Cumulative mass distribution of interplanetary meteoroids (Grün et al. 1985, top); meteoroid lifetimes against mutual collisions and Poynting-Robertson drag (middle); and cumulative mass distributions of meteoroid populations in IMEM (Dikarev et al. 2005a, bottom) including the interstellar dust, which is ignored in this paper owing to the tiny sizes of the constituent particles. The flux of meteoroids with m> 10^-5 g is lower in IMEM than in the Grün model since the impact velocities of big meteoroids are higher at 1 AU from the Sun in IMEM and they produce larger craters on the lunar rocks than in the Grün model, which assumed a single impact velocity for all meteoroid sizes.