SURFACE THERMOELASTIC EROSION OF ATMOSPHERELESS SOLAR-SYSTEM BODIES UNDER BOMBARDMENT BY MULTICHARGE COSMIC-RAY IONS

The mechanism of ion-stimulated erosion of atmosphereless solar system bodies is suggested and investigated. A theoretical model for the bri ttle surface erosion resulting under the effect of multicharge ion cos mic rays is analyzed. It is shown that the thermoelastic waves origina ted in the energetic track of a very heavy ion can result in the near- surface stresses exceeding the dynamic tensile strength of the surface material for any atmosphereless solar system body. The thermoelastic wave surface arrival yields brittle erosion of the material and ejecti on of this latter fragments (the track-breaking process). Thus ejected dust grains have piano-oblong shape, average mass on the order of 10( -17) g and velocity up to 400 m/sec providing the surface erosion rate of 10(-1) divided by 3 . 10(2) Angstrom/year (near the Earth orbit) w hich depends upon the surface material (rock or ice). Possible track-b reaking consequences, in particular, presence of the dust fraction of ultramicron grains and their aggregates on the lunar surface are discu ssed. Near the bodies with the radii from 10 to 300 km predicted is th e existence of extended dust cocoons consisting of ultramicron and sub micron grains. Smaller objects (asteroids, comets, smallest satellites of planets, meteoroids, etc.) can serve sources of permanent dust win d of ultramicron and submicron sized grains escaping from their surfac es. The interplanetary dust yield owing to the ion-stimulated erosion of these bodies is not less than 10(12) g/year. Possible interpreting in the frames of track-breaking process some observational data and ef fects, including existence of dust brains with the mass of 10(-18) div ided by 10(-17) g near the Halley's comet and the nature of 2060 Chiro n dust coma is discussed. To prove the theory, observational identific ation and investigation of dust phenomena complex related to the ion-s timulated erosion of atmosphereless bodies, suggested is employing ext reme ultraviolet and far infrared/submillimeter wavelengths, as well a s polarimetric methods.