general relativity - The Pioneer anomaly finally explained?

Pioneer 10 & 11 are robotic space probes launched by the NASA in the early 1970's. After leaving our solar system, an unusual deceleration of both spacecrafts has been measured to be approximately $$\ddot{r}_p = -(8.74±1.33)×10^{−10} \frac{m}{s^2}$$ with respect to our solar system.

Several attempts were made to explain this tiny effect, called the Pioneer anomaly, but none was fully accepted in the scientific community so far.

Two months ago, Frederico Francisco et al have proposed another solution to the problem. They assume, roughly speaking, that the thermal radiation of the spacecraft caused by plutonium on board along with the actual structure of the probes is responsible for this mystery of modern physics.

Here an image of Pioneer 10 taken from Wikipedia along with a sketch of the radiation model employed in the paper:

Hence my question:

Is the Pioneer anomaly finally explained?

Sincerely

Answer

I'll stick my neck out and say that the answer to your question is simply "yes."

First off, these detailed thermal models are complex and hard to do, so we want confirmation from independent groups. We have that: Rievers and Lämmerzahl, "High precision thermal modeling of complex systems with application to the flyby and Pioneer anomaly," gr-qc/1104.3985

Second, we could ask whether these results contradict previous work. The answer is basically no. Previous work was simply sloppy. There is a nice talk on this topic here by Toth: http://streamer.perimeterinstitute.ca/Flash/a2cc528b-1d36-4a2e-af73-5f81b8b17477/viewer.html There is a long history where people did back-of-the-envelope estimates of the thermal effects and said, "Look, the order of magnitude is too small to matter!" It just turns out that the back-of-the-envelope were wrong.

Finally, all of this stuff is very tough to be sure of, because there are so many uncertainties about things like the degradation of the white paint on the RTGs. Therefore it would be good to have independent ways of testing the hypothesis of a gravitational anomaly, without having to use the Pioneer data at all. We do have these independent tests. If the effect obeyed the equivalence principle, it would have had effects on the outer solar system that are not in fact observed: Iorio, "Does the Neptunian system of satellites challenge a gravitational origin for the Pioneer anomaly?," gr-qc/0912.2947

It's dead, Jim.