Ephemeris Reconstruction for Comet 67P/Churyumov-Gerasimenko During Rosetta Proximity Phase from Radiometric Data Analysis

Fuente: arXiv
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Main Authors: Manghi, Riccardo Lasagni, Zannoni, Marco, Tortora, Paolo, Budnik, Frank, Godard, Bernard, Attree, Nicholas
Format: Preprint
Published: 2024
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author Manghi, Riccardo Lasagni
Zannoni, Marco
Tortora, Paolo
Budnik, Frank
Godard, Bernard
Attree, Nicholas
author_facet Manghi, Riccardo Lasagni
Zannoni, Marco
Tortora, Paolo
Budnik, Frank
Godard, Bernard
Attree, Nicholas
contents This study provides a continuous ephemeris reconstruction for comet 67P/Churyumov-Gerasimenko by reanalyzing Rosetta radiometric measurements and Earth-based astrometry. Given the comet-to-spacecraft relative trajectory provided by the navigation team, these measurements were used to estimate the comet state and some critical physical parameters, most notably the non-gravitational accelerations induced by the outgassing of surface volatiles, for which different models were tested and compared. The reference reconstructed ephemeris, which uses a stochastic acceleration model, has position uncertainties below 10 km, 30 km, and 80 km in the orbital radial, tangential, and normal directions for the whole duration of the Rosetta proximity phase (from July 2014 to October 2016). Furthermore, the solution can fit ground-based astrometry between March 2010 and July 2018, covering a complete heliocentric orbit of 67P. The estimated comet non-gravitational accelerations are dominated by the orbital radial and normal components, reaching peak values of $(1.28 \pm 0.17) \times 10^{-8} \, \text{m/s}^2$ and $(0.52 \pm 0.20) \times 10^{-8} \, \text{m/s}^2$, respectively 15 days and 24 days after perihelion. Furthermore, the acceleration magnitude is shown to have a steep dependence on the comet heliocentric distance $\text{NGA} \sim r_\odot^{-6}$ and shows asymmetries in the pre- and post-perihelion activities. The estimated acceleration components, agnostic due to the limited physical assumptions, could be used as a constraint for future investigations involving high-fidelity thermophysical models of the comet surface.
format Preprint
id arxiv_https___arxiv_org_abs_2407_17615
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ephemeris Reconstruction for Comet 67P/Churyumov-Gerasimenko During Rosetta Proximity Phase from Radiometric Data Analysis
Manghi, Riccardo Lasagni
Zannoni, Marco
Tortora, Paolo
Budnik, Frank
Godard, Bernard
Attree, Nicholas
Earth and Planetary Astrophysics
This study provides a continuous ephemeris reconstruction for comet 67P/Churyumov-Gerasimenko by reanalyzing Rosetta radiometric measurements and Earth-based astrometry. Given the comet-to-spacecraft relative trajectory provided by the navigation team, these measurements were used to estimate the comet state and some critical physical parameters, most notably the non-gravitational accelerations induced by the outgassing of surface volatiles, for which different models were tested and compared. The reference reconstructed ephemeris, which uses a stochastic acceleration model, has position uncertainties below 10 km, 30 km, and 80 km in the orbital radial, tangential, and normal directions for the whole duration of the Rosetta proximity phase (from July 2014 to October 2016). Furthermore, the solution can fit ground-based astrometry between March 2010 and July 2018, covering a complete heliocentric orbit of 67P. The estimated comet non-gravitational accelerations are dominated by the orbital radial and normal components, reaching peak values of $(1.28 \pm 0.17) \times 10^{-8} \, \text{m/s}^2$ and $(0.52 \pm 0.20) \times 10^{-8} \, \text{m/s}^2$, respectively 15 days and 24 days after perihelion. Furthermore, the acceleration magnitude is shown to have a steep dependence on the comet heliocentric distance $\text{NGA} \sim r_\odot^{-6}$ and shows asymmetries in the pre- and post-perihelion activities. The estimated acceleration components, agnostic due to the limited physical assumptions, could be used as a constraint for future investigations involving high-fidelity thermophysical models of the comet surface.
title Ephemeris Reconstruction for Comet 67P/Churyumov-Gerasimenko During Rosetta Proximity Phase from Radiometric Data Analysis
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2407.17615