{"id":389180,"date":"2025-09-01T12:22:13","date_gmt":"2025-09-01T12:22:13","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/389180\/"},"modified":"2025-09-01T12:22:13","modified_gmt":"2025-09-01T12:22:13","slug":"scientists-finally-solve-the-mystery-of-the-suns-fastest-particles","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/389180\/","title":{"rendered":"Scientists Finally Solve the Mystery of the Sun\u2019s Fastest Particles"},"content":{"rendered":"

\t\t\"Solar<\/a>ESA\u2019s Solar Orbiter revealed how the Sun launches two distinct streams of high-energy electrons, solving a key mystery and advancing space weather protection. Credit: ESA & NASA\/Solar Orbiter\/STIX & EPD<\/p>\n

The Sun acts as the Solar System\u2019s ultimate particle accelerator, hurling out streams of high-speed electrons.<\/strong><\/p>\n

Thanks to ESA\u2019s Solar Orbiter, scientists have traced these energetic electrons back to their solar origins, revealing two distinct types: sudden bursts from solar flares and prolonged waves from massive eruptions called coronal mass ejections (CMEs).<\/p>\n

Solar-Powered Particle Accelerator<\/p>\n

The Sun acts as the Solar System\u2019s ultimate particle accelerator. It pushes electrons to speeds approaching that of light, hurling them into space and filling the Solar System with what scientists call \u2018Solar Energetic Electrons\u2019 (SEEs).<\/p>\n

Using ESA\u2019s Solar Orbiter<\/a> spacecraft, researchers have now tracked these high-energy electrons back to their origin on the Sun. The results show that there are two distinct types of SEE events. One is linked to powerful solar flares (eruptions from smaller, active regions on the Sun\u2019s surface), while the other comes from massive outbursts of hot plasma in the Sun\u2019s atmosphere (called \u2018coronal mass ejections\u2019, or CMEs).<\/p>\n

\u201cWe see a clear split between \u2018impulsive\u2019 particle events, where these energetic electrons speed off the Sun\u2019s surface in bursts via solar flares, and \u2018gradual\u2019 ones associated with more extended CMEs, which release a broader swell of particles over longer periods of time,\u201d says lead author Alexander Warmuth of the Leibniz Institute for Astrophysics Potsdam (AIP), Germany.<\/p>\n

\"Solar<\/a>Solar Orbiter observed more than 300 bursts of \u2018Solar Energetic Electrons\u2019 between November 2020 and December 2022. For the first time, we clearly see the connection between the energetic electrons in space and their sources on the Sun. The energetic electrons are launched by two distinct sources: solar flares (blue dots) and coronal mass ejections (red dots). Solar flares release quick bursts of energetic electrons, whereas coronal mass ejections release broader swells of energetic electrons more gradually. Credit: ESA & NASA\/Solar Orbiter\/STIX & EPD
\nA Clearer Connection<\/p>\n

Scientists had long suspected that two categories of SEE events existed, but Solar Orbiter\u2019s unique vantage point made it possible to confirm this in detail. The spacecraft observed far closer to the Sun than earlier missions and captured an unusually large set of events, allowing researchers to see how the electrons formed and escaped.<\/p>\n

\u201cWe were only able to identify and understand these two groups by observing hundreds of events at different distances from the Sun with multiple instruments \u2013 something that only Solar Orbiter can do,\u201d adds Alexander. \u201cBy going so close to our star, we could measure the particles in a \u2018pristine\u2019 early state and thus accurately determine the time and place they started at the Sun.\u201d<\/p>\n

\"Solar<\/a>Solar Orbiter observed this solar flare on November 11, 2022, with its Extreme Ultraviolet Imager (EUI) and Spectrometer\/Telescope for Imaging X-rays (STIX) instruments.
The EUI footage (yellow) shows million-degree gas in the Sun\u2019s atmosphere. A narrow ejection of gas from the flare called a solar jet, can be clearly seen heading towards the bottom right of the inset.
Solar flares release electrons both outwards into space and inwards towards the Sun\u2019s surface. When they hit the Sun\u2019s surface, they generate X-rays. This X-ray emission, recorded by STIX, is overlaid in blue.
Credit: ESA & NASA\/Solar Orbiter\/EUI & STIX
\nLargest SEE Study Yet<\/p>\n

The study is the most comprehensive of SEE events to date, and produces a catalogue<\/a> that will only grow through Solar Orbiter\u2019s lifetime. It used eight of Solar Orbiter\u2019s ten instruments to observe more than 300 events between November 2020 and December 2022.<\/p>\n

\u201cIt\u2019s the first time we\u2019ve clearly seen this connection between energetic electrons in space and their source events taking place at the Sun,\u201d adds co-author Frederic Schuller, also of AIP.<\/p>\n

\u201cWe measured the particles in situ \u2013 that is, Solar Orbiter actually flew through the electron streams \u2013 using the probe\u2019s Energetic Particle Detector, while simultaneously using more of the spacecraft\u2019s instruments to observe what was happening at the Sun. We also gathered information about the space environment between the Sun and spacecraft.\u201d<\/p>\n

\"Coronal<\/a>Solar Orbiter observed this coronal mass ejection (CME) on November 19, 2022. A CME is a vast eruption of billions of tonnes of plasma and accompanying magnetic fields from the Sun\u2019s outer atmosphere.
The Metis instrument images the Sun\u2019s outer atmosphere by artificially covering its bright disc, similar to what happens during a total solar eclipse. In this movie, the Sun\u2019s size and position are depicted by the white circle.
Credit: ESA & NASA\/Solar Orbiter\/Metis
\nFlight Delays in Space<\/p>\n

The researchers detected the SEE events at different distances from the Sun. This let them study how the electrons behave as they travel through the Solar System, answering a lingering question about these energetic particles.<\/p>\n

When we spot a flare or a CME, there\u2019s often an apparent lag between what we see taking place at the Sun, and the release of energetic electrons into space. In extreme cases, the particles seem to take hours to escape. Why?<\/p>\n

\u201cIt turns out that this is at least partly related to how the electrons travel through space \u2013 it could be a lag in release, but also a lag in detection,\u201d says co-author and ESA Research Fellow Laura Rodr\u00edguez-Garc\u00eda. \u201cThe electrons encounter turbulence, get scattered in different directions, and so on, so we don\u2019t spot them immediately. These effects build up as you move further from the Sun.\u201d<\/p>\n

\"Solar<\/a>Solar Orbiter has a suite of ten science instruments to study the Sun. There are two types: in situ and remote sensing. The in situ instruments measure the conditions around the spacecraft itself. The remote-sensing instruments measure what is happening at large distances away. Together, both sets of data can be used to piece together a more complete picture of what is happening in the Sun\u2019s corona and the solar wind. Credit: ESA-S.Poletti
\nTurbulence in Solar Space<\/p>\n

The space between the Sun and the planets of the Solar System isn\u2019t empty. A wind of charged particles constantly streams out from the Sun, dragging the Sun\u2019s magnetic field with it. It fills space and influences how the energetic electrons travel; rather than being able to go where they like, they are confined, scattered, and disturbed by this wind and its magnetism.<\/p>\n

The study fulfills an important goal of the Solar Orbiter: to continuously monitor our star and its surroundings, tracing ejected particles back to their sources at the Sun.<\/p>\n

\u201cThanks to Solar Orbiter, we\u2019re getting to know our star better than ever,\u201d says Daniel M\u00fcller, ESA Project Scientist for Solar Orbiter. \u201cDuring its first five years in space, Solar Orbiter has observed a wealth of Solar Energetic Electron events. As a result, we\u2019ve been able to perform detailed analyses and assemble a unique database<\/a> for the worldwide community to explore.\u201d<\/p>\n

Keeping Earth Safe<\/p>\n

Crucially, the finding is important for our understanding of space weather, where accurate forecasting is essential to keep our spacecraft operational and safe. One of the two kinds of SEE events is more important for space weather: that connected to CMEs, which tend to hold more high-energy particles and so threaten far more damage. Because of this, being able to distinguish between the two types of energetic electrons is hugely relevant for our forecasting.<\/p>\n

\u201cKnowledge such as this from Solar Orbiter will help protect other spacecraft in the future, by letting us better understand the energetic particles from the Sun that threaten our astronauts and satellites,\u201d adds Daniel. \u201cThe research is a really great example of the power of collaboration \u2013 it was only possible due to the combined expertise and teamwork of European scientists, instrument teams from across ESA Member States, and colleagues from the US.\u201d<\/p>\n

Vigil and the Next Frontier<\/p>\n

Looking ahead, ESA\u2019s Vigil mission<\/a> will pioneer a revolutionary approach, operationally observing the \u2018side\u2019 of the Sun for the first time, unlocking continuous insights into solar activity. To be launched in 2031, Vigil will detect potentially hazardous solar events before they come into view as seen from Earth, giving us advance knowledge of their speed, direction and chance of impact.<\/p>\n

Our understanding of how our planet responds to solar storms will also be investigated further with the launch of ESA\u2019s Smile mission<\/a> next year. Smile will study<\/a> how Earth endures the relentless \u2018wind\u2019, and sporadic bursts, of fierce particles thrown our way from the Sun, exploring how the particles interact with our planet\u2019s protective magnetic field.<\/p>\n

Reference: \u201cCoSEE-Cat: A Comprehensive Solar Energetic Electron event Catalogue obtained from combined in situ and remote-sensing observations from Solar Orbiter \u2013 Catalogue description and first statistical results\u201d by A. Warmuth, F. Schuller, R. G\u00f3mez-Herrero, I. Cernuda, F. Carcaboso, G. M. Mason, N. Dresing, D. Pacheco, L. Rodr\u00edguez-Garc\u00eda, M. Jarry, M. Kretzschmar, K. Barczynski, D. Shukhobodskaia, L. Rodriguez, S. Tan, D. Paipa-Leon, N. Vilmer, A. P. Rouillard, C. Sasso, S. Giordano, G. Russano, C. Grimani, F. Landini, C. Mac Cormack, J. A. J. Mitchell, A. Fedeli, L. Vuorinen, D. Lario, H. A. S. Reid, F. Effenberger, S. Musset, K. Riebe, A. Galkin, K. Makan, S. Reusch, A. Vecchio, O. Dudnik, S. Krucker, M. Maksimovic, J. Rodr\u00edguez-Pacheco, M. Romoli and R. F. Wimmer-Schweingruber, 32 August 2025, Astronomy & Astrophysics.
DOI: 10.1051\/0004-6361\/202554830<\/a><\/p>\n

Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.<\/p>\n

Never miss a breakthrough: Join the SciTechDaily newsletter.<\/a><\/b><\/p>\n","protected":false},"excerpt":{"rendered":"ESA\u2019s Solar Orbiter revealed how the Sun launches two distinct streams of high-energy electrons, solving a key mystery…\n","protected":false},"author":2,"featured_media":389181,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3844],"tags":[3014,70,29394,413,12131,14741,16,15],"class_list":{"0":"post-389180","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-european-space-agency","9":"tag-science","10":"tag-solar-orbiter","11":"tag-space","12":"tag-space-weather","13":"tag-sun","14":"tag-uk","15":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/115129021217081786","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/389180","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=389180"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/389180\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/389181"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=389180"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=389180"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=389180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}