* The anomalous acceleration could be due to the spacecraft venting energy in certain directions.<ref>http://www.symmetrymagazine.org/breaking/2008/04/13/pioneer-spacecraft-a-step-closer-to-being-boring/</ref> However, such effects would be expected to be more significant earlier on, when the power sources were less degraded.<ref name="Nieto" /> The opposite was actually the case. | * The anomalous acceleration could be due to the spacecraft venting energy in certain directions.<ref>http://www.symmetrymagazine.org/breaking/2008/04/13/pioneer-spacecraft-a-step-closer-to-being-boring/</ref> However, such effects would be expected to be more significant earlier on, when the power sources were less degraded.<ref name="Nieto" /> The opposite was actually the case. |