Because of Earth’s magnetic field, the stream of electrons and ions that constantly blows from the Sun gets diverted around the planet. The particles mostly travel with the solar-wind magnetic field lines on their way past Earth, but sometimes they breach the magnetosphere, the region of space where the dominant magnetic field is that of Earth. Such breaches eventually manifest themselves as auroras and geomagnetic storms. Driving the large-scale bursts of energy released in those space weather events are electron interactions that may be an important mechanism for energy conversion throughout the solar system.
When oppositely directed magnetic field lines approach each other in astrophysical plasmas, they can break and reconnect in a lower-energy configuration (see the article by Forrest Mozer and Philip Pritchett, Physics Today, June 2010, page 34). Bent tightly at first, the field lines abruptly straighten, which sends charged particles streaming away from the reconnection...
