  The nuclear interactions of atomic and low energy antiprotons are studied.
Measurements of level shifts and widths in the lightest elements are analyzed
and compared with new results obtained in heavy nuclei. Simple geometric
properties of antiproton - nucleus interactions are demonstrated. Upon this
background one finds some anomalies that indicate strong energy dependence in
the subthreshold antiproton - nucleon interactions. The use of of antiproton in
studies of the nuclear surface is briefly discussed.
