English

A flyby anomaly for Juno? Not from standard physics

General Relativity and Quantum Cosmology 2014-11-10 v2 Earth and Planetary Astrophysics Space Physics

Abstract

An empirical formula recently appeared in the literature to explain the observed anomalies of about Δρ˙110\Delta\dot\rho\approx 1-10 mm s1^{-1} in the geocentric range-rates ρ˙\dot\rho of the Galileo, NEAR and Rosetta spacecraft at some of their past perigee passages along unbound, hyperbolic trajectories. It predicts an anomaly of the order of 66 mm s1^{-1} for the recent flyby of Juno, occurred on 9 October 2013. Data analyses to confirm or disproof it are currently ongoing. We numerically calculate the impact on the geocentric Juno's range rate of some classical and general relativistic dynamical effects which are either unmodelled or mismodelled to a certain level in the software used to process the data. They are: a) The first even zonal harmonic coefficient J2J_2 of the multipolar expansion of the terrestrial gravitational potential causing orbital perturbations both at the a)\left.{\rm a}^{'}\right) Newtonian (J2J_2) and at the a)\left. {\rm a}^{''}\right) first post-Newtonian level (J2c2J_2 c^{-2}) b) The post-Newtonian gravitoelectric (GE) Schwarschild-like component of the Earth's gravitational field c) The post-Newtonian gravitomagnetic (GM) Lense-Thirring effect. The magnitudes of their mismodeled and nominal range-rate signatures are: a)\left. {\rm a}^{'}\right) Δρ˙σJ21\Delta\dot\rho_{\sigma_{J_2}} \approx 1 μ\mum s1^{-1} a)\left. {\rm a}^{''}\right) Δρ˙J2c20.015\Delta\dot\rho_{J_2 c^{-2}} \approx 0.015 μ\mum s1^{-1} b) Δρ˙GE25\Delta\dot\rho_{\rm GE} \approx 25 μ\mum s1^{-1} c) Δρ˙GM0.05\Delta\dot\rho_{\rm GM} \approx 0.05 μ\mum s1^{-1}. If a flyby anomaly as large as a few mm s1^{-1} will be finally found also for Juno, it will not be due to any of these standard gravitational effects. (Abridged)

Keywords

Cite

@article{arxiv.1311.4218,
  title  = {A flyby anomaly for Juno? Not from standard physics},
  author = {Lorenzo Iorio},
  journal= {arXiv preprint arXiv:1311.4218},
  year   = {2014}
}

Comments

LaTex2e, 1 figure, no tables, 67 references. Accepted for publication in Advances in Space Research

R2 v1 2026-06-22T02:09:10.178Z