Plasma Waves Around Venus and Mars

Abstract

Plasma waves are observed around almost all the solar system objects – Sun, planets and their satellites, comets, interplanetary medium, etc. The plasma environment around a planet has sufficient plasma density and temperature to sustain plasma waves. A number of plasma waves are observed in planetary magnetospheres – Mercury, Earth, Jupiter, Saturn, Uranus and Neptune. Venus and Mars do not possess a global magnetic field but have plasma waves around them. Plasma waves play an important role in the dynamics of the plasma environment around a solar system object by controlling the scattering and loss of energetic charged particles. Also, plasma waves provide an important diagnostic tool by revealing various characteristic frequencies of the plasma, from which quantities such as the electron density can be computed. Although Venus and Mars are the nearest neighbors of Earth on its either side, these two planets are not much explored with plasma wave detection instrumentation. Only 4 missions out of 23 missions to Venus and only 3 out of 42 missions to Mars carry plasma wave detection instruments with them. In this review paper, the plasma waves observed so far around Venus and Mars are presented along with the plasma waves that could exist around these two planets but are yet to be observed and an optimized suite of plasma wave instruments for these observations.