Comets and cometary debris in the solar system

Abstract

The orbital behavior, size, surface temperature, and surface vapor pressure of comets are shown to be determined from and by their observed rapid evolution of gas and dust while they are visible. The numerical density and size distribution of the cometary and asteroidal debris that freights the solar system are inferred from solar eclipse observations, and the probable history of the dust particles is reviewed. The erosion of space‐vehicle surfaces by microscopic dust predicted to condense on the planets and space‐vehicle surface penetration by stones are shown to be either nonexistent or easily surmountable problems.