Distant bow shock observations by Explorer 33

Abstract

Locations, orientations and magnetic field changes are given for 135 bow shock crossings at distances downstream from earth between 84 and 117 earth radii. The shock locations bracket those calculated for the hypersonic analogue by Dryer and Heckman (1967) for a Mach number of 3.8. The shock normal vectors have been calculated using magnetic coplanarity. The average normal vectors have a greater inclination by about 17 plus or minus 5 deg from the symmetry axis than the Dryer and Heckman shock orientations for a 3.8 Mach number. Over a range of downstream distances from 60 to 115 earth radii, the median magnetic field magnitude jump across the shock changes from 1.90 to 1.70 times.