Ice phase with orthorhombic symmetry revealed under high pressure.
H2O ice is of fundamental importance to all fields of the physical sciences. Existing in the most extreme environments of the universe, ice is found in comets traveling through the cold vacuum of space, and deep within the hot, dense interiors of giant planets. Despite being a simple molecule, ice possesses a complex pressure-temperature phase diagram, with 21 distinct solid phases reported to date.
At room temperature, the picture is far simpler, with only three known solid ices observed upon compression: ice VI, ice VII and ice X. It was predicted almost 30 years ago that beyond ice X there would be an eventual transformation from a crystal with cubic symmetry to one with orthorhombic symmetry, however it has remained elusive and thought beyond experimental capabilities.
Now a team from the Centre for Science of Extreme Conditions (CSEC), a multi-disciplinary group involving researchers from the School’s Institute for Condensed Matter and Complex Systems (ICMCS), reports on the discovery of this phase in Nature Materials. Named ice XXII, this phase exists only at pressures around 300 GPa (which is 3 million times atmospheric pressure) and was formed by squeezing water between the tips of two diamond anvils.
Through a combination of x-ray diffraction, spectroscopy and density functional theory calculations, the team demonstrates that the cubic ice X structure possessing symmetric oxygen-hydrogen bonds continuously distort before the bonds buckle, giving rise to ice XII.
Given the vast pressure stability regime predicted for ice XXII, current experimental limitations most likely render this the last phase of ice to be discovered at room temperature.
Dr Israel Osmond, first author of the study said:
Given that water barely scatters x-rays at all, this really is pushing high-pressure crystallography to its absolute limits. It’s a real testament to how far diamond anvil cell techniques have come.
Recalling the moment of the discovery, Dr Ross Howie, co-lead of the study, said:
We ran the sample by chance as we didn’t expect to observe anything – how wrong we were! Exciting discoveries like this don’t happen every day and it is great that so many early career researchers and students involved in the study got to be a part of it.
Dr Miriam Pena-Alvarez, co-lead of the study, said:
Most matter in the universe doesn't exist at the atmospheric conditions we are familiar with but exists under high pressure. This is what drives our lab, and this work in particular: recreating those planetary interiors in house, to provide insight on how one of the universe's most abundant molecule behaves under these extreme pressures.
The project also involved contributions from Professor Andreas Hermann, and the work was funded through the ERC Starting Grant of Dr Ross Howie and Future Leaders Fellowship of Dr Miriam Peña-Alvarez.
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Research team uncover quantum stabilized manganese superhydride at extreme pressures.
Over the past 10 years, the application of high-pressure physics has proved an effective synthesis route to produce hydrogen-rich materials that would otherwise be unattainable. Amongst them, so-called metal superhydrides: hydrogen-rich compounds containing five or more hydrogen atoms per metal atom, many of which exhibit fascinating properties such as high-temperature superconductivity. While superhydrides can form with a number of rare earth metal species, they are a rarity amongst the group IV-XII transition metals - in fact, only a single example, iron hydride (FeH5), has been reported to date.
In work published in Angewandte Chemie, a research team based in the School’s Institute for Condensed Matter and Complex Systems report the synthesis of the second known transition metal superhydride, MnH7, at pressures above 118 GPa - around 1.2 million atmospheres. Using a tiny sample just 10 micrometers in size (smaller than the width of a human hair), and held between the tips of two opposing diamonds, the team was able to measure various structural and spectroscopic properties. These measurements were accompanied by density functional theory calculations - a method used to obtain the binding energies of materials at an atomistic level. These calculations were useful for determining the number and location of hydrogen atoms within the sample.
Surprisingly, the crystal structure of MnH7 turned out to be completely different from the phase predicted by theory to be the most stable. This result can be explained by the rules of quantum mechanics. Even at absolute zero temperature, nuclei are not fixed. Instead, they remain spread in a range of positions and retain a specific energy, the so-called zero-point energy. This energy, the lowest possible energy state of the quantum nuclear system, depends on the crystal structure of the compound, and is more important for light elements, such as hydrogen.
In MnH7, the role of zero-point energy is so important that, once included in the calculations, the previously most stable structure (which features hydrogen molecules) was superseded by the experimentally determined structure (which has hydrogen atoms) as the most stable phase. This suggests that the new superhydride MnH7 forms because of the quantum nature of the proton within the hydrogen atoms’ nucleus.
The first author of this study is Postdoctoral Research Associate, Dr Mikhail Kuzovnikov. The experimental work was led by Dr Ross Howie and supported by ERC (European Research Council) Starting Grant 'MetElOne', whilst the theoretical work was led by Professor Andreas Hermann.
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The LUX-ZEPLIN (LZ) experiment reports a signal that cannot be explained by any known background.
A single particle interaction is the most intriguing signal reported so far by the LUX-ZEPLIN (LZ) dark matter experiment — though researchers say more data is needed before any claim can be made.
Dark matter is thought to make up around 85% of all the matter in the universe, yet it has never been directly detected. Now, a new analysis from the LZ experiment has identified a single particle interaction that researchers have struggled to explain using any known background process. The result falls short of the statistical threshold required to claim a discovery but is the most compelling hint of dark matter the experiment has reported to date.
LZ is an international collaboration of around 250 scientists and engineers. The detector, which uses 10 tonnes of ultrapure liquid xenon to search for weakly interacting massive particles (WIMPs), is managed by the U.S. Department of Energy's Lawrence Berkeley National Laboratory and operates nearly a mile underground at the Sanford Underground Research Facility (SURF) in South Dakota, USA.
Funded in the UK by the Science and Technology Facilities Council (STFC) for both construction and operations, ten UK teams play a central role in LZ, including researchers from the University of Edinburgh. The analysis behind this result was led by the LZ group at the University of Bristol and was presented at the 2026 TeV Particle Astrophysics conference in Japan. The paper is available on the LZ Dark Matter Experiment website and has been submitted to the journal Physical Review Letters.
Dr Sam Eriksen, a senior research associate at the University of Bristol and lead author of the study said:
This was a detailed study in a region we hadn’t explored within this dataset, and we spent months of additional effort to understand all the possible causes of background events. We understand our detector and the backgrounds so well that even a single outstanding event, like the one we found, is important. We expect dark matter events to be extremely rare, so only a handful could mark the first detection of WIMP dark matter.
If the event was caused by dark matter, it would point to a WIMP with a mass of at least 200 GeV/c² (gigaelectron volts), or more than 200 times the mass of a proton, interacting with ordinary matter in a way not covered by the simplest theoretical models. The result stands at 2.6 sigma significance, meaning there is roughly a 0.5% chance it could be explained by known backgrounds alone. This is well short of the 5-sigma threshold that physics requires before a result can be called a discovery.
LZ's results so far include the most sensitive dark-matter searches to date, the most significant observation of solar boron-8 neutrinos, and today's result, which could be an early hint of a dark-matter detection. Together, they reflect years of collaborative work across the international team and point to the value of continuing the search with a larger successor experiment.
The UK team is already working with international partners on the next phase: XLZD (XENON-LUX-ZEPLIN-DARWIN), a next-generation rare-event observatory for dark matter detection and neutrino physics, drawing on the double-phase liquid xenon technology pioneered in the UK. The project is currently supported by a UKRI Infrastructure Fund preliminary activity, and the UK is exploring the possibility of hosting the experiment at the Boulby Underground Laboratory.
Professor Alex Murphy, Personal Chair in Nuclear & Particle Astrophysics, at the University of Edinburgh, said:
One of the first to consider the possibility – and perform calculations – of unseen matter in the galaxy was Lord Kelvin, of Glasgow University, way back in 1904. So there’s a lot of history here in the UK. Rather than perhaps being an end to this journey, the interesting event we’ve seen might be a whole new start. It’s especially exciting to think that the Boulby Underground Laboratory could feature highly in whatever comes next.
University of Edinburgh researchers in this field also include academic Dr Sally Shaw, postdoctoral researchers Dr Alberto Uson and Dr Sam Woodford, and PhD students Ellie Bishop and Huan Zhang. They specialise in areas key to the dark matter search – neutron backgrounds and simulations, and more exotic searches for signals from theorised particles such as axions and axion-like particles.
Dr Sally Shaw said:
This is definitely the most exciting thing LZ has seen so far but we’ll need to work hard now to analyse more data to determine if this is a real dark matter signal. If we see more interactions that fit the bill, we’re onto something. We’re intrigued because that ‘something’ would be our first steps in understanding a huge missing piece of the puzzle of our universe!
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The Scottish Science Advisory Council announces membership appointments.
Professor of Biological and Soft Matter Physics, Cait MacPhee, has been appointed a member of the Scottish Science Advisory Council (SSAC).
The SSAC is Scotland’s highest-level science advisory body, providing independent advice and recommendations on science strategy, policy and priorities to the Scottish Government. It plays a vital role in ensuring that policy decisions are informed by the latest scientific evidence and expertise.
Four University colleagues have taken up roles on the Scottish Science Advisory Council.
Professor Cait MacPhee said:
I am absolutely delighted to join the SSAC. It's a privilege to represent the scientific community and support the development of evidence-informed policies in Scotland.
Three astronomers from the School of Physics and Astronomy have been awarded prizes by a major space telescope consortium, the Euclid Consortium.
With over 3,600 scientists and engineers, the Euclid Consortium (EC) is one of the world’s largest astronomy collaborations. It is tasked with analysing data from the European Space Agency’s Euclid satellite. Euclid is unravelling the mysteries of Dark Matter and Dark Energy by mapping galaxies across huge swathes of the sky out to vast distances. The UK is a leading nation within the EC, and Edinburgh scientists in particular play a major role in this historic mission.
At the 2026 annual EC meeting, three Edinburgh astronomers from the School’s Institute for Astronomy were awarded highly prestigious Special Talent and Recognition (STAR) Prizes for their key individual contributions to Euclid.
James Fawcett won the Outreach Award for his outstanding outreach achievements and leadership, becoming the driving force behind Euclid outreach in the UK.
James said:
Public engagement is an essential part of the scientific process and funding it matters more than ever. I was delighted to win this award, which gave me the opportunity to chat about our outreach efforts in the UK and raise awareness of various projects from the past year. This included partnerships with STFC, Dynamic Earth, Edinburgh Science and Glasgow Science Centre. Our collaborations led to an escape room style workshop for primary schools developed by MSc Science Communication placement students, planetarium show content, temporary exhibitions, online 'Meet the Scientist' style sessions and more.
Alex Hall won the Leadership & Coordination Award for his exemplary leadership of the Weak Lensing Science Working Group and the 3x2pt Pipeline Group, and his passion and dedication to the Consortium.
Alex commented:
It is a great privilege to have been awarded this prize by such a prestigious collaboration. The fact that three prizes have been awarded to Edinburgh scientists underscores the high regard held for the Institute for Astronomy by the international research and innovation community. I am very excited to use Euclid’s data to make new discoveries about our Universe, particularly the nature of Dark Matter and Dark Energy.
Maria Tsedrik won the Student Award for her exceptional scientific contributions to Euclid’s DR1 theoretical modelling for beyond LCDM cosmologies, and for her broader impact on Euclid DR1 readiness.
Maria said:
I am very grateful to have my work recognised within such an enormous collaboration dedicated to tackling the biggest unsolved mysteries in cosmology. Right now is an extremely exciting time to shed light on the dark sector of the Universe with the power of Euclid, both the instrument itself and the wonderful community of brilliant scientists behind it. I look forward to the scientific breakthroughs that will emerge from this incredible mission in the nearest future!
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Astronomers have discovered a third exoplanet orbiting a young star known as Beta Pictoris – located around 63 light years away from Earth – a study reveals.
The newly discovered planet, called Beta Pictoris d, is 100 times fainter than Beta Pictoris b – the first planet to be discovered in the system.
Researchers also found that the newcomer has a much wider orbit than its planetary friends - Beta Pictoris b and Beta Pictoris c. Moreover, while the first two planets are each around ten times the mass of Jupiter, Beta Pictoris d is only 2.4 times more massive than Jupiter, making it one of the lightest ever planets imaged from the ground.
An international team of scientists, including researchers from Edinburgh’s Institute for Astronomy, uncovered the faint planet in new images from the European Southern Observatory's Very Large Telescope (ESO’s VLT) in Chile, as well as in more than a decade’s worth of archive data.
The team initially wanted to take a closer look at Beta Pictoris b, to observe how it had changed over time. However, when they started analysing the images of the system, they noticed something else that led the team down an entirely new path.
Astronomers first detected Beta Pictoris d using ERIS – a powerful infrared camera mounted on ESO’s VLT – and built by the Science and Technology Council’s Astronomy Technology Centre (UK ATC) based in Edinburgh.
To confirm the nature of their detection, the team looked through ESO’s archive of past observations and found the new planet, Beta Pictoris d, in multiple images dating back as far as 11 years ago.
Related research
An independent team led by the University of California also detected Beta Pictoris d using the James Webb Space Telescope. Their findings are published alongside these results in The Astrophysical Journal Letters.
The discovery brings the total number of known planets in the Beta Pictoris system to three. Making it only the second system where more than two planets have been directly imaged along with the star HR 8799.
The research highlights how cutting-edge instrumentation, combined with astronomical archives spanning decades, can uncover worlds that have remained hidden in plain sight.
The study, published in The Astrophysical Journal Letters, was chiefly funded by the Science and Technology Facilities Council.
Dr Ben Sutlieff, study co-lead and Postdoctoral Research Associate, Institute for Astronomy, University of Edinburgh, said:
This was a serendipitous discovery. Star systems with multiple imaged exoplanets are the ‘holy grails’ of discoveries because they can teach us a lot about what different exoplanets are like in the same formation environment.
Professor Beth Biller, co-lead of the paper and Personal Chair of Exoplanet Characterisation, University of Edinburgh, said:
Planets seem to have friends. Many of the famous directly imaged exoplanet systems seem to have multiple giant planets in the same system. It is likely there are even more lower mass planets hiding in these systems that might be revealed in future.
Markus Bonse, ESO astronomer and other co-lead of the study, recalls saying when looking at the data:
There’s something else there, did you see it? The new planet is 100 times fainter than Beta Pictoris b, the famous planet in the same system, making it the faintest exoplanet ever imaged directly from Earth.
William Taylor, instrument scientist at UK ATC, said:
Detecting a planet this faint next to a much brighter star is an immense technical challenge, and it is rewarding to see an instrument we built here in Edinburgh helping astronomers uncover new worlds.
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Astronomers, engineers and public engagement professionals brought Euclid: The Dark Universe Detective to more than 10,000 visitors at this year’s Royal Society Summer Science Exhibition.
The Royal Society chose to showcase the latest research from the European Space Agency (ESA)’s Euclid space telescope at its prestigious annual Summer Science Exhibition. The free, public event, which took place from 30 June to 5 July, invited world leading researchers from universities and science institutions from across the UK to showcase the latest cutting-edge science and research through hands-on activities, talks and interactive exhibits.
Led by the University of Edinburgh, in partnership with the University of Sussex and The Open University, the exhibit told the story of the Euclid mission as a ‘dark Universe detective’, shedding light on the mystery of missing matter. By mapping the sky in incredible detail, Euclid will uncover cosmic clues that will reveal information about the nature of dark matter and dark energy, helping scientists understand how the Universe evolved.
Through a series of interactives, visitors had the opportunity to journey through the visible and dark Universe, search for hidden dark matter, become massive cosmic objects to warp spacetime, make citizen science discoveries of gravitational lenses and zoom endlessly into Euclid’s stunning images of space!
The exhibition also featured some fantastic talks and performances. Professor Andy Taylor, from the University of Edinburgh, who leads the UK’s Euclid data analysis team and the mission’s gravitational lensing data analysis, was in conversation with Dr Will Coulton for ‘Cosmic Detectives’, chaired by Professor Lucie Green. An incredible drag reinterpretation of the Euclid mission was performed by Charlie Wood for ‘A queer tour of the Summer Science Exhibition’.
The exhibition showcased the breadth of research and public engagement talent, from MSc Science Communication and PhD students to postdocs and senior professors. It also highlighted the benefits of collaboration between internal colleagues across the University, and external partners, including other Universities, science centres and cultural institutions.
James Fawcett, Euclid UK Public Engagement Lead based at the University of Edinburgh, said:
This is a really exciting time for the Euclid space telescope, with our national outreach programme growing just as the first cosmological results from the mission approach ever closer! I’m looking forward to seeing how our attendance at Summer Science can be the catalyst that extends our reach even further.
Euclid: The Dark Universe Detective will tour flagship events and science festivals in the coming months ahead of the space telescope’s first data release in the autumn and some exciting cosmological results which are expected next summer. Learn more in the link below, which also contains an online exhibition.
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A dazzling interstellar comet which recently visited Earth’s Solar System could be much older than the sun, a study reveals.
The research shines new light on the history of the comet – known as 31/ATLAS – as well its origins and composition.
A team of astronomers, led by the University of Edinburgh in partnership with the Universities of Liège, Belgium and Helsinki used the European Southern Observatory's Very Large Telescope (ESO's VLT) to study 31/ATLAS’s chemical makeup.
The findings indicate that the comet is around 12 billion years old and was formed outside of our own Solar System.
31/ATLAS
Interstellar comets are icy bodies that were formed outside our solar system and occasionally pass through our planetary system on an open trajectory before exiting back into deep space.
They are thought to hold material from the time when the Sun and our planets were forming.
3I/ATLAS is only the third interstellar comet ever discovered, after scientists discovered comets 1I/ʻOumuamua and 2I/Borisov in 2017 and 2019 respectively.
It was found as it was approaching the Sun, spending enough time in our Solar System for the team to study it in detail.
While it was difficult to measure the composition of the first two comets – in 1I/ʻOumuamua astronomers didn’t detect any gas and 2I/Borisov was too faint – this was not the case for 3I/ATLAS.
Brilliant radiance
Thanks to its unprecedented brightness, the team were able to measure the ratios of carbon and nitrogen isotopes found within the cyanide molecules present in the gas surrounding the comet.
These ratios are known to be good indicators of a comet’s origin, as they are sensitive to the physical conditions of the environment in which the comet was formed and are not expected to change much as the comet travels through space, experts say.
Related research
A similar study, led by NASA Goddard Space Flight Centre and published in Nature found a similar isotopic ratio of carbon, as well as elevated levels of deuterium, also called heavy hydrogen. The study used data from the James Webb Space Telescope (JWST) and was a joint project between the US, European and Canadian space agencies.
Cosmic findings
The current paper, published in Nature Astronomy, indicate that 3I/ATLAS likely formed around an old, low-metallicity star. This star is thought to have formed when the Universe was much younger and less chemically rich than it is now.
The team concluded that 3I/ATLAS therefore originated around a star much older than the Sun.
Dr Cyrielle Opitom, from the School of Physics and Asronomy, said:
The field of interstellar comets is still very new, and we don’t really know what to expect. Every time a new one is discovered, we have new surprises. However, these results are very encouraging and could hold the key to a better understanding of the variety of conditions in which the formation of planetesimals – the building blocks of planets – happen.
Astronomers in Edinburgh join colleagues around the world celebrating the start of the NSF–DOE Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST).
The night of 29 June saw the start of the Rubin LSST, an astronomical sky survey that has been dubbed “the cosmic movie” because of the unprecedented time-resolved view of the Universe that it will provide.
For the next ten years, the LSST will capture the entire southern sky to create an ultra-wide, ultra-high-definition time-lapse record of our Universe. This movie will help us solve some of the Universe’s biggest mysteries – such as the nature of dark energy, and the evolution of the solar system, Milky Way, and galaxies across cosmic time.
As a major international partner of the US-led Rubin Observatory, UK’s involvement is facilitated through a multi-million-pound investment by the Science and Technology Facilities Council (STFC). Formed in 2014, the LSST:UK Consortium is made up of 36 partner institutions representing all major UK astronomy research groups. Researchers and software developers across the UK are addressing scientific and technical challenges posed by this revolutionary observatory.
During its 10-year survey, Rubin will catalogue an estimated 17 billion stars and 20 billion galaxies, plus millions of events that change in the sky each night. With the survey expected to create up to 500 petabytes of data in its lifetime, the UK is playing a significant role in the management and processing of this unprecedented dataset. The UK's LSST data facility will process 25% of the data from Rubin, turning raw images of the sky into the calibrated data products with which astronomers can do science, and will operate an Edinburgh-based data centre capable of supporting analysis of those data products by 20% of the international LSST community.
The Edinburgh data centre also hosts the Lasair event broker, a sophisticated software system supporting the near-real-time analysis of the alerts that Rubin issues whenever it detects a moving or time-varying celestial source. This alert stream - which can comprise millions of alerts per night and which includes a wide range of astrophysical objects, from nearby asteroids to distant supernovae - started flowing in February, ahead of today's formal start of the 10-year LSST.
Professor Bob Mann, Professor of Survey Astronomy at the University of Edinburgh, is the Project Leader for UK participation in the Rubin LSST: He said:
Today marks the start of the 10-year LSST, but it is more like the mid-point of our UK project. Researchers in the UK have been preparing for more than a decade for the data that is starting to flow today and the contributions we are making will enhance the science that can be done with it over the coming decade or more by astronomers around the world.
Professor Grahame Blair, Executive Director of Programmes at STFC, said:
Today marks the beginning of a new era in astronomy. Together with our partners, UK scientists, engineers and software experts, STFC is excited to be part of one of the most ambitious scientific projects ever undertaken. The discoveries made over the next decade will inspire future generations, deepen our understanding of the cosmos, and reinforce the UK's position at the forefront of astronomical research.
Congratulations to Prof Davide Michieletto on securing an ERC Proof of Concept Grant.
Prof Davide Michieletto has been awarded a highly competitive European Research Council (ERC) Proof of Concept (PoC) Grant to explore the innovation potential of research arising from his ERC-funded project on “Topologically Active Polymers”, a new area of research at the interface of soft matter physics and biology.
The ERC Proof of Concept Grant is available exclusively to researchers who already hold an ERC award and aims to help transform frontier research discoveries into societal and commercial innovations. The funding supports researchers in verifying and developing the innovation potential of ideas emerging from their ERC-funded work by funding activities such as experimentation, technical validation, intellectual property assessment, and collaboration with industrial, policy, or societal stakeholders.
Prof Michieletto's grant will support the technical and commercial development of DNA nanotechnology aimed at solving outstanding challenges in early cancer diagnostic.
By supporting the next stage of development, the ERC Proof of Concept Grant will help position the project for future translation into practical applications, products and commercial ventures, in turn maximising the impact of the original ERC-funded research.