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Frequent observations of ion beams moving out from Saturn’s plasma environment hints at the generation of ion Bernsteinâ€"Greeneâ€"Kruskal (BGK) modes. As the plasma environments of Saturn and its moon Enceladus are characterized by the ubiquitous presence of massive negatively charged dust particles, the existing BGK theory for electron-ion plasma models cannot address this scenario. This manuscript develops a theoretical model for studying ion BGK modes in dusty plasmas. The analysis reveals that the presence of dust in the plasma enhances the stability of BGK modes. As the dust density increases, the effect of other parameters on stability, such as the electron temperature, becomes negligible. The model is developed by assuming that electrons and ions follow a kappa distribution, featuring a long tail trend in the superthermal component, in agreement with observations. Different scenarios with either electrons or ions obeying a Maxwell or kappa distribution function have been considered. A thorough analysis of the trapped ion distribution function considering various combinations indicates that a plasma where electrons are in thermal equilibrium and ions follow kappa distribution is the least favorable system for the generation of BGK modes. [ABSTRACT FROM AUTHOR]

We present an analysis of 450 solitary wave pulses observed by the Langmuir Probe and Waves instrument on the Mars Atmosphere and Volatile EvolutioN spacecraft during its five passes around Mars on 2015 February 9. The magnitude and duration of these pulses vary between 1 and 25 mV mâˆ'1 and 0.2â€"1.7 ms, respectively. The ambient plasma conditions suggest that these pulses are quasi-parallel to the ambient magnetic field and can be considered electrostatic. These pulses are dominantly seen in the dawn (5â€"6 LT) and afternoon-dusk (15â€"18 LT) sectors at an altitude of 1000â€"3500 km. The frequencies of these electric field pulses are close to the ion plasma frequency (i.e., f pi ≤ f ef ≪ f pe), which suggests that their formation is governed by ion dynamics. The computer simulation performed for the Martian magnetosheath plasma hints that these pulses are ion-acoustic solitary waves generated by drifted ion and electron populations and their spatial scales are in the range of few ion Debye lengths (1.65â€"10 λ di). This is the first study to report and model solitary wave structures in the Martian magnetosheath. [ABSTRACT FROM AUTHOR]