  The space electron-ion-positive dust plasma system containing isothermal
inertialess electron species, cold inertial ion species, and stationary
positive (positivively charged) dust species is considered. The basic features
of one dimensional (1D) planar and nonplanar subsonic solitary waves are
investigated by the pseudo-potential and reductive perturbation methods,
respectively. It is observed that the presence of the positive dust species
reduces the phase speed of the ion-acoustic waves, and consequently supports
the subsonic solitary waves with the positive wave potential in such a space
dusty plasma system. It is observed that the cylindrical and spherical subsonic
solitary waves significantly evolve with time, and that the time evolution of
the spherical solitary waves is faster than that of the cylindrical ones. The
applications of the work in many space dusty plasma systems, particularly in
Earth's mesosphere, cometary tails, Jupiter's magnetosphere, etc. are
addressed.
