A new analysis of magnetic and concurrent plasma data collected from the space probes Pionecr 5, Explorer 10, and Mariner 2 yields a new model of the interplanetary magnetic field. It is hypothesized that the observed interplanetary field F/sub i/ is due to motion of the magnetometer relative to a negatively charged rotating sun from which magnetic lines of force are drawn out into space by a flow of plasma clouds and from which solar disturbances are propagated as generalized magneto-ionic waves. Application of the hypothesis is made to facts gathered from the space probes. It is proposed that future space probes carry devices that can determine the concentration of the protons and electrons separately, or else the concentration of the protons and of the excess charges per unit volume of plasma, and a device for measuring ambient electrostatic fields ranging from 10 to 1000 v/cm. (H.M.G.)