A brief topical review of current knowledge available for predicting the characteristics of sandstorms is presented. Particular emphasis is placed on extrapolations to Mars where saltation of loose surface material appears to be a necessary condition for initiation of observed dust storms. Considerable data are now available to predict threshold winds under earth's environmental conditions, but techniques for predicting the quantity of material transported and the height and velocity to which it travels are still crude. Extrapolation of current knowledge to Mars is probably sufficient only for estimating purposes and landing craft design. The upcoming Viking landing mission on Mars will, it is hoped, shed additional light on the problem.