Solar Orbiter Links Solar Wind Switchback to Sun's Surface

The European Space Agency-led Solar Orbiter flew through a switchback in the solar wind and confirmed its S shape. Researchers traced the feature to its origin on the Sun's surface. ESA announced the result in 2022.

Solar Orbiter, a mission led by the European Space Agency, identified a bend in the solar wind's magnetic field and then crossed a switchback confirmed to be S-shaped. Such features are frequently observed close to the Sun.

The spacecraft was positioned about halfway between Earth and the Sun. Its analysis combined in-situ measurements from the Solar Wind Analyser, images of the solar disc, and modelled magnetic fields.

Solar Orbiter sampled rarely observed particles carrying signs of their origin. Jesse and colleagues identified charged oxygen and carbon particles, which formed inside hot magnetic field loops at the Sun's surface.

The particle mix was identified as strong evidence for interchange reconnection. That process happens when solar regions with different magnetic properties interact. In open regions, magnetic field lines extend outward, while closed regions contain lines that curve back toward the Sun.

The mission also found that waves are important in heating and speeding up the solar wind. Within the switchback, evidence of waves and turbulence likely appeared mainly after the structure moved outward, with waves and turbulence taking over once it left the Sun. Both interchange reconnection and waves or turbulence are involved.

Jesse Coburn is affiliated with CNRS/LPP in France, and Stephanie Yardley with Northumbria University in the UK. The solar wind flows continuously from the Sun into space, while the Sun's intense and restless magnetic field can make field lines twist, snap, or fold back. This produces dynamic activity in the solar wind.

For lunar-industry readers, the facts contain no Moon-related detail. Their relevance is that they describe an ESA-led Solar Orbiter observation linking a switchback to magnetic processes on the Sun and to waves and turbulence in the continuously outward-flowing solar wind.