Meteoric dust in the upper atmosphere

The results of a rocket-borne sampling of meteoric dust which was performed in Sweden in 1962 are presented. This sampling was performed in the absence of any visible evidence of particulate concentration at the altitude of 75 to 98 km. Electron microscopic examination of the recovered particles showed a cumulative diameter distribution of the form N = Aδ−p, where p≈ 2. A cutoff in this distribution occurs at δ ≈ 0.05 micron. From the data a meteoric flux is computed, which is compared with a revised calculation from the earlier Venus Flytrap experiment. The agreement is within a factor of 3.