Magnetic avalanches power solar flares

European Space Agency

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A snapshot taken a second before a powerful solar flare was unleashed from the Sun, as seen in unprecedented detail by Solar Orbiter

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Credit: ESA & NASA/Solar Orbiter/EUI Team

Just as avalanches on snowy mountains start with the movement of a small quantity of snow, the ESA-led Solar Orbiter spacecraft has discovered that a solar flare is triggered by initially weak disturbances that quickly become more violent. This rapidly evolving process creates a ‘sky’ of raining plasma blobs that continue to fall even after the flare subsides.

The discovery was enabled by one of Solar Orbiter’s most detailed views of a large solar flare, observed during the spacecraft’s 30 September 2024 close approach to the Sun. It is described in a paper being published on Wednesday 21 January in Astronomy & Astrophysics.

Solar flares are powerful explosions on the Sun. They occur when energy stored in tangled magnetic fields is suddenly released through a process described as ‘reconnection’. In a matter of minutes, criss-crossing magnetic field lines of opposite direction break and then reconnect. The newly reconnected field lines can quickly heat up and accelerate million-degree plasma, and even high-energy particles, away from the reconnection site, potentially creating a solar flare.

The most powerful flares may start a chain of reactions that lead to geomagnetic storms on Earth, perhaps triggering radio blackouts, which is why it is so important to monitor and understand them.

But the fine-grained details of how exactly this humungous amount of energy is released so rapidly has remained poorly understood. This unprecedented set of new Solar Orbiter observations – from four of the mission’s instruments working in complement to provide the most complete picture of a solar flare ever made – finally has a compelling answer.

High-resolution imagery from Solar Orbiter’s Extreme Ultraviolet Imager (EUI) zoomed in to features just a few hundred kilometres across in the Sun’s outer atmosphere (its corona), capturing changes every two seconds. Three other instruments – SPICE, STIX and PHI – analysed a range of depths and temperature regimes, from the corona down to the Sun’s visible surface, or photosphere. Importantly, the observations enabled scientists to watch the buildup of events that led to the flare over the course of about 40 minutes.

“We were really very lucky to witness the precursor events of this large flare in such beautiful detail,” says Pradeep Chitta of the Max Planck Institute for Solar System Research, Göttingen, Germany, and lead author of the paper. “Such detailed high-cadence observations of a flare are not possible all the time because of the limited observational windows and because data like these take up so much memory space on the spacecraft’s onboard computer. We really were in the right place at the right time to catch the fine details of this flare.”

Magnetic avalanche in action

When EUI first started observing the region at 23:06 Universal Time (UT), about 40 minutes before peak flare activity, a dark arch-like ‘filament’ of twisted magnetic fields and plasma was already present, connected to a cross-shaped structure of progressively brightening magnetic field lines. (see Video 1: main movie)

Zooming in to this feature shows that new magnetic field strands appear in every image frame – equivalent to every two seconds or less. Each strand is magnetically contained, and they become twisted, like ropes. (see Video 2: X shapes)

Then, just like in a typical avalanche, the region becomes unstable. The twisted strands begin to break and reconnect, rapidly triggering a cascade of further destabilisations in the area. This creates progressively stronger reconnection events and outflows of energy, seen as sudden and increasing brightness in the imagery.

One particular brightening begins at 23:29 UT, followed by the dark filament disconnecting from one side, launching into space and at the same time violently unrolling at high speed. Bright sparks of reconnection are seen all along the filament in stunning high resolution as the main flare erupts at around 23:47 UT. (see Video 1: main movie)

“These minutes before the flare are extremely important and Solar Orbiter gave us a window right into the foot of the flare where this avalanche process began,” says Pradeep. “We were surprised by how the large flare is driven by a series of smaller reconnection events that spread rapidly in space and time.”

Scientists had already proposed a simple avalanche model to explain the collective behaviour of hundreds of thousands of flares on the Sun and other stars, but it had not been clear whether a single large flare could be described by an avalanche. What this result shows is exactly that – a flare is not necessarily a single coherent eruption but can be a cascade of interacting reconnection events.

Raining plasma blobs

For the first time, and thanks to the simultaneous measurements by Solar Orbiter’s SPICE and STIX instruments, Pradeep’s team have been able to explore in extremely high resolution how the rapid series of reconnection events deposits energy in the outermost part of the Sun’s atmosphere. 

Of particular interest is high-energy X-ray emission, which is a signature of where accelerated particles have deposited their energy. Given that accelerated particles can escape into interplanetary space and pose radiation hazards to satellites, astronauts, and even Earth-based technologies, understanding how this process occurs is essential for forecasting space weather. (see Video 4: STIX X-ray observations)

For the 30 September flare, the emission in ultraviolet to X-rays was already slowly rising when SPICE and STIX first started observing the region. The X-ray emission rose so dramatically during the flare itself – as reconnection events increased – that particles were accelerated to speeds of 40–50% the speed of light, equivalent to about 431–540 million km/h. Furthermore, the observations showed that the energy was transferred from the magnetic field to the surrounding plasma during these reconnection events.

“We saw ribbon-like features moving extremely quickly down through the Sun’s atmosphere, even before the main episode of the flare,” says Pradeep. “These streams of ‘raining plasma blobs’ are signatures of energy deposition, which get stronger and stronger as the flare progresses. Even after the flare subsides, the rain continues for some time. It’s the first time we see this at this level of spatial and temporal detail in the solar corona.” (see Video 3: raining plasma blobs, Video 1: main movie)

After the main phase of the flare, the original cross-shape of magnetic field lines is seen to relax in the EUI images, while STIX and SPICE saw the plasma start to cool down and particle emission decrease towards ‘normal’ levels. At the same time, PHI observed the imprint of the flare[NS1]  on the Sun’s visible surface, completing the three-dimensional picture of the event. (see Video 5: surface imprints)

“We didn’t expect that the avalanche process could lead to such high energy particles,” says Pradeep. “We still have a lot to explore in this process, but that would need even higher resolution X-ray imagery from future missions to really disentangle.”

“This is one of the most exciting results from Solar Orbiter so far,” says Miho Janvier, ESA’s Solar Orbiter co-Project Scientist. “Solar Orbiter’s observations unveil the central engine of a flare and emphasise the crucial role of an avalanche-like magnetic energy release mechanism at work. An interesting prospect is whether this mechanism happens in all flares, and on other flaring stars.”

“These exciting observations, captured in incredible detail and almost moment by moment, allowed us to see how a sequence of small events cascaded into giant bursts of energy,” says David Pontin of the University of Newcastle, Australia, who co-authored the paper.

He adds: “By comparing the EUI observations with magnetic-field observations, we were able to disentangle the chain of events that led to the flare. What we observed challenges existing theories for flare energy release and, together with further observations, will allow us to refine those theories to improve our understanding.”

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Notes for editors

 

A magnetic avalanche as the central engine powering a solar flare, by L. P. Chitta et al. is published in Astronomy and Astrophysics. DOI: 10.1051/0004-6361/202557253   https://www.aanda.org/10.1051/0004-6361/202557253

Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA. The Extreme Ultraviolet Imager (EUI) instrument is led by the Royal Observatory of Belgium (ROB). The Polarimetric and Helioseismic Imager (PHI) instrument is led by the Max Planck Institute for Solar System Research (MPS), Germany.  The Spectral Imaging of the Coronal Environment (SPICE) instrument is a European-led facility instrument, led by the Institut d'Astrophysique Spatiale (IAS) in Paris, France. The STIX X-ray Spectrometer/Telescope is led by FHNW, Windisch, Switzerland.

For more information, please contact:

ESA Media Relations, media@esa.int

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Journal

Astronomy and Astrophysics

DOI

10.1051/0004-6361/202557253 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

A magnetic avalanche as the central engine powering a solar flare

Article Publication Date

21-Jan-2026

Magnetic avalanche in action [VIDEO] 

Solar Orbiter’s most detailed view yet of a large solar flare, with filaments, raining plasma blobs, magnetic reconnection events and X-ray emission labelled

Zooming in on magnetic reconnection [VIDEO]

Solar Orbiter’s high-resolution images reveal the fine-grained detail of the ‘magnetic avalanche’ process that led up to the major solar flare of 30 September 2024.

Zooming in on raining plasma blobs [VIDEO] 

Solar Orbiter saw that, in the lead-up to a solar flare, twisted magnetic fields break and reconnect, creating an outflow of energy that subsequently rains down through the Sun’s atmosphere in ribbon-like streams.

X-rays blast from a solar flare [VIDEO] 

The evolution of X-ray emission during the M7.7 class solar flare recorded by Solar Orbiter in high resolution on 30 September 2024. The coloured contours outline the X-ray source regions detected by the mission’s X-ray Spectrometer/Telescope (STIX) instrument at the measured levels indicated in the key, superposed on top of the images recorded by the mission’s Extreme Ultraviolet Imager (EUI).

Surface imprint of a solar flare [VIDEO] 

Solar Orbiter's Polarimetric and Helioseismic Imager (PHI) instrument observed the wider-field imprint of the flare on the Sun’s visible surface (photosphere) in impressive detail, completing the three-dimensional picture of the flare.

Credit

ESA & NASA/Solar Orbiter/PHI Team

 

Layered hydrogen silicane for safe, lightweight, and energy-efficient hydrogen carrier

Researchers investigate layered hydrogen silicane as a new solid-state hydrogen carrier, paving the way for novel hydrogen storage systems

Institute of Science Tokyo

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Layered hydrogen silicane (L-HSi) represents a promising solid-state hydrogen carrier that can address the drawbacks of conventional hydrogen storage systems, while being cost-effective and sustainable.

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Credit: Institute of Science Tokyo

Hydrogen, a clean energy source, requires a highly reliable and safe storage system, which is currently lacking. Layered hydrogen silicane (L-HSi) is a promising, safe, lightweight, and energy-efficient solid-state hydrogen carrier with potential for practical utility. This material releases hydrogen when irradiated with low-intensity visible-light sources like sunlight or LEDs. L-HSi represents a new direction for hydrogen carrier system research.

Hydrogen is a promising fuel that can replace conventional fossil fuels as it emits no carbon dioxide during combustion or oxidation and can be produced from a wide range of sources. However, a hydrogen-based economy requires not only clean production but also safe and efficient hydrogen storage and transportation. Current systems pose several drawbacks: compressed hydrogen tanks have low hydrogen densities and pose explosion risks, while liquid hydrogen tanks require extremely low temperatures and considerable energy.

Ammonia is a well-known liquid hydrogen carrier with a high hydrogen density, but its dehydrogenation requires extensive energy and comes with issues such as corrosiveness and toxicity. To solve these issues, researchers have turned towards solid-state hydrogen carrier materials. Unfortunately, most solid-state alloys consist of heavy metals and have limited gravimetric hydrogen capacities.

In a breakthrough, a research team consisting of Mr. Hirona Ito and Professor Masahiro Miyauchi from Institute of Science Tokyo (Science Tokyo), Ms. Mio Nakai and Professor Hideyuki Nakano from Kindai University, and Professor Takahiro Kondo from the University of Tsukuba, Japan, discovered a new solid-state hydrogen carrier called layered hydrogen silicane (L-HSi). Hydrogen can be released from L-HSi by visible light irradiation under ambient temperature and pressure. Their findings were published online in the journal Advanced Optical Materials on December 29, 2025.

L-HSi consists of silicon and hydrogen in a 1:1 ratio and exhibits a high gravimetric hydrogen capacity of 3.44 wt.%. Unlike conventional hydrogen storage systems, it is a stable, solid-state hydrogen carrier that can release hydrogen simply by exposure to low-intensity light sources like sunlight or LEDs.

The researchers synthesized L-HSi via decalcification of CaSi2 in a reaction with HCl and tested its hydrogen release properties. They placed L-HSi powder under an argon atmosphere in a gas-flow-type reactor and irradiated it with a xenon lamp at ambient temperature and pressure. The optical bandgap of L-HSi is 2.13 eV, corresponding to a wavelength of 600 nm, which absorbs visible light. The light was turned on 10 minutes after the experiment began and turned off at the 60-minute mark. During irradiation, the researchers clearly observed gaseous hydrogen formation.

Further heating tests under a dark environment and detailed spectroscopic analysis confirmed that hydrogen release was not due to a photothermal process, but instead, driven by bandgap excitation of L-HSi. Specifically, hydrogen was released when irradiated with wavelengths below 600 nm. The material showed a maximum quantum efficiency of 7.3% at 550 nm.

The researchers also conducted long-term irradiation tests, where L-HSi was dispersed in an organic medium inside the dispersed reactor. Under extended visible-light exposure, about 46.7% of the bonded hydrogen atoms were released. The team also confirmed that hydrogen could be effectively produced using low-intensity, economical light sources, including sunlight and LEDs.

L-HSi is a promising solid-state hydrogen carrier that can open new possibilities for safe, lightweight, and energy-efficient hydrogen storage. Looking forward, their research will focus on improving its reversibility and scalability for practical applications.

 

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About Institute of Science Tokyo (Science Tokyo)
Institute of Science Tokyo (Science Tokyo) was established on October 1, 2024, following the merger between Tokyo Medical and Dental University (TMDU) and Tokyo Institute of Technology (Tokyo Tech), with the mission of “Advancing science and human wellbeing to create value for and with society.”

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Journal

Advanced Optical Materials

DOI

10.1002/adom.202502880 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Visible-Light-Driven Hydrogen Release from Layered Hydrogen Silicane

FOSSIL FOOLS

Last Czech deep coal mine closes as centuries-old industry reaches final day

Reuters | January 16, 2026 |

The ČSM coal mine in Stonava, owned by OKD. (Stock photo by davidjancik.)

The last Czech black coal shaft will shut at the end of January, closing the door on more than 250 years of deep mining and bringing to an end an industry that powered the rise of heavy industry in Central Europe.

The final tons are being hauled this month from kilometre‑deep shafts at the CSM mine in Stonava, near the Polish border, as low coal prices and Europe’s industrial and environmental transition sap demand for what was once the region’s most prized resource.

State‑owned OKD had been preparing to shut down three years ago, until Russia’s full‑scale invasion of Ukraine in 2022 sent energy markets surging and bought the mine a short‑lived extension.

For the last time miners rattle into the dark on the underground railway, headlamps flickering across steel supports as machines drill into the coal face.

“It is sad that the shaft is ending, it is hard work but good work,” said Grzegorz Sobolewski, a Polish miner who is considering taking another job across the border in Poland, where shafts remain in operation.

“I will miss the work, I will miss the shearer,” referring to the cutting machine that slices coal from the face as it moves along the seam. Behind him, another miner shouted instructions over the roar of machinery – a sound soon to disappear from the basin.

OKD director Roman Sikora said the mine’s depth had become its weakness.

“Global coal prices are low, while our mining costs are ever greater with the ever greater depths we go to,” he said.

Industrial heartland faces post-coal future

Mining in the Ostrava region began in the late 18th century and turned a rural corner of the Habsburg empire into an industrial enclave.

Investors, including the Rothschild family, financed major industrial projects such as railways, steelworks and supporting infrastructure, helping draw tens of thousands of labourers into what became a powerhouse of heavy industry.

The industry got another boost after Communist nationalisation in 1948. In the 1980s, more than 100,000 miners worked the basin and OKD produced up to 25 million metric tons a year.

Much of that world collapsed after 1989 when communist‑era heavy industry unraveled, pits closed one by one and tens of thousands of miners lost their livelihoods.

When privatised OKD went bankrupt a decade ago, the state took it over to wind it down. By last October, OKD had mined just 1.1 million tons for the year and shrunk its workforce to 2,300, with another 1,550 to be let go in the coming months.

Workforce reshaped by decades of mine closures

Economist Jan Belardi of the Technical University of Ostrava said the 1990s and early 2000s were the hardest years, as the region grappled with mass redundancies and the slow arrival of new industries.

Today unemployment stands at 6.6% – still above the national average, but far from the levels of the post‑communist slump, bolstered by retraining schemes and foreign investors drawn to the area after the Czech Republic joined the EU in 2004.

“Being on the border with Poland and Slovakia, this region had a significant influx of foreign direct investment such as South Korea’s Hyundai,” he said.

Mining also leaves behind an environmental impact, including polluted lagoons or ground drops, and former mines’ surface installations.

The region is getting 19 billion crowns ($907.96 million) from the EU’s Just Transition fund for transformation of regions affected by the bloc’s decarbonisation policies, Belardi said.

In Poland, black coal mining still employs 70,000, and unions have won pledges to keep mining until 2049. In western Czech Republic, surface mining of lignite is expected to continue for several more years.

OKD itself is trying to shape a future above ground. The company aims to stay active in coal trading and develop new ventures including a battery park, a data centre and a small methane‑fuelled power plant using gas seeping from the old shafts.

“We have quite grand plans with OKD in the future,” Sikora said.

($1 = 20.9260 Czech crowns)

(By Radovan Stoklasa and Jan Lopatka; Editing by Louise Heavens)

US approves Warrior Met Coal’s mining plans in Alabama

Staff Writer | January 15, 2026 | 

The preparation plant at Warrior Met Coal’s No. 4 met coal mine in Alabama. Credit: Warrior Met Coal.

The Office of Surface Mining Reclamation and Enforcement (OSM), a branch of the US Department of the Interior, has announced the federal approval of Warrior Met Coal’s mining plan for two sites in Tuscaloosa county, Alabama.

Leasing of the federal coal tracts was approved after OSM reviewed an EIS (environmental impact statement) prepared by the Bureau of Land Management and determined that the company’s mining plan adequately addresses “potential adverse environmental effects” and satisfies its responsibilities under the National Environmental Policy Act.

The approval authorizes the recovery of more than 53 million tons of metallurgical coal — a designated critical material under the Energy Act of 2020. Met coal is used to produce coke, an essential fuel for producing high-grade steel used in a wide range of applications, including manufacturing, automotive and construction.

Last year, US President Donald Trump signed an executive order to revive the country’s shrinking coal industry, rolling back key restrictions despite the fuel’s major role in climate change and pollution.

Trump directed federal agencies to lift Obama-era limits on coal mining, leasing and exports. He instructed the Interior Department to locate coal deposits on federal lands, remove barriers to mining, and fast-track leasing processes.

The mining plans for Warrior Met Coal’s Mine No. 4 and Blue Creek Mine No. 1 were advanced under Executive Order 14241, Immediate Measures to Increase American Mineral Production, and Executive Order 14261, Reinvigorating America’s Beautiful Clean Coal Industry.

“Coal recovered from the approval of these mining plans will go to America’s allies for steelmaking,” OSM director Lanny E. Erdos said in a news release. “This will strengthen our national security by ensuring stable supply chains for critical defense materials and reduces reliance on rivals like China.”

At Mine No. 4, Warrior expects to extract about 16.9 million tons of met coal, extending the life of mine by seven years to 2046, while employing approximately 425 employees annually. At Blue Creek Mine No. 1, the company plans to extract about 36.3 million tons, extending the life of mine by 14 years to 2067, while employing approximately 500 employees annually.

Coal recovery from these mines is anticipated to generate more than $400 million in average annual economic output, the company said.

Heavy rainfall disrupts Australian metallurgical coal supplies

Bloomberg News | January 16, 2026 | 

Isaac Plains mine in Queensland, Australia. Image: Golding Contractors

Heavy rainfall in northeast Australia has triggered floods that are hampering mine operations and disrupting supplies of metallurgical coal in the region.

Some coal miners have declared force majeure on portions of their shipments or warned customers of potential delays, according to traders, who asked not to be named as they are not authorized to speak to the media. The companies include Stanmore Resources Ltd., GM3 — a joint venture between Golden Energy and Resources and M Resources Ltd. — as well as Pembroke Resources Pty Ltd. and Fitzroy Coal Sales Pty Ltd.

Major miners such as Anglo American Plc and Glencore Plc have also been impacted but have not declared force majeure, the traders said. Argus Media reported that the road and rail disruptions had limited Glencore’s ability to supply copper concentrate for multiple days.

The disruptions follow an unusually wet start to summer in Queensland state, where some areas have seen rainfall close to their monthly precipitation averages weeks earlier than normal, due in part to Tropical Cyclone Koji.

Forecasters are warning that another weather system could form over the region from Monday, potentially compounding the impact on mining and transport operations.

Elsewhere in Australia, heavy rain is affecting parts of Victoria, with flash floods sweeping away cars on Great Ocean Road.

Stanmore, GM3, Pembroke, Fitzroy Coal, Anglo and Glencore did not immediately respond to requests for comment.

(By Paul-Alain Hunt and Katharine Gemmell)