Example of the distributions of the pre-atmospheric speed, V_∞, of meteoroids at 100 km altitude from the ground, used for the estimation of the exposure of Mini-EUSO as a function of the meteoroid mass, M_∞. The black line plots the assumed theoretical distribution, ρ_t, given by ECSS (2008) and the green line reports the distribution of meteoroids, ρ_i, for M_∞ = 10^−4.3 kg observable by Mini-EUSO if assuming the luminous efficiency, τ = τ(V_∞), given by Ceplecha & McCrosky (1976). For this mass bin, the exposure of Mini-EUSO is estimated to be X_i ≃ 0.68X_nom from Eq. D.5.