A possible explanation for the anomalous acceleration of Pioneer 10

Abstract

The reported anomalous acceleration of the Pioneer 10 spacecraft of -8.5X10^{-10} m/s^2 (i.e. towards the sun) can be explained by a gravitational interaction on the S-band signals traveling between Pioneer 10 and the earth. The effect of this gravitational interaction is a frequency shift that is proportional to the distance and the square root of the density of the medium in which it travels. If changes in this frequency are interpreted as a Doppler shift the result is an apparent acceleration directed towards the sun. The gravitational interaction is caused by the focusing of the signal photons in curved space where in this case the curvature is related by the density of the interplanetary dust.