GoKawiilWherever two fluids slide past each other at different speeds, the boundary between them buckles, then curls, then rolls up into vortexes. It’s called the Kelvin-Helmholtz instability, and the physics behind it was worked out in the late 1860s. We know this instability explains why wind causes ripples on the surface of water and clouds shear into a row of curves.
For decades scientists argued the same thing must be happening with plasma on the surface of the Sun, and yet nobody had been able to confirm it. Now, a team led by David Kuridze and Friedrich Wöger of the National Solar Observatory reports that Kelvin-Helmholtz instabilities are not just visible on the Sun, but they’re ubiquitous. Their new study proposes that this may change the way we think about how heat, mass, and magnetic energy move through the Sun’s atmosphere.
Telescope’s test drive
The reason plasma whirlpools on the Sun stayed hidden for so long is rather trivial: they are very small. Their scale sits below what telescopes with mirrors smaller than 2 meters can resolve. For most of the history of solar physics, that has ruled out every telescope on Earth. This changed when the US National Science Foundation opened the Daniel K. Inouye Solar Telescope, a 4-meter instrument in Hawaii and the largest solar telescope in the world. The telescope entered its operational phase back in November 2021.
During a three-minute window on April 14, 2025, Kuridze’s team pointed it at an active region near the center of the solar disk and recorded images at a wavelength of 416 nanometers using a diagnostic camera setup built jointly by the National Solar Observatory and the Max Planck Institute for Solar System Research. They were not looking for vortexes, though. “The main goal was to achieve diffraction-limited performance with the telescope,” Kuridze says.