The magnetic structure of Jupiter's magnetopause, as observed by the space probes Pioneer 10 and 11, is compared with terrestrial magnetopause structures from the ogo 5 emission. The Jovian magnetopause thickness, deduced from a rapid triple crossing, is found to lie in the range 3500--5200 km, while the adjoining plasma boundary layer was 5600--8400 km thick. Comparison with the terrestrial situation suggests that the dayside magnetopause thickness in both cases is a few times the ion gyroradius and that the dayside boundary layer is also of about the same width. The magnetopause normal vector and normal magnetic field component are determined for each crossing by use of minimum variance analysis. The results indicate a blunt and floppy mangetopause surface, for the most part with an insignificant normal magnetic field component. Only for three of the 14 crossings did this component exeed 1.5 times its error estimate. In two of these casess, the magnetic field tangential to the magnetopause displayed the characteristic features of a rotational discontinuity. Such structures are occasionally also seen at the earth's magnetopause and are presumably associated with an open (reconnecting) magnetosphere. Some of the Jovian crossings also display other features that have been observed at the earth: initial field rotation in the 'wrong' sense at the outer edge of the magnetopause; diamagnetic effects and field-aligned currents at the inner edge of the plasma boundary layer.