Titan’s “Average” Ionospheric Structures from Cassini

Abstract

The decadal observations of Titan’s neutral atmosphere and ionosphere by the Ion and Neutral Mass Spectrometer mass spectrometer and other instruments on board the Cassini spacecraft at the Saturnian system provide a precious data set concerning the large-scale structure of Titan’s upper ionosphere. An attempt is made in this study to generate average 3D ion density distributions for different ion species by using a simple approximation of the solar zenith angle dependence. Both altitude dependence and neutral gas number density dependence of the ion density distributions will be presented. This empirical approach allows a comprehensive visualization of the global properties of Titan’s ionosphere that could be useful as engineering models for future missions to Titan.

Vibrationally Resolved Inner‐Shell Photoexcitation of the Molecular Anion C2−

“…[1][2][3][4][5][6][7] Using neutral molecules as targets, many fundamental questions have been addressed in recent years, e. g., the localization of the core hole, [8] complex many-electron relaxation effects, [9][10][11][12] or the role of the photon momentum in the molecular dissociation process. [13,14] Molecular ions have received much less attention despite their important role as transient species in many chemical environments such as flames, [15] Earth's and Titan's ionospheres, [16,17] or interstellar gas clouds. [18,19] This is due to the fact that only much lower target densities can be prepared for targets of free charged particles as compared to what can be achieved for neutral species.…”

Vibrationally Resolved Inner-Shell Photoexcitation of the Molecular Anion C$_2^-$

“…Using neutral molecules as targets, many fundamental questions have been addressed in recent years, e.g., the localization of the core hole [8] , complex many-electron relaxation effects [9][10][11][12] , or the role of the photon momentum in the molecular dissociation process [13,14] . Molecular ions have received much less attention despite their important role as transient species in many chemical environments such as flames [15] , Earth's and Titan's ionospheres [16,17] , or interstellar gas clouds [18,19] . This is because of the fact that only much lower target densities can be prepared for targets of free charged particles as compared to what can be achieved for neutral species.…”