The research, led by geologists Bernard Charlier of the University of Liège and Olivier Namur of KU Leuven, rests on a specialised discipline known as experimental petrology. Because no spacecraft has ever returned samples from Mercury and no meteorite has ever been convincingly linked to the planet, scientists cannot simply analyse rock in the way they do for the Moon or Mars. Instead, they recreate the planet’s interior in miniature. Using high-pressure, high-temperature apparatus, the teams subjected synthetic mixtures approximating Mercury’s interior to temperatures between roughly 1,250 and 2,170 degrees Celsius, at pressures equivalent to those found deep within a rocky planet, and watched how carbon behaved as molten metal separated from molten silicate.

The logic of the approach follows from how all the terrestrial planets formed. Mercury, Venus, Earth and Mars each began as accumulating material from the disc of gas and dust surrounding the young Sun. The heat released during accretion, together with contributions from radioactive decay and giant impacts, was sufficient to melt the growing planets, producing global oceans of magma. This molten stage was decisive: as a magma ocean crystallised, it sorted elements between a dense metallic core sinking to the centre and a silicate mantle left behind above. The mantle later partially melted to generate the magmas that built the crust, and the gases exsolved during this early evolution may have formed the planet’s first atmosphere. Whatever the magma ocean stage decided, the planet inherited for the next four and a half billion years.

The key variable governing carbon’s fate turned out to be oxygen. Geochemists quantify this with a parameter called oxygen fugacity, an effective measure of how oxidising or reducing the environment is. Under relatively oxidising conditions, the experiments showed, carbon is strongly siderophile, meaning it prefers dissolving in metallic iron and follows the metal down into the core. Earth, which formed under comparatively oxidising conditions, exemplifies this behaviour. Mercury, however, is the most reduced of the terrestrial planets, its rocks remarkably poor in oxidised iron. Under those highly reducing conditions, the experiments revealed that carbon becomes far less attracted to metal and instead stays dissolved in the silicate magma.

That single shift in chemical affinity has dramatic consequences. As the reduced magma ocean cooled and crystallised, the carbon it hosted could no longer remain dissolved and precipitated as graphite, the soft, low-density crystalline form of pure carbon. Because graphite is too light to sink through the molten silicate, it floated. Accumulating at the top of the magma ocean, it formed a primitive crust of graphite, a crust made not of silicate rock like every other planetary crust in the inner solar system, but of carbon. The team’s model indicates this primordial graphite crust was on the order of 40 to 120 metres thick, a figure that matches the carbon-rich surface layer of roughly 1 to 3 per cent by mass inferred from observations by NASA’s MESSENGER spacecraft, which orbited Mercury from 2011.

The primordial graphite crust did not survive intact. Meteorite bombardment and the vigorous volcanism that built Mercury’s younger volcanic plains disrupted and redistributed the carbon-rich layer, mixing it into the surface deposits we see today. This history helps explain why MESSENGER detected abundant carbon darkening Mercury’s terrain, a property that had previously been difficult to reconcile with any simple crustal model. The new experiments provide the missing physical mechanism: a flotation crust of graphite, generated by the planet’s own extreme chemistry rather than by any exotic delivery of carbon from outside.

The same experiments resolved a second, long-standing puzzle about Mercury’s interior. Geodetic data from MESSENGER show that the planet’s core is extraordinarily large, accounting for roughly 70 per cent of Mercury’s total mass, and yet it is less dense than pure iron would be. Something light must be dissolved in the metal. Carbon had been proposed as a candidate light element, and the idea was appealing: if carbon stayed in the core, it would simultaneously explain the density deficit and the surface graphite. The new measurements close that door. Under precisely the reducing conditions required to float a graphite crust, the core remains strikingly poor in carbon, containing less than 5,000 micrograms per gram, or less than 0.5 per cent. That concentration is far too low to account for the observed density shortfall.

The culprit, the researchers conclude, is primarily silicon, with sulphur playing a secondary role. These elements dissolve in metallic iron under reducing conditions and are light enough to depress the core’s density to the value MESSENGER measured. They carry an additional consequence with far-reaching implications: both silicon and sulphur substantially lower the melting point of iron alloy. That depression helps explain how Mercury’s core has remained at least partially liquid for 4.5 billion years, despite the planet’s small size and the steady loss of its primordial heat. A liquid, convecting layer in the core is the dynamo that sustains Mercury’s magnetic field, one of the surprising discoveries of the Mariner 10 and MESSENGER eras. The same light elements that lighten the core, in other words, may also be what keeps the planet’s generator running.

By tying Mercury’s extreme chemical reduction to both its graphite crust and its core composition, the work provides a unified framework that extends well beyond one planet. It speaks to the nature of the original, more massive proto-Mercury that some models propose existed before a giant impact stripped away much of its mantle. It informs the study of hypothetical super-Mercuries, dense rocky exoplanets detected around other stars whose interiors may follow similar rules. It bears on carbon-rich exoplanets generally, where reduced conditions might likewise produce graphite flotation crusts rather than carbon sequestered in cores. And it even reaches back to the early Earth, which accreted largely from reduced materials, meaning the partitioning behaviour measured in these experiments constrains how our own planet distributed its carbon between core, mantle, atmosphere and the biosphere that eventually depended on it.

The timing of the work is no accident. BepiColombo, a joint mission of the European Space Agency and the Japan Aerospace Exploration Agency, is entering the final phase of its long journey and will place two spacecraft in orbit around Mercury, carrying instruments far more sensitive than those of MESSENGER. As Charlier notes, future observations could confirm and quantify graphite as a major phase on Mercury’s surface, turning a laboratory inference into a measured planetary fact. If the orbiters detect the spectral signature and thickness of the carbon-rich layer the experiments predict, scientists will have a rare example of a planet whose earliest crust, core chemistry and magnetic history can all be traced back to a single parameter: how little oxygen was present when its magma ocean cooled, more than four billion years ago.

Subject of Research: Carbon distribution during Mercury's magma ocean evolution and the formation of its graphite crust and core composition

Article Title: How Mercury formed its graphite crust and core

Article References: How Mercury formed its graphite crust and core. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Mercury, graphite crust, magma ocean, experimental petrology, oxygen fugacity, planetary cores, MESSENGER, BepiColombo, silicon, sulphur, magnetic field, reduced planets

Last week, the BepiColombo spacecraft achieved a major milestone on the road to Mercury orbit insertion, releasing the two orbiters from the transfer module that had carried them across hundreds of millions of kilometers. The mission consists of two distinct spacecraft: the European Space Agency’s Mercury Planetary Orbiter, known as the MPO, and the Japan Aerospace Exploration Agency’s Mercury Magnetospheric Orbiter, the MMO. SwRI led the design and fabrication of NASA’s Strofio instrument, which is mounted on the MPO. When the orbiters separated from the transfer module, the protective covers were removed from Strofio, exposing the instrument’s sensors to space for the final leg of the journey. The start of the science mission is expected early next year.

Strofio is a neutral mass spectrometer specially designed to sample the sparse exosphere that surrounds Mercury, measuring the particles that emanate directly from the planet’s surface. The instrument is remarkably small for the science it promises: it is roughly the size of a basketball and weighs just over seven pounds. Despite its modest dimensions, Strofio is expected to give scientists a substantially better understanding of the surface composition and the space environment of Mercury, the smallest of the solar system’s rocky planets and the one that orbits closest to the Sun. The instrument is part of the SERENA suite of instruments aboard BepiColombo, a collection of sensors dedicated to studying the exchange of particles between the planet’s surface and its tenuous atmosphere.

Getting a spacecraft into orbit around Mercury is one of the most demanding feats of orbital mechanics ever attempted, and BepiColombo will be only the second mission to accomplish it, following NASA’s MESSENGER spacecraft, which operated at Mercury from 2011 to 2015. The difficulty stems from a fundamental property of the inner solar system: as a spacecraft travels toward the Sun, solar gravity relentlessly accelerates it. Without intervention, a probe falling sunward would arrive at Mercury’s vicinity moving far too fast for the planet’s weak gravity to capture it into orbit. Multiple gravitational assists from Earth, Venus and Mercury itself are therefore needed to bleed off that excess energy and slow the craft down.

The consequences of this celestial braking maneuver are striking. Rather than the four to five months a simple flyby mission would require, an orbiting mission to Mercury takes almost ten years along a looping trajectory to achieve the precise speed needed for orbital insertion. Mission planners and commentators have long noted the counterintuitive comparison: it is in some respects easier to orbit Jupiter, a giant planet hundreds of millions of kilometers farther away, than Mercury. The BepiColombo mission, launched in 2018, is expected to enter orbit around Mercury in November 2026 and will achieve its final science orbit in early 2027, closing out an eight-year voyage across the inner solar system.

Dr. Frederic Allegrini, a staff scientist at SwRI, will help analyze the data that Strofio collects during its mission. He emphasizes the challenges posed by Mercury’s close proximity to the Sun, which make the orbital sampling approach not just convenient but essential. The surface of Mercury is so hot that landing a probe there and having it survive long-term is a formidable engineering challenge, he noted. A lander that could endure the extreme thermal environment would be fantastic from a scientific standpoint, but it would provide compositional information for only one location on the entire planet. Instead, with Strofio, the team will measure the surface composition by sampling the planet’s exosphere from orbit, an approach that yields more global knowledge of the surface rather than data from a single landing site.

The physics behind this technique is central to why Strofio exists at all. Mercury’s gravity is too weak to sustain a full, dense atmosphere like those of Earth, Venus or Mars. The planet can support only a tenuous outer atmosphere, called an exosphere, in which particles are so sparse that they rarely collide with one another and instead follow ballistic trajectories under gravity. This exosphere is not static; it is constantly replenished by processes that liberate material from the surface. Strofio will be sampling particles from the surface that get kicked up by mechanisms such as meteorite impacts and the solar wind, the continuous stream of charged particles flowing outward from the Sun. Because the exospheric particles originate at the surface, measuring their composition from orbit provides an indirect but planet-wide chemical census of the ground below.

Allegrini describes Mercury as an interesting object, kind of an oddball compared to the other planets. The planet is much denser than would otherwise be expected, and its core is disproportionately large relative to its size, a combination that has puzzled planetary scientists for decades. The team expects Strofio data to answer a significant number of scientific questions related to the planet’s surface composition, and they also suspect that some surprises await in the measurements. Any unexpected species detected in the exosphere could point to previously unrecognized surface minerals, unusual space-weathering processes, or exotic interactions between the solar wind and the airless terrain.

Allegrini will be joined in the analysis effort by Jared Schroeder, a postdoctoral researcher at SwRI, and together they will comb through the Strofio data looking for clues about Mercury’s origin story. Schroeder said the team is hoping to clear up some of the mysteries around the planet, including the composition of Mercury’s surface and how it interacts with the exosphere. The material that Strofio will measure comes directly from the surface, which makes the instrument’s observations a uniquely direct window onto the planet’s makeup. Understanding that composition, in turn, feeds into broader questions about how the innermost planet formed and evolved, and whether its outsized core reflects an unusual formation history, the loss of an early crust and mantle, or some combination of processes that shaped the young solar system.

The operational backbone of the mission spans multiple institutions on two continents. Mission operations for Strofio are based out of the University of Michigan, but SwRI will receive the data for scientific analysis, keeping the Texas-based institute at the center of the instrument’s science return. The BepiColombo spacecraft itself carries a name rich with history: it honors Giuseppe Colombo, the twentieth-century Italian scientist and mathematician who performed some of the first detailed studies of Mercury. Colombo’s calculations showed how to get a spacecraft into a solar orbit that would repeatedly encounter Mercury by using a gravity assist maneuver with Venus, an insight that underpins the very trajectory strategy the mission has now executed over its long, looping voyage. As the two orbiters settle into their final paths around the scorched little planet early next year, the basketball-sized spectrometer that spent nearly a decade in transit will finally get its chance to taste the exosphere and, through it, read the chemistry of Mercury itself.

Subject of Research: The Strofio neutral mass spectrometer aboard BepiColombo's Mercury Planetary Orbiter and its study of Mercury's exosphere and surface composition

Article Title: SwRI’s Strofio is gearing up to study Mercury’s surface

Article References: SwRI’s Strofio is gearing up to study Mercury’s surface. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Mercury, BepiColombo, Strofio, Southwest Research Institute, exosphere, mass spectrometry, Mercury Planetary Orbiter, planetary science, surface composition, solar wind, gravitational assists, ESA

Solar energetic particles are among the most hazardous phenomena in the solar system. Unlike the steady wind of charged particles that flows constantly from the Sun, these episodic bursts can accelerate electrons, protons and heavier ions to a substantial fraction of the speed of light, driven by solar flares and the shock waves ahead of coronal mass ejections. At Earth, our planet’s strong dipolar magnetic field and thick atmosphere protect life and infrastructure from the worst of these events, although intense storms can still disrupt satellites, radio communications and power grids. At Mercury, the picture is radically different. The planet has only a weak magnetic field, roughly one percent of Earth’s surface field strength, and essentially no atmosphere, so any particle that penetrates its magnetosphere strikes bare rock directly.

BepiColombo is ideally placed to study this environment. The mission, a collaboration between the European Space Agency and the Japan Aerospace Exploration Agency, is en route to orbit Mercury with two scientific spacecraft, the ESA-led Mercury Planetary Orbiter and the JAXA-led Mercury Magnetospheric Orbiter. To reach its destination, the combined stack has been performing a series of planetary flybys, using gravity assists at Earth, Venus and Mercury to shed energy and adjust its trajectory. During one of its close Mercury flybys, the spacecraft passed through the planet’s magnetospheric environment at a time when the Sun was unusually active, turning a routine trajectory-correction maneuver into an unplanned natural experiment.

As the spacecraft approached the planet, its particle and field instruments registered the signature of a solar energetic particle event in progress. Outside the magnetosphere, the sensors recorded intense fluxes of energetic electrons arriving from the Sun. But as BepiColombo crossed into the region dominated by Mercury’s magnetic field, the picture changed dramatically. The fluxes of solar energetic particles dropped sharply, revealing that the planet’s magnetosphere, despite its modest strength, was acting as a genuine shield, carving out a protective cavity in the otherwise hostile radiation environment. This planetary shielding effect had been predicted by models, but direct in situ evidence of it during a major solar particle event had remained scarce.

The shielding, however, is not complete, and the second half of the story is arguably more important. The measurements showed that while most of the incoming particle population was deflected around the planet, a significant fraction of the energetic particles found their way to low altitudes and precipitated onto the surface. Charged particles can enter a magnetosphere along open magnetic field lines that connect the polar and near-polar regions to interplanetary space, and they can also be scattered into loss orbits by wave-particle interactions and by the complex, asymmetric structure of Mercury’s field, which is offset from the planet’s center and strongly compressed on the sunward side.

This surface precipitation matters because it is a primary engine of space weathering on Mercury. When energetic protons and electrons strike the regolith, they sputter atoms out of surface minerals, break chemical bonds and alter the optical and chemical properties of the soil. Over geological time, this bombardment contributes to the darkening and modification of Mercury’s surface that scientists observe remotely. It also plays a role in generating the planet’s tenuous exosphere, the wispy envelope of atoms knocked loose from the ground, including species such as sodium, calcium and magnesium that telescopes have long observed glowing around the planet. Quantifying how many energetic particles actually reach the surface during a storm therefore places a direct constraint on how fast these processes operate.

The event also carries implications for understanding Mercury’s magnetosphere as a system. Unlike Earth’s relatively stable dipole, Mercury’s magnetosphere is small, comparable in scale to the planet itself, and highly dynamic. Its boundary, the magnetopause, sits close to the surface, and during periods of high solar wind pressure it can be pushed down until the planet’s dayside field lines are compressed against the crust. Reconnection between the interplanetary magnetic field and Mercury’s own field opens the magnetosphere to the solar wind, funneling energy and particles into the magnetotail and down to the surface. Observing the system during a solar energetic particle event, rather than during quiet conditions, reveals how this delicate balance responds to extreme forcing.

The BepiColombo observations provide a benchmark for testing magnetospheric models under exactly these extreme conditions. Simulations of Mercury’s space environment must reproduce both the shielding of the bulk of the solar energetic particle population and the leakage that allows a subset of particles to reach the surface. Getting this right is essential not only for Mercury science but also for the broader problem of planetary habitability and radiation environments. Mercury represents an end-member case: a planet with a magnetic field too weak to fully protect it and no atmosphere to absorb what gets through. Studying how much shielding such a field provides informs our understanding of exoplanets around active stars, where close-orbiting rocky worlds may face relentless particle bombardment.

There is also a practical dimension for the mission itself. BepiColombo’s cruise phase, with its series of flybys, exposes the spacecraft to the full spectrum of solar activity near the innermost planet, and the solar energetic particle event during the flyby subjected the spacecraft’s electronics to elevated radiation doses. Understanding the particle environment around Mercury is therefore a matter of operational survival as well as science. When the two orbiters separate and begin their science phase in orbit around the planet, they will encounter these storms regularly, and the flyby measurements offer an early, detailed preview of what they will face.

For now, the flyby observations stand as a vivid demonstration that even a small planetary magnetosphere leaves a measurable imprint on a solar storm, deflecting most of the incoming radiation while simultaneously channeling a damaging fraction of it down to the airless ground. As BepiColombo continues its journey and ultimately settles into orbit, scientists expect many more opportunities to watch Mercury’s magnetic shield at work, transforming a fleeting flyby measurement into a long-term record of how the innermost planet weathers the Sun’s worst moods.

Subject of Research: In situ observations of planetary shielding and surface precipitation of solar energetic particles in Mercury's magnetosphere during a BepiColombo close flyby.

Article Title: Planetary shielding and surface precipitation of solar energetic particles during BepiColombo’s close Mercury flyby

Article References: Kilpua, E. K. J., Vainio, R., Grande, M., Edwards, L., Laurenza, M., Esko, E., Lehtolainen, A., Palmroos, C., Gieseler, J., Oleynik, P., Ho, G., Lawrence, D. J., Liu, S. J., Massetti, S., Heyner, D., Pump, K., Sanchez-Cano, B., & Huovelin, J. (2026). Planetary shielding and surface precipitation of solar energetic particles during BepiColombo’s close Mercury flyby. Nature Astronomy. https://doi.org/10.1038/s41550-026-02914-6

Image Credits: AI Generated

DOI: 10.1038/s41550-026-02914-6

Keywords: BepiColombo, Mercury, solar energetic particles, magnetosphere, planetary shielding, space weathering, surface precipitation, solar storms, ESA, JAXA, exosphere, space weather

The particle and X-ray detector known as SIXS, designed and built in Finland, recorded the entire encounter. Now the measurements have been published in the journal Nature Astronomy, offering scientists their first close-range view of how solar energetic particles penetrate a planetary magnetosphere as small and feeble as Mercury’s and precipitate onto the planet itself. The results matter far beyond one small, scorched world. They provide a natural laboratory for understanding what happens when the most violent space weather strikes a magnetosphere, knowledge that directly informs how researchers assess the threat such storms pose to Earth’s own technological infrastructure and atmosphere.

Emilia Kilpua, principal investigator of SIXS and professor of space physics at the University of Helsinki, describes the flyby as an extraordinary stroke of fortune. The spacecraft came much closer to the surface than it will on its final science orbit, and a significant particle eruption occurred on the Sun at precisely that moment. Observing a powerful solar energetic particle event from a few hundred kilometers above Mercury, with instruments built to measure exactly such particles, is the kind of convergence mission scientists rarely dare to hope for. Instead of a quiet pass used mainly for steering and instrument testing, the team obtained a dataset of genuine scientific value that would have been impossible to schedule.

What SIXS revealed is striking. During the eruption, a large number of highly energetic particles reached Mercury’s surface across a wide area, sweeping over the planet rather than being funneled into narrow polar cusps alone. Mercury lacks a substantial atmosphere, so there is no cushion of air to absorb or slow the incoming radiation the way Earth’s atmosphere shields the surface. The planet’s magnetic field, moreover, is far weaker than Earth’s, and its magnetosphere is correspondingly much smaller, leaving it far more exposed to the full force of solar outbursts. The measurement therefore captures, in real time and at close range, how effectively a planetary magnetic field can or cannot shield the ground beneath it when the Sun unleashes its energy.

The physics of what happens next on the surface is central to why these observations matter. When energetic electrons and protons slam into the regolith, the loose layer of dust and rock that coats Mercury, they knock atoms and molecules loose from the surface material in a process called sputtering. The same impacts also generate X-ray radiation, as particles decelerate and excite atoms in the crust. Both the ejected particles and the induced X-rays carry chemical fingerprints of the surface composition. By measuring them, scientists can deduce what Mercury’s crust is made of and how the planet has been processed by billions of years of exposure to solar radiation and micrometeorite impacts. In orbit, several BepiColombo instruments will study these processes together, cross-referencing particle measurements from SIXS with X-ray observations of the surface from the MIXS instrument, in which Finland is also heavily involved, to build a coherent picture of the planet’s chemistry and evolution.

Rami Vainio, co-principal investigator of SIXS and professor of space physics at the University of Turku, emphasizes the comparative dimension of the findings. Mercury’s magnetic field is weaker than Earth’s and its magnetosphere much smaller, but the conditions at Mercury during this event resemble what Earth would experience if a powerful solar storm compressed its own magnetosphere. Under extreme conditions, Earth’s protective magnetic bubble can be squeezed inward dramatically, allowing energetic particles to penetrate far deeper into near-Earth space than usual, threatening satellites, disrupting radio communications, and in the most severe cases depositing energy into the upper atmosphere. Mercury during this flyby effectively demonstrated the end-member scenario, a magnetosphere overwhelmed by particle flux, showing how such radiation propagates and where it ultimately lands.

This is why the SIXS observations are expected to feed directly into space weather research focused on our own planet. Understanding how destructive particle radiation penetrates a planetary near-space environment and atmosphere during the most powerful space storms helps researchers refine models of radiation dose at aviation altitudes, satellite orbital predictions, and the behavior of Earth’s magnetosphere under stress. The data will also be used in the Center of Excellence in Space Resilience, funded by the Research Council of Finland for the period 2026 to 2033, in which both Kilpua’s and Vainio’s research groups participate. That program brings together space physicists, engineers, and resilience researchers to anticipate and mitigate the effects of extreme space weather on society, a concern that has grown as solar cycle activity has intensified and as modern infrastructure has become ever more dependent on satellites and sensitive electronics.

The broader context of the measurement is the remarkable journey that made it possible. BepiColombo was launched in October 2018 and has spent eight years traveling to Mercury, using a series of flybys of Earth, Venus, and Mercury itself to shed the orbital energy that a direct trajectory to the Sun’s neighborhood would make prohibitively expensive in fuel. In early September, the mission reached a milestone: the two orbiters, the Mercury Planetary Orbiter built by ESA and the Mercury Magnetospheric Orbiter built by JAXA, separated from the transfer module that had carried them across the solar system. The orbiters will enter Mercury’s orbit in November and separate from each other in December, beginning the dedicated science phase in complementary orbits. In total, the two spacecraft carry sixteen scientific instruments, forming the most comprehensive payload ever sent to the smallest and least explored of the solar system’s eight planets.

Mercury holds a special place in that exploration history, and a humble one. It is the planet closest to the Sun, which makes it exceptionally strongly affected by solar activity, yet only three spacecraft have ever studied it at close range. Mariner 10 flew past three times in the mid-1970s, revealing a heavily cratered world with a surprising magnetic field. MESSENGER orbited the planet from 2011 to 2015, mapping its surface, confirming water ice in permanently shadowed polar craters, and revealing an offset magnetic field whose origin remains debated. BepiColombo is only the third mission to visit and Europe’s first, carrying the ambition not merely to revisit these discoveries but to understand the planet as a coupled system: its interior, its surface, its thin exosphere, and its magnetosphere, all responding continuously to the ferocious output of the nearby Sun.

The fourth flyby measurements now published add an unexpected early dividend to that mission. Long before the orbiters begin their systematic observations, SIXS has demonstrated how solar energetic particles behave at Mercury, how widely they spread across the surface, and what that means for both planetary science and space weather forecasting. The lucky timing of the September 2024 encounter has effectively given the BepiColombo team a preview of the storm-driven physics they will study in detail from orbit, and given space weather scientists on Earth a benchmark dataset drawn from the most sun-exposed planet in the solar system. As the Sun approaches and passes through the active phase of its cycle, the lessons learned from Mercury’s bombardment will resonate directly in models that protect satellites, astronauts, and power grids far from the scorched world where they were first measured.

Subject of Research: Solar energetic particle precipitation onto Mercury's surface measured by the BepiColombo spacecraft during its close flyby

Article Title: BepiColombo measured Mercury's particle bombardment up close

Article References: BepiColombo measured Mercury's particle bombardment up close. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: BepiColombo, Mercury, solar energetic particles, space weather, magnetosphere, SIXS instrument, ESA, JAXA, solar storms, X-ray radiation, planetary shielding, Nature Astronomy