Apsidal precession of the outer solar planetary orbits due to the pioneer anomaly

Abstract

Despite the now common position that the Pioneer anomaly is not a real gravitational effect but an effect due to the on-board thermal recoil forces – for curiosity’s sake, we here take the suggestion of Nyambuya (2015) where it has been assumed that the Pioneer anomaly – can, in-principle, be attributed to a gravitational effect due to these spacecrafts accreting some material from a rarefied Interplanetary Medium (IPM) in the domain where the Pioneer anomaly has manifested [20 AU ≲ r ≲ 70 AU]. If this assumption is correct, then, the expected Pioneer acceleration of these spacecrafts maybe much smaller than the Pioneer acceleration to cause as noticeable apsidal precession of the outer Solar planets Uranus, Neptune and Pluto, thus making it difficult to rule-out a gravitational origin of the Pioneer anomaly.