Narrow Results

Results from an almost twenty years study of radiometric data from Pioneer 10/11, Galileo and Ulysses spacecraft indicate an anomalous time depending blueshift^{1, 2} which bares hardly prosaic explanations. Local manifestation of the expansion of the universe or new force terms are not favored either by the observational data. So, we explore the possibility that the reported anomaly, referred to as the "Pioneer anomaly", does not result from a real change in velocity. It turns out that the main Pioneer anomaly may be looked at as a new validation of general relativity (GR) in the weak field and low velocity limit on account of the "machian" behavior of quintessence like dark energy.