scholarly journals A Study of the Errors in Swing-by Design by the "Patched-Conics" Approach Applied to the Galilean Moons

2017 ◽  
Author(s):  
Antonio Fernando Bertachini A. Prado
Keyword(s):  
Galilean Moons ◽  
Patched Conics

Ground-based observations of the [SII] 6731 Å emission lines of the Io plasma torus

2016 ◽  
Vol 12 (S328) ◽  
pp. 227-229
Author(s):  
P. Magalhães Fabíola ◽  
Walter Gonzalez ◽  
Ezequiel Echer ◽  
Mariza P. Souza-Echer ◽  
Rosaly Lopes ◽  
...  
Keyword(s):  
Charged Particles ◽  
Emission Lines ◽  
Solar Telescope ◽  
The Moon ◽  
Active Object ◽  
Oxygen Ions ◽  
Galilean Moons ◽  
Plasma Torus ◽  
Io Plasma Torus ◽  
Galilean Moons Of Jupiter

AbstractThe Io Plasma Torus (IPT) is a doughnut-shaped structure of charged particles, composed mainly of sulfur and oxygen ions. The main source of the IPT is the moon Io, the most volcanically active object in the Solar System. Io is the innermost of the Galilean moons of Jupiter, the main source of the magnetospheric plasma and responsible for injecting nearly 1 ton/s of ions into Jupiter's magnetosphere. In this work ground-based observations of the [SII] 6731 Å emission lines are observed, obtained at the MacMath-Pierce Solar Telescope. The results shown here were obtained in late 1997 and occurred shortly after a period of important eruptions observed by the Galileo mission (1996-2003). Several outbursts were observed and periods of intense volcanic activity are important to correlate with periods of brightness enhancements observed at the IPT. The time of response between an eruption and enhancement at IPT is still not well understood.

5. Regular satellites in close up

2015 ◽  
pp. 85-114
Author(s):  
David A. Rothery
Keyword(s):  
Space Missions ◽  
Giant Planets ◽  
Extraterrestrial Life ◽  
Galilean Moons ◽  
Future Space ◽  
Physical Features

Regular satellites of the giant planets have been described as ‘worlds in their own right’. ‘Regular satellites in close up’ describes the fascinating physical features and chemistry of Jupiter’s ‘Galilean moons’—Io, Europa, Ganymede, and Callisto—before considering Saturn’s moons, Titan, Enceladus, and Iapetus, as well as Miranda and Ariel, the moons of Uranus, and Triton, a moon of Neptune. These moons have very distinct characteristics and some are widely regarded as better candidates than Mars for hosting extraterrestrial life. It concludes with a look towards future space missions to observe and examine these distant moons.

The Galilean Moons of Jupiter

1980 ◽  
Vol 242 (1) ◽  
pp. 88-100 ◽  
Author(s):  
Laurence A. Soderblom
Keyword(s):  
Galilean Moons ◽  
Galilean Moons Of Jupiter

Cassini state of Galilean Moons: Influence of a subsurface ocean

2020 ◽  
Author(s):  
Alexis Coyette ◽  
Rose-Marie Baland ◽  
Anne Lemaitre ◽  
Tim Van Hoolst
Keyword(s):  
Rotation Axis ◽  
Rigid Bodies ◽  
Galilean Satellites ◽  
Precession Rate ◽  
Subsurface Ocean ◽  
Galilean Moons ◽  
Existence And Stability ◽  
Synchronous Rotation ◽  
Laplace Plane ◽  
Cassini State

<p>Large moons such as the Galilean satellites are thought to be in an equilibrium rotation state, called a Cassini state (Peale, 1969). This state is characterized by a synchronous rotation and a precession rate of the rotation axis that is equal to the precession rate of the normal to its orbit. It also implies that the spin axis, the normal to the orbit and the normal to the Laplace plane are coplanar with a (nearly) constant obliquity.</p><p>For rigid bodies, up to 4 possible Cassini states exist, but not all of them are stable. It is generally assumed that the Galilean satellites are in Cassini State I for which the obliquity is close to zero (see e.g. Baland et al. 2012). However, it is also theoretically possible that these satellites occupy or occupied another Cassini state.</p><p>We here investigate how the interior structure, and in particular the presence of a subsurface ocean, influences the existence and stability of the different possible Cassini states.</p><p><em>References :</em></p><p>Baland, R.M., Yseboodt, M. and Van Hoolst, T. (2012). Obliquity of the Galilean satellites: The influence of a global internal liquid layer. Icarus 220, 435-448.</p><p>Peale, S. (1969). Generalized Cassini’s laws. Astron. J. 74 (3), 483-489.</p>

ExPRES Modeling of Auroral Radio Source Occultation observed by Galileo Application to JUICE and Juno

2020 ◽  
Author(s):  
Baptiste Cecconi ◽  
Corentin K Louis ◽  
Claudio Munoz ◽  
Claire Vallat
Keyword(s):  
Radio Emission ◽  
Radio Source ◽  
Plasma Waves ◽  
Physical Parameters ◽  
Operation Planning ◽  
Radio Emissions ◽  
Galilean Moons ◽  
Temporal Occurrence ◽  
Galilean Moon ◽  
Ionospheric Sounding

<p>The ExPRES code simulates exoplanetary and planetary auroral radio emissions. It could be used to predict and interpret Jupiter’s radio emissions in the hectometric and decametric range. In this study, we model the occultations of the Jovian auroral radio emissions during the Galilean moons flybys by the Galileo spacecraft. In this study, we focus on auroral radio emissions, configuring the ExPRES simulations runs with typical radio source physical parameters. We compare the simulations run results with the actual Galileo/PWS observations, and show that we accurately model the temporal occurrence of the occultations in the whole spectral range observed by Galileo. We can then predict auroral radio emission occultations by the Galilean moons for the Juno and JUICE missions. ExPRES will be used by the JUICE/RPWI (Radio Plasma Waves Investigation) team to prepare its operation planning during the Galilean moon flybys for, e.g., the Galilean moon ionosphere characterization science objective, with passive ionospheric sounding during ingress and egress of Jovian radio source occultations. </p>

scholarly journals An Impacting Descent Probe for Europa and the Other Galilean Moons of Jupiter

2017 ◽  
Vol 120 (2) ◽  
pp. 113-146 ◽  
Author(s):  
P. Wurz ◽  
D. Lasi ◽  
N. Thomas ◽  
D. Piazza ◽  
A. Galli ◽  
...  
Keyword(s):  
The Other ◽  
Galilean Moons ◽  
Galilean Moons Of Jupiter

Galileo Explores the Galilean Moons

Science News ◽  
1997 ◽  
Vol 152 (6) ◽  
pp. 90
Author(s):  
Ron Cowen
Keyword(s):  
Galilean Moons

scholarly journals Europa’s interaction with the jovian plasma from hybrid simulation

2021 ◽  
Author(s):  
Claire-Alexandra Baskevitch ◽  
Baptiste Cecconi ◽  
Ronan Modolo
Keyword(s):  
Ray Tracing ◽  
Radio Waves ◽  
Planetary Environments ◽  
Galilean Moons ◽  
Explorer Mission ◽  
Hybrid Plasma ◽  
Potential Habitats ◽  
Advance Method ◽  
Using Data ◽  
Current Advance

<p>Galilean moons are embedded in Jupiter’s giant magnetosphere. The jovian plasma particles interact with the atmosphere of the moons, exchanging momentum and energy, and generate different phenoma such as aurora, electric current, etc.</p> <p>The exploration of the Galilean moons, and in particular Ganymede and Europa considered as potential habitats, are listed among the main objectives of the ESA JUpiter ICy moon Explorer mission. In preparation of future observations, a simulation effort is conducted to describe the Europa moon-magnetosphere system as well as a study of radio wave propagation in the environments of Ganymede and Europa using a ray tracing code.</p> <p>LatHyS is a hybrid 3D, multi-species and parallel simulation model which is based on a kinetic description of ions and a fluid description of electrons. The model is based on the CAM-CL algorithm that Alan Matthews¹ outlined in 1994. It allows to describe the interaction between the jovian plasma and the moon environments. As Ganymede's environment has already been implemented, we propose to enrich the model by completing it with Europa's – jovian plasma interaction and to optimize it in order to improve the accuracy of the results.</p> <p>Artemis-P, developed by Gautier² in 2013, is a ray tracing code that calculates the trajectory of waves through a given environment. Planetary environments are anisotropic and inhomogeneous, so that radio waves can undergo refraction, reflection, scattering, diffraction, interference, etc. between the source and the detector. The ray tracing methods allow to treat the refraction and reflection phenomena at large scales compared to the wavelength. The proposed work is to adjust this program to the environments of Ganymede and Europa using data from LatHyS simulations.</p> <p> </p> <p align="left">Références :</p> <p align="left"><sup>1</sup> Alan P. Matthews, Current Advance Method and Cyclic Leapfrog for 2D Multispecies Hybrid Plasma Simulations, Journal of Computational Physics, Volume 112, Issue 1, 1994, Pages 102-116, ISSN 0021-9991, https://doi.org/10.1006/jcph.1994.1084.</p> <p align="left">² Anne-Lise Gautier. Étude de la propagation des ondes radio dans les environnements planétaires. Planétologie et astrophysique de la terre [astro-ph.EP]. Observatoire de Paris, 2013. Français. tel-01145651v2</p>

scholarly journals Energetic ion depletions near Europa and Io: the effect of plumes and atmospheric charge exchange

2020 ◽  
Author(s):  
Hans Huybrighs ◽  
Christiaan van Buchem ◽  
Aljona Blöcker ◽  
Elias Roussos ◽  
Norbert Krupp ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Energetic Particle ◽  
Depletion Region ◽  
The Moon ◽  
Particle Detector ◽  
Particle Tracing ◽  
Energetic Ions ◽  
Galilean Moons ◽  
Upper Limits ◽  
Inert Body

<p><strong>Introduction</strong></p><p>The flux of energetic ions (protons, oxygen and sulfur) near the Galilean moons were measured by the Energetic Particle Detector (EPD) on the Galileo mission (1995 - 2003). Near Galilean moons (such as Io and Europa) depletions of the energetic ion flux, of several orders of magnitude, were identified.</p><p>Such energetic ion depletions can be caused by the absorption of these particles onto the moon’s surfaces or by the loss due to charge exchange with neutral molecules in the atmospheres or potential plumes. To interpret the depletion features in the EPD data, a Monte Carlo particle tracing simulation has been conducted. The expected fluxes of the energetic ions are simulated under different scenarios including those with and without an atmosphere or plume. By comparing the simulated flux [YF1] to the EPD data, we investigate the cause of the depletion features with particular focuses on Europa and Io flybys.</p><p><strong>Results</strong></p><p>For Europa we report the following findings:</p><ul><li>For flyby E12 we find that a global atmosphere should produce a depletion region along the trajectory that is symmetrical to the closest approach, for energetic protons in the energy range of 80-220 keV. No such feature is visible in the data. Upper limits of the atmosphere are consistent with surface densities (⩽ 10<sup>8 </sup>cm<sup>-3</sup>) and scale heights (50-350 km) of previous studies. We find that a depletion of energetic protons (80-220 keV) occurring before closest approach is consistent with the field perturbations associated with a plume. This plume features coincides in time with the plume reported by Jia et al., 2018.</li> <li>For flyby E26 we find that the depletions of energetic protons (80-220 keV) are consistent with a simulation that takes into account the perturbations of the fields as calculated by an MHD simulation and atmospheric charge exchange. Furthermore, a depletion feature occurring shortly after closest approach is consistent with the field perturbations associated with a plume, located near the plume reported by Arnold et al., 2019.</li> <li>From these investigations, we confirm, independently from previous reports, that the Galileo spacecraft could have passed near plumes.</li> </ul><p>For Io we report the following results:</p><ul><li>We identify regions of proton (80-220 keV) depletions during Io flybys I24, I27 and I31 extending beyond one Io radius. The depletions features are not consistent with Io as an inert body. We investigate atmospheric charge exchange as a cause for the depletions.</li> </ul>

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