Sunday, March 20, 2005

New Scientist got it wrong on direction of Pioneer Anomaly

Yes, so I had it correct, Nature had it correct, but New Scientist has it wrong in their latest issue on 13 things that don't make sense.

On Mar 19, 2005, at 10:36 PM, Gary S Bekkum / SSR wrote:

Study of the Pioneer Anomaly: A Problem Set

http://www.arxiv.org/abs/physics/0502123

Analysis of the radio-metric tracking data from the Pioneer 10 and
11 spacecraft at distances between 20--70 astronomical units (AU) from
the Sun has consistently indicated the presence of an anomalous,
small, constant Doppler frequency drift. The drift is a blue-shift,
uniformly changing at the rate $\dot{\nu} \sim (5.99 \pm 0.01) \times 10^{-9}$ Hz/s. The signal also can be interpreted as a constant
acceleration of $a_P = (8.74 \pm 1.33) \times 10^{-8}$ cm/s$^2$
directed towards the Sun. This interpretation has become known as the
Pioneer anomaly.
The nature of this anomaly remains unexplained. That is to say, up
to now no unambiguous explanation of the anomalous signal has been
found. To reach this conclusion a complicated interplay between
experiment and theory is needed to rule out systematics. However, in
the end many of the necessary calculations are amenable to students.
To elucidate this students would have a deeper understanding of the
workings of physics in space systems. We give a problem set devoted to
this cause.