The Meteorite Flux at the Surface of Mars

Estimates of the average meteorite flux at the Martian surface are presented.These estimates were derived by generating a meteorite flux distribution for the top of the Martian atmosphere, and then adjusting this flux for mass loss and deceleration in the atmosphere.The top-of-the-atmosphere meteorite flux distribution was based on meteorite fall, asteroid, and lunar and Martian crater data.The effects of the Martian atmosphere were evaluated by performing a numerical integration of the mass loss and deceleration equations of the physical theory of meteors through an atmospheric model based on Mariner IV data.Results of this preliminary study indicate the Martian surface is afforded varying degrees of protection from impacting meteorites in the mass range 10 grams to 1 metric ton.Meteorites with masses greater than 1 metric ton are little affected by passage through the atmosphere while meteorites of ~ 10 grams mass and less are completely decelerated by the Martian atmosphere and impact the Martian surface with terminal free-fall velocities.