An assessment of the contamination acquired by IDPs during atmospheric deceleration

The E-layer of the terrestrial mesosphere, between 80 and 110 km altitude, is derived from meteoric ablation. Concentrations of Na and Fe, contributed by meteoric vapor, have been monitored in the mesosphere, and both individual meteors and average concentration profiles have been measured. Individual interplanetary dust particles (IDP's) entering the earth's atmosphere must pass through the mesospheric layers rich in meteoric volatile elements. Limits on the extent to which individual IDP's can be contaminated by meteoric volatile elements during deceleration in the upper atmosphere can be established by considering the extreme cases: the direct passage of an IDP through a meteoric vapor trail or the passage of an IDP through the mesospheric layer rich in meteoric volatiles. It appears the interaction of IDP's with meteoric vapor during deceleration in the upper atmosphere does not produce significant contamination of IDP's as they decelerate in the upper atmosphere.