Laboratory experiments have been performed that show the effects of inserting a spherical conducting model, large in comparison with the Debye lenght, into a free streaming high-energy (1 kV) unmagnetized hydrogen plasma. These experiments are the first laboratory measurements at energies and compositions directly relevant to solar wind and astrophysical plasma phenomena. The incident plasma parameters were held constant. Transverse profiles of the net Langmuir probe current, plotted at various locations downstream in the model wake, are divided into three regions-the 'shadow,' the 'transition,' and the 'boundary.' The following new results are obtained: (1) enhancements in the 'shadow' exist at downstream locations where the Mach ratio is less than one: (2) turbulence exists in the 'transition' region on the shadow edges and outside in the 'boundary' region. These results appear to be attributable to the use of a high-energy plasma for these studies. A small current enhancement is also present in the boundary and is attributable to the plasma/model interaction, in close agreement with low-energy plasma/model interaction experiments. We speculate the many similar features observed by in situ spacecraft downstream from planetary bodies are relatively permanent and are due to the intrinsic nature of the interaction between the solar wind plasma and the obstacle rather than to transitory effects caused by the presence of discontinuities or other transitory characteristics associated with the flow.