  Within the dark matter paradigm, explaining observed orbital dynamics at
galactic level through the inclusion of a dominant dark halo, implies also the
necessary appearance of dynamical friction effects. Satellite galaxies,
globular clusters and even stars orbiting within these galactic halos, will
perturb the equilibrium orbits of dark matter particles encountered, to produce
a resulting trailing wake of slightly enhanced dark matter density associated
with any perturber in the halo. The principal effect of this gravitational
interaction between an orbiting body and the dark matter particles composing
it, is the appearance of a frictional drag force slowly removing energy and
angular momentum from the perturber. Whilst this effect might be relevant to
help bring about the actual merger of the components of interacting forming
galaxies, at smaller stellar scales, it becomes negligible. However, the
trailing wake will still be present. In this letter I show that the
corresponding dark matter wake associated to the Sun, will constitute a small
but resonant perturbation on solar system dynamics which can be ruled out, as
current laser and radio ranging measurements are now over an order of magnitude
more precise than the amplitude of the orbital perturbations which said wake
implies. The absence of any such detection implies the nonexistence of the
dynamical friction trailing wake on the sun, which in turn strongly disfavours
dark matter as an explanation for the observed gravitational anomalies at
galactic scales.
