Tag: magnetohydrodynamics

  • Our Best Look Yet at a Solar Flare

    Our Best Look Yet at a Solar Flare

    Scientists have unveiled the sharpest images ever captured of a solar flare. Taken by the Inouye Solar Telescope, the image includes coronal loop strands as small as 48 kilometers wide and 21 kilometers thick–the smallest ones ever imaged. The width of the overall image is about 4 Earth diameters. The captured flare belongs to the most powerful class of flares, the X class. Catching such a strong flare under the perfect observation conditions is a wonderful stroke of luck.

    Although astronomers had theorized that coronal loops included this fine-scale structure, the Inouye Solar Telescope is the first instrument with the resolution to directly observe structures of this size. Confirming their existence is a big step forward for those working to understand the details of our Sun. (Video and image credit: NSF/NSO/AURA; research credit: C. Tamburri et al.; via Gizmodo)

  • Zoom Into the Sun

    Zoom Into the Sun

    Fall into our nearest star in this gorgeous high-resolution view of the Sun. Taken by Solar Orbiter, a joint NASA-ESA mission, the image stretches from the fiery photosphere — full of filaments and prominences — to the wispy yet unbelievably hot corona. It’s well worth clicking through to zoom in and around the full size image. (Image credit: ESA & NASA/Solar Orbiter/EUI Team, E. Kraaikamp; via Gizmodo)

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  • Striations on the Sun

    Striations on the Sun

    One of the perpetual challenges for fluid dynamicists is the large range of scales we often have to consider. For something like a cloud, that means tracking not only the kilometer-size scale of the cloud, but the large eddies that are about 100 meters across and smaller ones all the way down to the scale of millimeters. In turbulent flows, all of these scales matter. That problem is even harder for something like the Sun, where the sizes range from hundreds of thousands of kilometers down to only a few kilometers.

    It’s those fine-scale features that we see captured here. This colorized image shows light and dark striations on solar granules. Scientists estimate that each one is between 20 and 50 kilometers wide. They’re reflections of the small-scale structure of the Sun’s magnetic field as it shapes the star’s hot, conductive plasma. (Image credit: NSF/NSO/AURA; research credit: D. Kuridze et al.; via Gizmodo)

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  • Compressing Jupiter’s Magnetosphere

    Compressing Jupiter’s Magnetosphere

    Shaped by its strong internal magnetic field and the incoming solar wind, Jupiter has the largest magnetosphere in the solar system. It also has highly active aurorae at its poles, though they are most visible in ultraviolet wavelengths. A new analysis of Juno’s data shows that on 6-7 December 2022, Jupiter’s magnetosphere got compressed, coinciding with aurorae six times brighter than usual. The compression itself came from a shock wave in the incoming solar wind. (Image credit: NASA/JPL; research credit: R. Giles et al.; via Eos)

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  • A Glimpse of the Solar Wind

    A Glimpse of the Solar Wind

    In December 2024, Parker Solar Probe made its closest pass yet to our Sun. In doing so, it captured the detailed images seen here, where three coronal mass ejections — giant releases of plasma, twisted by magnetic fields — collide in the Sun’s corona. Events like these shape the solar wind and the space weather that reaches us here on Earth. The biggest events can cause beautiful auroras, but they also run the risk of breaking satellites, power grids, and other infrastructure. (Image credit: NASA/Johns Hopkins APL/Naval Research Lab; video credit: NASA Goddard; via Gizmodo)

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  • A New Plasma Wave for Jupiter

    A New Plasma Wave for Jupiter

    Jupiter‘s North Pole has a powerful magnetic field combined with plasma that has unusually low electron densities. This combination, researchers found, gives rise to a new type of plasma wave.

    Ions in a magnetic field typically move parallel to magnetic field lines in Langmuir waves and perpendicularly to the field lines in AlfvΓ©nΒ waves — with each wave carrying a distinctive frequency signature. But in Jupiter’s strong magnetosphere, low-density plasma does something quite different: it creates what the team is calling an AlfvΓ©n-Langmuir wave — a wave that transitions from AlfvΓ©n-like to Langmuir-like, depending on wave number and excitation from local beams of electrons.

    Although this is the first time such plasma behavior has been observed, the team suggests that other strongly-magnetized giant planets — or even stars — could also form these waves near their poles. (Image credit: NASA / JPL-Caltech / SwR I/ MSSS/G. Eason; research credit: R. Lysak et al.; via APS)

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    See the Solar Wind

    After a solar prominence erupts, strong solar winds flow outward from the sun, carrying energetic particles that can disrupt satellites and trigger auroras if they make their way toward us. In this video, an instrument onboard the ESA/NASA’s Solar Orbiter captures the solar wind in the aftermath of such an eruption. The features seen here extended 3 solar radii and lasted for hours. The measurements give astrophysicists their best view yet of this post-eruption relaxation period, and the authors report that their measurements are remarkably similar to results of recent magnetohydrodynamics simulations, suggesting that those simulations are accurately capturing solar physics. (Video and image credit: ESA; research credit: P. Romano et al.; via Gizmodo)

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  • Bright Night Lights

    Bright Night Lights

    A coronal mass ejection from the Sun set night skies ablaze in mid-October 2024. This composite panorama shows a busy night sky over New Zealand’s South Island. A widespread red aurora was joined by a green picket-fence aurora and a host of other magnetohydrodynamic phenomena. To the left shines a bright Stable Auroral Red (SAR) arc. On the right near the Moon hangs the purple arc of a STEVE — strong thermal emission velocity enhancement. All of these auroras (and aurora-adjacent phenomena) take place when high-energy particles from the solar wind interact with molecules in our atmosphere. Which molecules they encounter determines the color of the aurora, and the shape depends, in part, on which magnetic lines the particles get funneled down. With strong solar storms like this one, auroras can reach far from the poles, and, as seen here, can show up in many varieties. (Image credit: T. McDonald; via APOD)

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  • Glimpses of Coronal Rain

    Glimpses of Coronal Rain

    Despite its incredible heat, our sun‘s corona is so faint compared to the rest of the star that we can rarely make it out except during a total solar eclipse. But a new adaptive optic technique has given us coronal images with unprecedented detail.

    A solar prominence dancing in the Sun's magnetic field lines.

    These images come from the 1.6-meter Goode Solar Telescope at Big Bear Solar Observatory, and they required some 2,200 adjustments to the instrument’s mirror every second to counter atmospheric distortions that would otherwise blur the images. With the new technique, the team was able to sharpen their resolution from 1,000 kilometers all the way down to 63 kilometers, revealing heretofore unseen details of plasma from solar prominences dancing in the sun’s magnetic field and cooling plasma falling as coronal rain.

    Coronal rain -- cooler plasma falling back down along magnetic lines.

    The team hope to upgrade the 4-meter Daniel K. Inouye Solar Telescope with the technology next, which will enable even finer imagery. (Image credit: Schmidt et al./NJIT/NSO/AURA/NSF; research credit: D. Schmidt et al.; via Gizmodo)

  • Seeing the Sun’s South Pole For the First Time

    Seeing the Sun’s South Pole For the First Time

    The ESA-led Solar Orbiter recently used a Venus flyby to lift itself out of the ecliptic — the equatorial plane of the Sun where Earth sits. This maneuver offers us the first-ever glimpse of the Sun’s south pole, a region that’s not visible from the ecliptic plane. A close-up view of plasma rising off the pole is shown above, and the video below has even more.

    Solar Orbiter will get even better views of the Sun’s poles in the coming months, perfect for watching what goes on as the Sun’s 11-year-solar-cycle approaches its maximum. During this time, the Sun’s magnetic poles will flip their polarity; already Solar Orbiter’s instruments show that the south pole contains pockets of both positive and negative magnetic polarity — a messy state that’s likely a precursor to the big flip. (Image and video credit: ESA & NASA/Solar Orbiter/EUI Team, D. Berghmans (ROB) & ESA/Royal Observatory of Belgium; via Gizmodo)

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