  Both the recently reported anomalous secular increase of the astronomical
unit, of the order of a few cm yr^-1, and of the eccentricity of the lunar
orbit e_ = (9+/-3) 10^-12 yr^-1 can be phenomenologically explained by
postulating that the acceleration of a test particle orbiting a central body,
in addition to usual Newtonian component, contains a small additional radial
term proportional to the radial projection vr of the velocity of the particle's
orbital motion. Indeed, it induces secular variations of both the semi-major
axis a and the eccentricity e of the test particle's orbit. In the case of the
Earth and the Moon, they numerically agree rather well with the measured
anomalies if one takes the numerical value of the coefficient of
proportionality of the extra-acceleration approximately equal to that of the
Hubble parameter H0 = 7.3 10^-11 yr^-1.
