Increase of the mean Sun-Earth distance caused by a secular mass accumulation

Based on many planetary observations between the years 1971 and 2003, Krasinsky and Brumberg (Celest. Mech. Dyn. Astron. 90:267-288, 2004) have estimated a rate of increase in the mean Sun-Earth distance of (15 +/- 4) m per century. Together with other anomalous observations in the solar system, this increase appears to be unexplained (Lammerzahl et al. in Astrophys. Space Sci. Lib., vol. 349, pp. 75-101, 2008). We explain these findings by invoking a recently proposed gravitational impact model (Wilhelm et al. in Astrophys. Space Sci. 343:135-144, 2013) that implies a secular mass increase of all massive bodies. This allows us to formulate a quantitative understanding of the effect within the parameter range of the model with a mass accumulation rate of the Sun of (6.4 +/- 1.7)x10(10) kg s(-1).