Les images les plus précises de la face visible du Soleil montrent des tourbillons qui entraînent des éruptions capables d'endommager des satellites.

New images of the Sun’s visible surface reveal swirling patterns that drive eruptions capable of damaging satellites. Scientists have captured high-resolution images of the Sun showing small whirls that contribute to solar eruptions. These observations were made using the Daniel K. Inouye Solar Telescope, located near Haleakalā on the Hawaiian island of Maui. The telescope's four-meter mirror allows for unprecedented detail, resolving features as small as 19 kilometers across the Sun’s surface. The findings, published in Nature, represent the first clear experimental confirmation of Kelvin-Helmholtz instabilities in the photosphere, the visible layer of the Sun. These structures occur where two layers of plasma move at different speeds near regions dominated by magnetic fields. This phenomenon has been observed elsewhere, such as on Earth, Jupiter, and Saturn, but never with such clarity on the Sun itself. The images were taken on April 14, 2025, over a magnetically active area close to a sunspot. During three minutes, the telescope recorded a dynamic landscape filled with waves, dark bands, and small vortices that continuously formed and changed around magnetic concentrations. Researchers analyzed 47 of these whirls, some measuring just 25 kilometers and others reaching up to 170 kilometers in size. They moved at speeds up to three kilometers per second around magnetic regions. To ensure these formations weren’t merely visual anomalies, scientists compared their observations with computer simulations of the Sun. The models produced similar vortices with comparable dimensions, velocities, and behaviors. The explanation lies in how hot plasma flows toward areas with intense magnetic fields and gets deflected at their edges. Since neighboring layers don’t move at the same speed, the boundary begins to ripple and eventually forms small whirls. Some of these vortices merge together, while others generate even smaller ones. The result is continuous agitation that mixes magnetized plasma with less influenced material, promoting turbulence. Simulations suggest these vortices extend hundreds of kilometers into the Sun, potentially fragmenting hidden magnetic structures beneath the photosphere into smaller filaments. This mechanism plays a crucial role beyond appearance. The Sun’s magnetic field can twist and tangle, storing large amounts of energy. When this tension is released, it can fuel everything from minor flares to massive eruptions and coronal mass ejections. These eruptions launch plasma and radiation into space. If directed toward Earth, they can cause disruptions in satellite systems and power grids. The discovery offers new insights into how energy moves through the solar atmosphere and how magnetic fields interact with plasma. It could improve predictions of solar activity and its effects on space weather. As researchers continue analyzing data from the telescope, further understanding of these phenomena may lead to better forecasting tools for future solar events.