  The dominant contributions from a discrete gravitational interaction produce
the standard potential as an effective continuous field. The sub-dominant
contributions are, in a first approximation, linear on n, the accumulated
number of (discrete) interaction events along the test-body trajectory. For a
nearly radial trajectory n is proportional to the traversed distance and its
effects may have been observed as the Pioneer anomalous constant radial
acceleration, which cannot be observed on the nearly circular planetary orbits.
