https://phys.org/news/2018-05-earth-solar-gentle-breeze.html

A University of Maryland-led study describes the first observations of the process of electron heating in Earth's bow shock. The researchers found that when the electrons in the solar wind encounter the bow shock, they momentarily accelerate to such a high speed that the electron stream becomes unstable and breaks down. This breakdown process robs the electrons of their high speed and converts the energy to heat.

The results add an important new dimension to scientists' understanding of Earth's magnetic field and its ability to protect the planet from harmful particles and radiation. The research paper was published in the journal Physical Review Letters on May 31, 2018.