Scientists get a new clue to the origin of solar wind 'switchbacks'

Scientists have obtained a new insight into the origin of solar wind switchbacks, thanks to data collected by the European Space Agency's Solar Orbiter. Switchbacks are S-shaped kinks in the solar wind's magnetic field, marked by sudden and large deflections. Initially thought to originate near the Sun's surface, a recent flight through a switchback has identified its source as hot magnetic loops at the Sun's surface.

Using the Solar Wind Analyser instrument, Solar Orbiter sampled particles in the switchback that could only have formed within these magnetic loops, providing a smoking gun for a specific formation process. The particles detected are consistent with interchange reconnection, a phenomenon that occurs when parts of the Sun with different magnetic properties interact.

While another theory involving waves and turbulence also plays a role after the switchback leaves the Sun, the new findings reveal the switchback's solar source and offer valuable insights into the Sun's heating process and the acceleration of solar wind particles into space. This information has implications for predicting solar storms and their severity, ultimately helping to protect Earth and space-based infrastructure from extreme space weather events.