The Quest to Understand the Pioneer Anomaly

We show that the anomalous acceleration of the Pioneer 10/11 spacecraft can be explained if there is some mirror gas or mirror dust in our solar system.

In this paper we investigate the effects that an anomalous acceleration as that experienced by the Pioneer spacecraft after they passed the 20 AU threshold would induce on the orbital motions of the Solar System planets placed at heliocentric distances of 20 AU or larger as Uranus, Neptune and Pluto. It turns out that such an acceleration, with a magnitude of 8.74\times 10^-10 m s^-2, would affect their orbits with secular and short-period signals large enough to be detected ...

This paper proposes an explanation for the Pioneer anomaly: an unexplained Sunward acceleration of 8.74 +/- 1.33 x 10^-10 m s^-2 seen in the behaviour of the Pioneer probes. Two hypotheses are made: (1) Inertia is a reaction to Unruh radiation and (2) this reaction is weaker for low accelerations because some wavelengths in the Unruh spectrum do not fit within a limiting scale (twice the Hubble distance) and are disallowed: a process similar to the Casimir effect. When these ...

The reported anomalous acceleration may be explained as the recoil of radiated waste RTG heat scattered by the back of the high gain antenna.

Anderson, et al., find the measured trajectories of Pioneer 10 and 11 spacecraft deviate from the trajectories computed from known forces acting on them. This unmodelled acceleration can be accounted for by non-isotropic radiation of spacecraft heat. This explanation was first proposed by Murphy, but Anderson, et al. felt it could not explain the observed effect. This paper includes new calculations on the expected magnitude of this effect, based on the relative emissivities ...

Analysis of the radio tracking data from the Pioneer 10/11 spacecraft at distances between about 20 - 70 AU from the Sun has indicated the presence of an unmodeled, small, constant, Doppler blue shift which can be interpreted as a constant acceleration of a_P= (8.74 \pm 1.33) \times 10^{-8} cm/s^2 directed approximately towards the Sun. In addition, there is early (roughly modeled) data from as close in as 5 AU which indicates there may have been an onset of the anomaly near ...

Precision navigation of spacecraft requires accurate knowledge of small forces, including the recoil force due to anisotropies of thermal radiation emitted by spacecraft systems. We develop a formalism to derive the thermal recoil force from the basic principles of radiative heat exchange and energy-momentum conservation. The thermal power emitted by the spacecraft can be computed from engineering data obtained from flight telemetry, which yields a practical approach to incor...

We propose here an explanation of the Pioneer anomaly which is not in conflict with the cartography of the solar system. In our model, the spaceship does not suffer any extra acceleration but follows the trajectory predicted by standard gravitational theory. The observed acceleration is not real but apparent and has the same observational footprint as a deceleration of astronomical time with respect to atomic time. The details can be summarized as follows: i) as we argued in ...

We present source code for the computer algebra system Mathematica that analyzes the motion of the Pioneer spacecraft using the public available ephemeris data from JPL's website. Within 15 minutes, the reader can verify that the Pioneer anomalous acceleration a_p (1) exists in the order of magnitude of c H_0, (2) is not due to mismodeling of gravitational attraction, solar pressure or spacecraft attitude maneuvers. The simple code of about 100 lines may easily be extended by...

The anomalous acceleration of Pioneer 10 and 11 spacecraft of (8.74 \pm 1.33) \times 10^{-8} cm. s^{-2} fits with a theoretical prediction of a minimal acceleration in nature of about 7.61 \times 10^{-8} cm. s^{-2}