Estimate of the heights z_end and densities n_end at which nuclei are destroyed as a function of M_ocos³φ_∗ for specified P₆. Note that results are very sensitive to cosφ_∗ and to P₆. To the left of the knee ablation vaporizes the nucleus before ram pressure exceeds the strength of nucleus material. To the right ram pressure drives destructive explosion of the nucleus. It is clear that a very large range of masses is destroyed within a few scale heights in the chromosphere and that for all plausible masses and parameters, all nuclei are destroyed above the photosphere. This figure is available in colour in electronic form.