COMETARY ICE TEXTURE AND THE THERMAL REVOLUTION OF COMETS

KOSI comet simulation experiments have shown strong evidence for significant modifications of the texture of porous ice within typical experiment durations of a few ten hours. Initially, the textures of the fluffy ice samples were obviously not in their equilibrium states. During the cause of the experiments the textures modified through growth of the bond sizes between individual grains which caused significant increases in compressive strength and intrinsic thermal conductivity. The near-surface layers of cometary nuclei amy evolve similarly as they are heated during perihelion passage. As a consequence, the heat wave may penetrate into increasingly deeper layers to depths greater than generally expected.