Pioner Anomaly shows up in other spacecraft

The anomalous change in velocity (tiny though it may be) detected in tracking the Pioneer 10 and 11 spacecraft is no longer an isolated event. A study of six other space probes has revealed anomalies in the velocity of five of them.
JPL astronomer John Anderson, who discovered the Pioneer anomaly, says, "I am feeling both humble and perplexed by this. There is something very strange going on with spacecraft motions. We have no convincing explanation for either the Pioneer anomaly or the flyby anomaly."
I believe it was Haldane who said the universe was not only stranger than we imagined, but stranger than we could imagine....