Surface thermoelastic erosion of atmosphereless solar system bodies under bombardment by multicharge cosmic ray ions

Abstract

The mechanism of ion-stimulated erosion of atmosphereless solar system bodies is suggested and investigated. A theoretical model for the brittle surface erosion resulting under the effect of multicharge ion cosmic rays is analyzed. It is shown that the thermoelastic waves originated 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 ejection of this latter fragments (the track-breaking process), Thus ejected dust grains have plano-oblong shape, average mass on the order of 10-l' g and velocity up to 400 m/set providing the surface erosion rate of 10-l f 3 lo* &year (near the Earth orbit) which depends upon the surface material (rock or ice). Possible track-breaking consequences, in particular, presence of the dust fraction of ultramicron grains and their aggregates on the lunar surface are discussed. Near the bodies with the radii from 10 to 300 km predicted is the existence of extended dust cocoons consisting of ultramicron and submicron grains. Smaller objects (asteroids, comets, smallest satellites of planets, meteoroids, etc.) can serve sources of permanent dust wind of ultramicron and submicron sized grains escaping from their surfaces. The interplanetary dust yield owing to the ion-stimulated erosion of these bodies is not less than lOi g/year. Possible interpreting in the frames of track-breaking process existence of dust grains with the mass of IO-'* + some observational data and effects, including 10-r' g near the Halley's comet and the nature of 2060 Chiron dust coma is discussed. To prove the theory, observational identification and investigation of dust phenomena complex related to the ion-stimulated erosion of atmosphereless bodies, suggested is employing extreme ultraviolet and far infrared/submillimeter wavelengths, as well as polarimetric methods.

Attogram dust grains in the solar system

“…For a more in-depth study of the surface track-breaking mechanism let us define the geometrical and kinematic adjectives of an ASSB fragment shattered in the interaction of a cosmic ray ion with the surface material, employing the model from Kalinichenko et al (1996). Consider the interaction of an axial-symmetrical elastic wave excited in the ion track with an ASSB-space plane boundary.…”

“…The positive half-wave of a thermoelastic impulse contributes most to the ASSB surface ion-enhanced erosion mechanism. Therefore, as in Kalinichenko et al (1996), from now on we will use the characteristics of the model-track generated impulse. The model track, or the so-called energetic track is a uniformly heated cylindrical region with radius R c and containing the bulk of the energy losses of a multicharged ion penetrating under the surface.…”

“…The estimated magnitudes of R c , overheating temperatures T c and thermoelastic stresses σ c originating in the energetic track are given in our earlier work Kalinichenko et al (1996).…”

“…However, the conditions enabling the intense formation of ADGs actually exist in the solar system too, as well as in other planetary/protoplanetary systems. Earlier (Kalinichenko et al 1996) we showed that the so-called track-breaking can be such a formation mechanism.…”

Is near-surface ice the driver of dust activity on 67P/Churyumov-Gerasimenko

“…A variety of physical processes has been investigated as the potential drivers of the cometary dust release. Micrometeorite bombardment of the surface (Chapman 2004), electrostatic charging of the nucleus (Mendis et al 1981;Nordheim et al 2015), and the mechanism of ion-stimulated erosion due to an interaction of cometary nuclei with the solar wind (Kalinichenko et al 1996) have been examined. However, the lifting force that arises as a result of nearsurface ice sublimation is considered as the most common lifting force since the article of Whipple.…”