Solar Orbiter traces a magnetic switchback back to the Sun

Solar Orbiter has passed through a large kink in the solar wind’s magnetic field, allowing researchers to trace the material inside it back to the Sun, the European Space Agency says. The finding offers a clue to how these magnetic ‘switchbacks’ begin, a question scientists have debated. [1]

The spacecraft was roughly halfway between Earth and the Sun when its Solar Wind Analyser sampled the plasma in the switchback. Researchers found a mix of charged oxygen and carbon particles that they say points to hot magnetic-field loops at the Sun. Lead author Jesse Coburn interprets the mix as evidence for ‘interchange reconnection’: a process in which magnetic fields reconnect, allowing plasma trapped in a loop to escape into space. [1]

To locate the solar source, the team combined those particle measurements with images of the Sun, magnetic-field modelling and data from NASA’s Solar Dynamics Observatory. The analysis concerns one switchback, rather than establishing that every switchback forms in the same way. [1]