THE THERMAL-DESTRUCTION OF SOLIDS NEAR THE SUN

We consider the thermal evolution of both icy and non-icy solids movin g in highly eccentric orbits using an analytical solution of the heat diffusion equation. The thermal stresses which arise inside and at the surface of solids can exceed by several orders of magnitude the tidal stresses in the neighbourhood of the Sun for all material considered. This means that thermal disintegration is the most important factor i n the evolution of cometary and meteorite-like bodies. This problem ma y be directly connected with the origin of the variable part of the in frared radiation excess in the F-corona observed at 4R(.) and 9R(.) fr om the Sun. The possible scenario of the disintegration of the distant solids due to the thermal stresses is also given.