Remark on ``Indication, from Pioneer 10/11, Galileo, and Ulysses Data,   of an Apparent Anomalous, Weak, Long-Range Acceleration''
  Recently, Anderson et al. presented possible evidence for an anomalous acceleration acting on spacecrafts. Furthermore, the motions of several planets and comets are known to experience unexplained disturbances. A transneptunian comet or asteroid belt might be the common origin of these anomalies. 
R. W. Kuhne