Atmospheric Noble Gases: Solar-Wind Bombardment of Extraterrestrial Dust as a Possible Source Mechanism.

A source mechanism for the noble gases in the earth's atmosphere may be the solar-wind bombardment of extraterrestrial dust. Calculations based on estimates of recent influx of dust to the earth, quiet solar-wind intensity, argon abundance in the solar wind, and assumed Poynting-Robertson lifetimes of small particles in space agree within a factor of 5 with the present amounts of argon-36 and argon-38 in the atmosphere.