On October 8, 2026, ESA reports that Solar Orbiter’s readings of charged oxygen and carbon particles point to hot magnetic loops at the Sun as the origin of one studied solar-wind switchback. The particle mix also indicates interchange reconnection as the feature’s formation process.
What is a solar-wind switchback?
The solar wind is plasma flowing outward from the Sun. A switchback is an S-shaped kink in the magnetic field carried by that flow. In an earlier observation in 2022, Solar Orbiter confirmed the S shape of a switchback; the finding reported today traces a studied feature’s likely solar origin.
Particles point to hot magnetic loops
Solar Orbiter flew through a very large switchback and used its Solar Wind Analyser (SWA) to sample the plasma inside it. ESA says the spacecraft was roughly halfway between Earth and the Sun during the sampling.
The mix of charged oxygen and carbon particles carried fingerprints that point to hot magnetic loops at the Sun’s surface. ESA reports that researchers interpret this composition as evidence for interchange reconnection, a process involving open and closed magnetic regions.
Reconnection forms it; waves shape its later motion
Open magnetic regions have field lines that extend into space. Closed magnetic loops can hold plasma. During interchange reconnection, the magnetic connections change, allowing plasma trapped in a loop to escape. ESA says the particle mix points to this process in the formation of the studied switchback.
Waves and turbulence have a later role: they likely influence the switchback’s motion after it leaves the Sun. The account places these processes at different stages—reconnection in formation, then waves and turbulence during the feature’s journey through space.
How the solar source was traced
The analysis brought together particle observations made in space, images of the Sun’s disc and magnetic-field modeling. ESA says a model linked Solar Orbiter measurements with data from NASA Solar Dynamics Observatory to identify the plasma’s solar source.
That combination connects the particle composition measured within the switchback to magnetic structures at the Sun. ESA identifies the associated study, “On the Coronal Origin of Magnetic Switchbacks in the Solar Wind,” as published in Nature Astronomy on October 8, 2026.
