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.

Nontraditional JR and Sub-millimeter space-borne telescope concept basing on blind-type parabolic multi-ring mirror is proposed and discussed. Preliminary results for optimization of mirror parameters by means of computer simulation are presented.

Experimental and methodical possibilities of modern observations of the solar K-corona have been analyzed. It is shown that for obtaining information on matter distribution and dynamics in the internal solar corona, it is necessary to measure both its polarization component and its total radiation in the continuum. In order to reduce the atmospheric and instrumental background, the employment of K-coronameters with an apodized liquid mirror is proposed. Such coronameters should operate in the near infrared range and be installed at a latitude zone where the Sun can be observed in the zenith.Information concerning the distribution of matter in the internal solar corona is key in understanding the origin and interrelation of physical processes in the solar atmosphere. Meanwhile, modern heliophysics actually is lacking systematic data on the dynamics of the proper coronal matter in the region from the chromosphere up to the altitudes about 0.5 R e .Non-eclipse observations being performed both by the ground-based facilities and the devices placed beyond the troposphere, can be conditionally divided into the following two types. The first one concerns the observations in the spectral ranges for which the coronal plasma radiation is equal to or even more intensive than that of the denser layers of the solar atmosphere, i.e., radio frequencies, far ultra-violet, or X-ray bands. Over these ranges, the radiation mechanisms (such as braking, recombination, magnetobraking, forbidden transitions between the levels, i.e., the emission lines of heavily ionized elements and, maybe, a synchroton mechanism) are determined by a wide scope of conditions and parameters (Vasilyev, 1975). Among these parameters (e.g. general degree of plasma ionization, energy of radiating particles, temperature, etc.) the matter density in the source region is not a principal one, as a rule (House et al., 1981). Besides, a reliable detection of the density factor from the observed characteristics for the above-mentioned types of radiation of the internal corona encounters fundamental difficulties (Hang, 1979).The second type of observation is related to the visible or neighbouring ranges of the spectrum. For the altitudes above the photosphere of interest for us, the 'electron corona' glow in the continuous spectrum (specifically, the K-corona) is caused by Thomson scattering of the low-layer solar atmosphere radiation from the coronal plasma free electrons. As this mechanism is non-selective, and the relation between the K-corona brightness and the electron (and, hence, the proton) concentration is unambiguous, the measurements of the continuous spectrum made with the use of the colorimeter monitoring (Vasilyev, 1989) yield the only true information on the distribuSolar Physics 132: 271-277, 1991. 9 1991 Kluwer Academic Publishers. Printed in Belgium.

A nearsurface brittle fracture caused by the thermoacoustic stress wave from a heavy ion track passing through material is investigated. The size and shape of a possible damageldestruction zone around the ion track are found by accounting for the ionization loss nonuniformity and attenuation of the generated stress wave and temperature. The probability of spacecraft sensor system damage is discussed on the basis of a damage zone around the ion trajectory.

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