However, there’s a catch. Before electrons can be accelerated by these shock waves, they need to contain a certain amount of energy to begin with. Nobody knows how electrons gain this initial energy.

During this event, electrons in Earth's foreshock region -- an area where the solar wind is predisturbed by its interaction with the bow shock -- reached unprecedented energy levels, surpassing ...

It also sent a supersonic shockwave around the planet, known as a bow shock. New research, published in Geophysical Research Letters, has investigated the effects of this reduced solar wind activity.