Related papers: Chameleon effect and the Pioneer anomaly
We work out the impact that the recently determined time-dependent component of the Pioneer Anomaly (PA), interpreted as an additional exotic acceleration of gravitational origin with respect to the well known PA-like constant one, may have…
Our previous analyses of radio Doppler and ranging data from distant spacecraft in the solar system indicated that an apparent anomalous acceleration is acting on Pioneer 10 and 11, with a magnitude a_P ~ 8 x 10^{-8} cm/s^2, directed…
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…
Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude $\sim 8.5\times 10^{-8}$ cm/s$^2$, directed towards the Sun. Two…
In addition to its long-term constancy, the Pioneer (spacecraft) anomaly appears to only exist for bodies whose mass is less than that of: planets, moons, comets, and heavy asteroids of known mass. Assuming the observational evidence is…
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…
The unexplained sunward acceleration $a_\mathrm{P}$ of the Pioneer 10 (P10) and the Pioneer 11 (P11) spacecraft remains a mystery. A scalar potential model (SPM) that derived from considerations of galaxy clusters, of redshift, and of…
Analysis of radio-metric tracking data from the Pioneer 10/11 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…
In this paper we analyze the impact on the orbital motions of the outer planets of the solar system from Jupiter to Pluto of some velocity-dependent forces recently proposed to phenomenologically explain the Pioneer anomaly, and compare…
It is shown that the same phenomenological Newtonian model recently proposed by the author to explain the cosmological evolution of the fine structure constant suggests furthermore an explanation of the unmodelled acceleration $a_P\simeq…
Recently we reported that radio Doppler data generated by NASA's Deep Space Network (DSN) from the Pioneer 10 and 11 spacecraft indicate an apparent anomalous, constant, spacecraft acceleration with a magnitude $\sim 8.5\times 10^{-8}$ cm…
The Pioneer 10 and 11 spacecraft yielded very accurate navigation that was limited only by a small, anomalous frequency drift of their carrier signals received by the NASA Deep Space Network (DSN). This discrepancy, evident in the data for…
We review the fundamental results of a new cosmological model, based on conformal gravity, and apply them to the analysis of the early data of the Pioneer anomaly. We show that our conformal cosmology can naturally explain the anomalous…
We present a methodology based on point-like Lambertian sources that enables one to perform a reliable and comprehensive estimate of the overall thermally induced acceleration of the Pioneer 10 and 11 spacecraft. We show, by developing a…
We discuss astronomical and astrophysical evidence, which we relate to the principle of zero-total energy of the Universe, that imply several relations among the mass M, the radius R and the angular momentum L of a "large" sphere…
It is proposed that the recently reported anomalous acceleration acting on the Pioneers spacecrafts should be a consequence of the existence of some local curvature in light geodesics when using the coordinate speed of light in an expanding…
A method for the computation of the radiative momentum transfer in the Pioneer 10 & 11 spacecraft due to the diffusive and specular components of reflection is presented. The method provides a reliable estimate of the thermal contribution…
We review some of the properties of chameleon theories. Chameleon fields are gravitationally coupled to matter and evade gravitational tests thanks to two fundamental properties. The first one is the density dependence of the chameleon…
Pioneer 10 and 11 were the first probes sent to study the outer planets of the Solar System and Pioneer 10 was the first spacecraft to leave the Solar System. Besides their already epic journeys, Pioneer 10 and 11 spacecraft were subjected…
The reported anomalous acceleration acting on the Pioneers spacecrafts could be seen as a consequence of the existence of some local curvature in light geodesics when using the coordinate speed of light in an expanding space-time. The…