The interaction of the solar wind with planetary environments generates a variety of perturbations, such as electromagnetic disturbances, energetic particle events, and surface sputtering. Various past and ongoing missions have revealed different processes of interplanetary plasma interaction with different planets and allowed for comparative investigations of planetary space weathers and space climates.

The magnetospheres, ionospheres, and upper atmospheres of planets and moons are also governed by additional sources of variability that are even less understood: atmospheric waves (i.e., tides, gravity waves, planetary waves…) propagating into upper atmospheres “from below” and, for giant planets, the exhaust gases and plasmas generated by active moons (Io in the Jovian magnetosphere, Enceladus at Saturn, Triton at Neptune etc.). These processes that find their sources in dense planetary atmospheres and moons add variable mass, momentum, and energy to their host planet's plasma environment.

A key challenge for space science is understanding both the individual effects and the complex interplay of these sources, which collectively shape the unique space weather and climate of each planet. This session will address these fundamental processes, including:
(a) solar wind and energetic particle interaction with planets, moons, asteroids and comets
(b) impacts of atmospheric dynamics and its variability on upper atmospheres and ionospheres
(c)impacts of the dynamics and variability of active moons on their host magnetosphere
(e) plasma interactions with exospheres, dust and surfaces
(f) surface space weathering
(g) potential impact of planetary environment on technological space systems
(h) inter-comparisons of planetary environments