electric dipole moments – subtle signatures that could reveal new sources of CP violation. These areas have seen rapid progress, as challenges related to detector size, noise, sensitivity and complexity have been steadily overcome, opening new phase space in which to search for physics beyond the Standard Model. Could high-energy particle physics benefit next?
Low-energy particle physics
Most of the current applications of quantum sensors are at low energies, where their intrinsic sensitivity and characteristic energy scales align naturally with the phenomena being probed. For example, within the Project 8 experiment at the University of Washington, superconducting sensors are being developed to tackle a longstanding challenge: to distinguish the tiny mass of the neutrino from zero (see “Quantum-noise limited” image). Inward-looking phased arrays of quantum-noise-limited microwave receivers allow spectroscopy of cyclotron radiation from beta-decay electrons as they spiral in a magnetic field. The shape of the endpoint of the spectrum is sensitive to the mass of the neutrino and such sensors have the potential to be sensitive to neutrino masses as low as 40 meV.
Quantum-noise limited In a bid to measure the mass of the neutrino, the Project 8 collaboration uses superconducting sensors to study the endpoint of beta-decay spectra. Credit: A Lindman/Project 8 Collaboration
Beyond the Standard Model, superconducting sensors play a central role in the search for dark matter. At the lowest mass scales (peV to meV), experiments search for ultralight bosonic dark-matter candidates such as axions and axion-like particles (ALPs) through excitations of the vacuum field inside high–quality–factor microwave and millimetre-wave cavities (see “Quantum sensitivity” image). In the meV range, light-shining-through-wall experiments aim to reveal brief oscillations into weakly coupled hidden-sector particles such as dark photons or ALPs, and may employ quantum sensors for detecting reappearing photons, depending on the detection strategy. In the MeV to sub-GeV mass range, superconducting sensors are used to detect individual photons and phonons in cryogenic scintillators, enabling sensitivity to dark-matter interactions via electron recoils. At higher masses, reaching into the GeV regime, superfluid helium detectors target nuclear recoils from heavier dark matter particles such as WIMPs.
These technologies also find broad application beyond fundamental physics. For example, in superconducting and other cryogenic sensors, the ability to detect single quanta with high efficiency and ultra-low noise is essential. The same capabilities are the technological foundation of quantum communication.
Raising the temperature
While many superconducting quantum sensors require ultra-low temperatures of a few mK, some spin-based quantum sensors can function at or near room temperature. Spin-based sensors, such as nitrogen-vacancy (NV) centres in diamonds and polarised rubidium atoms, are excellent examples.
NV centres are defects in the diamond lattice where a missing carbon atom – the vacancy – is adjacent to a lattice site where a carbon atom has been replaced by a nitrogen atom. The electronic spin states in NV centres have unique energy levels that can be probed by laser excitation and detection of spin-dependent fluorescence.
Researchers are increasingly exploring how quantum-control techniques can be integrated into high-energy-physics detectors
Rubidium is promising for spin-based sensors because it has unpaired electrons. In the presence of an external magnetic field, its atomic energy levels are split by the Zeeman effect. When optically pumped with laser light, spin-polarised “dark” sublevels – those not excited by the light – become increasingly populated. These aligned spins precess in magnetic fields, forming the basis of atomic magnetometers and other quantum sensors.
Being exquisite magnetometers, both devices make promising detectors for ultralight bosonic dark-matter candidates such as axions. Fermion spins may interact with spatial or temporal gradients of the axion field, leading to tiny oscillating energy shifts. The coupling of axions to gluons could also show up as an oscillating nuclear electric dipole moment. These interactions could manifest as oscillating energy-level shifts in NV centres, or as time-varying NMR-like spin precession signals in the atomic magnetometers.
Large-scale detectors
The situation is completely different in high-energy physics detectors, which require numerous interactions between a particle and a detector. Charged particles cause many ionisation events, and when a neutral particle interacts it produces charged particles that result in similarly numerous ionisations. Even if quantum control were possible within individual units of a massive detector, the number of individual quantum sub-processes to be monitored would exceed the possibilities of any realistic device.
Increasingly, however, researchers are exploring how quantum-control techniques – such as manipulating individual atoms or spins using lasers or microwaves – can be integrated into high-energy-physics detectors. These methods could enhance detector sensitivity, tune detector response or enable entirely new ways of measuring particle properties. While these quantum-enhanced or hybrid detection approaches are still in their early stages, they hold significant promise.
Quantum dots
Quantum dots are nanoscale semiconductor crystals – typically a few nanometres in diameter – that confine charge carriers (electrons and holes) in all three spatial dimensions. This quantum confinement leads to discrete, atom-like energy levels and results in optical and electronic properties that are highly tunable with size, shape and composition. Originally studied for their potential in optoelectronics and biomedical imaging, quantum dots have more recently attracted interest in high-energy physics due to their fast scintillation response, narrow-band emission and tunability. Their emission wavelength can be precisely controlled through nanostructuring, making them promising candidates for engineered detectors with tailored response characteristics.
Chromatic calorimetry Left: the absorption (dashed lines) and emission (solid lines) spectra of quantum dots depend on their composition, geometry, surface treatment and size, with smaller dots (~2 nm) emitting blue light and larger dots (~4 nm) emitting red light. Right: a novel calorimeter could be designed by stacking materials embedded with different sized, narrow-band quantum dots adjacent to a spectrally sensitive photon detector. Credit: Adapted from Y Haddad et al. 2025 arXiv:2501.12738
While their radiation hardness is still under debate and needs to be resolved, engineering their composition, geometry, surface and size can yield very narrow-band (20 nm) emitters across the optical spectrum and into the infrared. Quantum dots such as these could enable the design of a “chromatic calorimeter”: a stack of quantum-dot layers, each tuned to emit at a distinct wavelength; for example red in the first layer, orange in the second and progressing through the visible spectrum to violet. Each layer would absorb higher energy photons quite broadly but emit light in a narrow spectral band. The intensity of each colour would then correspond to the energy absorbed in that layer, while the emission wavelength would encode the position of energy deposition, revealing the shower shape (see “Chromatic calorimetry” figure). Because each layer is optically distinct, hermetic isolation would be unnecessary, reducing the overall material budget.
Rather than improving the energy resolution of existing calorimeters, quantum dots could provide additional information on the shape and development of particle showers if embedded in existing scintillators. Initial simulations and beam tests by CERN’s Quantum Technology Initiative (QTI) support the hypothesis that the spectral intensity of quantum-dot emission can carry information about the energy and species of incident particles. Ongoing work aims to explore their capabilities and limitations.
Beyond calorimetry, quantum dots could be formed within solid semiconductor matrices, such as gallium arsenide, to form a novel class of “photonic trackers”. Scintillation light from electronically tunable quantum dots could be collected by photodetectors integrated directly on top of the same thin semiconductor structure, such as in the DoTPiX concept. Thanks to a highly compact, radiation-tolerant scintillating pixel tracking system with intrinsic signal amplification and minimal material budget, photonic trackers could provide a scintillation-light-based alternative to traditional charge-based particle trackers.
Living on the edge
Low temperatures also offer opportunities at scale – and cryogenic operation is a well-established technique in both high-energy and astroparticle physics, with liquid argon (boiling point 87 K) widely used in time projection chambers and some calorimeters, and some dark-matter experiments using liquid helium (boiling point 4.2 K) to reach even lower temperatures. A range of solid-state detectors, including superconducting sensors, operate effectively at these temperatures and below, and offer significant advantages in sensitivity and energy resolution.
Single-photon phase transitions Left: a sample image taken at 370 nm by a large-scale superconducting-nanowire single-photon detector pixel array with multi-bus readout. Raw time-delay (red) and binned (black and white) data is shown across 400,000 (800 × 500) pixels. Right: a false-colour scanning electron micrograph of a corner of the sensor shows bus connections alongside a simplified schematic (top right) and a zoom into a single 5 × 5 μm pixel (inset). The sensor operates by registering when individual photons induce nanowires to change state from superconducting to normal conducting. Credit: B G Oripov et al. 2023 arXiv:2306.09473
Magnetic microcalorimeters (MMCs) and transition-edge sensors (TESs) operate in the narrow temperature range where a superconducting material undergoes a rapid transition from zero resistance to finite values. When a particle deposits energy in an MMC or TES, it slightly raises the temperature, causing a measurable increase in resistance. Because the transition is extremely steep, even a tiny temperature change leads to a detectable resistance change, allowing precise calorimetry.
Functioning at millikelvin temperatures, TESs provide much higher energy resolution than solid-state detectors made from high-purity germanium crystals, which work by collecting electron–hole pairs created when ionising radiation interacts with the crystal lattice. TESs are increasingly used in high-resolution X-ray spectroscopy of pionic, muonic or antiprotonic atoms, and in photon detection for observational astronomy, despite the technical challenges associated with maintaining ultra-low operating temperatures.
By contrast, superconducting nanowire and microwire single-photon detectors (SNSPDs and SMSPDs) register only a change in state – from superconducting to normal conducting – allowing them to operate at higher temperatures than traditional low-temperature sensors. When made from high–critical-temperature (Tc) superconductors, operation at temperatures as high as 10 K is feasible, while maintaining excellent sensitivity to energy deposited by charged particles and ultrafast switching times on the order of a few picoseconds. Recent advances include the development of large-area devices with up to 400,000 micron-scale pixels (see “Single-photon phase transitions” figure), fabrication of high-Tc SNSPDs and successful beam tests of SMSPDs. These technologies are promising candidates for detecting milli-charged particles – hypothetical particles arising in “hidden sector” extensions of the Standard Model – or for high-rate beam monitoring at future colliders.
Rugged, reliable and reproducible
Quantum sensor-based experiments have vastly expanded the phase space that has been searched for new physics. This is just the beginning of the journey, as larger-scale efforts build on the initial gold rush and new quantum devices are developed, perfected and brought to bear on the many open questions of particle physics.
Partnering with neighbouring fields such as quantum computing, quantum communication and manufacturing is of paramount importance
To fully profit from their potential, a vigorous R&D programme is needed to scale up quantum sensors for future detectors. Ruggedness, reliability and reproducibility are key – as well as establishing “proof of principle” for the numerous imaginative concepts that have already been conceived. Challenges range from access to test infrastructures, to standardised test protocols for fair comparisons. In many cases, the largest challenge is to foster an open exchange of ideas given the numerous local developments that are happening worldwide. Finding a common language to discuss developments in different fields that at first glance may have little in common, builds on a willingness to listen, learn and exchange.
The European Committee for Future Accelerators (ECFA) detector R&D roadmap provides a welcome framework for addressing these challenges collaboratively through the Detector R&D (DRD) collaborations established in 2023 and now coordinated at CERN. Quantum sensors and emerging technologies are covered within the DRD5 collaboration, which ties together 112 institutes worldwide, many of them leaders in their particular field. Only a third stem from the traditional high-energy physics community.
These efforts build on the widespread expertise and enthusiastic efforts at numerous institutes and tie in with the quantum programmes being spearheaded at high-energy-physics research centres, among them CERN’s QTI. Partnering with neighbouring fields such as quantum computing, quantum communication and manufacturing is of paramount importance. The best approach may prove to be “targeted blue-sky research”: a willingness to explore completely novel concepts while keeping their ultimate usefulness for particle physics firmly in mind.
Further reading
C Peña et al. 2025 JINST20 P03001. G Hallais et al. 2023 Nucl. Instrum. Methods Phys. Res. A 1047 167906. B G Oripov et al. 2023 Nature622 730. L Gottardi and S Smith 2022 arXiv:2210.06617.
“Space ice” contains tiny crystals and is not, as previously assumed, a completely disordered material like liquid water, according to a new study by scientists at UCL (University College London) and the University of Cambridge.
Ice in space is different to the crystalline (highly ordered) form of ice on Earth. For decades, scientists have assumed it is amorphous (without a structure), with colder temperatures meaning it does not have enough energy to form crystals when it freezes.
In the new study, published in Physical Review B, researchers investigated the most common form of ice in the Universe, low-density amorphous ice, which exists as the bulk material in comets, on icy moons and in clouds of dust where stars and planets form.
They found that computer simulations of this ice best matched measurements from previous experiments if the ice was not fully amorphous but contained tiny crystals (about three nanometers wide, slightly wider than a single strand of DNA) embedded within its disordered structures.
In experimental work, they also re-crystallized (i.e. warmed up) real samples of amorphous ice that had formed in different ways. They found that the final crystal structure varied depending on how the amorphous ice had originated. If the ice had been fully amorphous (fully disordered), the researchers concluded, it would not retain any imprint of its earlier form.
Lead author Dr Michael B. Davies, who did the work as part of his PhD at UCL Physics & Astronomy and the University of Cambridge, said: “We now have a good idea of what the most common form of ice in the Universe looks like at an atomic level.
“This is important as ice is involved in many cosmological processes, for instance in how planets form, how galaxies evolve, and how matter moves around the Universe.”
The findings also have implications for one speculative theory about how life on Earth began. According to this theory, known as Panspermia, the building blocks of life were carried here on an ice comet, with low-density amorphous ice the space shuttle material in which ingredients such as simple amino acids were transported.
Dr Davies said: “Our findings suggest this ice would be a less good transport material for these origin of life molecules. That is because a partly crystalline structure has less space in which these ingredients could become embedded.
“The theory could still hold true, though, as there are amorphous regions in the ice where life’s building blocks could be trapped and stored.”
Co-author Professor Christoph Salzmann, of UCL Chemistry, said: “Ice on Earth is a cosmological curiosity due to our warm temperatures. You can see its ordered nature in the symmetry of a snowflake.
“Ice in the rest of the Universe has long been considered a snapshot of liquid water — that is, a disordered arrangement fixed in place. Our findings show this is not entirely true.
“Our results also raise questions about amorphous materials in general. These materials have important uses in much advanced technology. For instance, glass fibers that transport data long distances need to be amorphous, or disordered, for their function. If they do contain tiny crystals and we can remove them, this will improve their performance.”
For the study, the researchers used two computer models of water. They froze these virtual “boxes” of water molecules by cooling to -120 degrees Centigrade at different rates. The different rates of cooling led to varying proportions of crystalline and amorphous ice.
They found that ice that was up to 20% crystalline (and 80% amorphous) appeared to closely match the structure of low-density amorphous ice as found in X-ray diffraction studies (that is, where researchers fire X-rays at the ice and analyse how these rays are deflected).
Using another approach, they created large “boxes” with many small ice crystals closely squeezed together. The simulation then disordered the regions between the ice crystals reaching very similar structures compared to the first approach with 25% crystalline ice.
In additional experimental work, the research team created real samples of low-density amorphous ice in a range of ways, from depositing water vapor on to an extremely cold surface (how ice forms on dust grains in interstellar clouds) to warming up what is known as high-density amorphous ice (ice that has been crushed at extremely cold temperatures).
The team then gently heated these amorphous ices so they had the energy to form crystals. They noticed differences in the ices’ structure depending on their origin — specifically, there was variation in the proportion of molecules stacked in a six-fold (hexagonal) arrangement.
This was indirect evidence, they said, that low-density amorphous ice contained crystals. If it was fully disordered, they concluded, the ice would not retain any memory of its earlier forms.
The research team said their findings raised many additional questions about the nature of amorphous ices — for instance, whether the size of crystals varied depending on how the amorphous ice formed, and whether a truly amorphous ice was possible.
Amorphous ice was first discovered in its low-density form in the 1930s when scientists condensed water vapor on a metal surface cooled to -110 degrees Centigrade. Its high-density state was discovered in the 1980s when ordinary ice was compressed at nearly -200 degrees Centigrade.
The research team behind the latest paper, based both at UCL and the University of Cambridge, discovered medium-density amorphous ice in 2023. This ice was found to have the same density as liquid water (and would therefore neither sink nor float in water).
Co-author Professor Angelos Michaelides, from the University of Cambridge, said: “Water is the foundation of life but we still do not fully understand it. Amorphous ices may hold the key to explaining some of water’s many anomalies.”
Dr Davies said: “Ice is potentially a high-performance material in space. It could shield spacecraft from radiation or provide fuel in the form of hydrogen and oxygen. So we need to know about its various forms and properties.”
