Bow Shock

The bow shock is a shock wave formed at a distance of 3-4 Earth radii or so in front of the nose of the magnetopause by the encounter of the supersonic solar wind with the “obstacle” to its flow presented by the Earth’s magnetic field. The bow shock is so named by analogy to the wave formed by the bow of a ship as it passes through water. Unlike the shock wave that precedes an airplane flying at supersonic speeds, the bow shock is a stationary (i.e., non-propagating) shock. The bow shock occurs in a medium–the solar wind.