Processes of Ice in the Solar System

M. Arakawa and A, Kouchi, " Impact processes of ice in the solar system" in High -... 

The committee surveyed the inventory of environments in the solar system and asked which non-Earth ones might be suited to fife of the terran type. Such locales are few, unless there are laws not now understood that could govern the early stages of the self-organization of biochemical structures and processes that could lead inevitably to evolving life forms.15 Subsurface Mars and the putative sub-ice oceans of the Galilean satellites are the only locales in the solar system (other than Earth itself) that are clearly compatible with terran biochemistry. 

There are many icy bodies in addition to comets in the solar system they are icy satellites and Kuiper belt objects. Icy satellites of the Jupiter and Saturn systems were observed by spacecraft to clarify their densities and surface compositions. As a result, it is widely accepted that the main component of icy satellites is water ice, and the existence of water ice is confirmed by the observation of near infrared reflectance spectra. Icy satellites were revealed to have various surface morphologies and geologic activities depending on their origin and the thermal evolution process. Most of the icy satellites have densities from 1 to 2 g/cm which means that these bodies are a mixture of ices and silicates. Icy satellites were formed by collisional accretion of small porous bodies. These bodies could be ice-silicate mixture and the porosity was corrupted according to their growth. Therefore, impact properties of an ice-silicate mixture with various porosities are necessary to be clarified in order to study the formation process of icy satellites. I review systematic experimental results on impact of ice-silicate mixture in Section 3. 

Carbon compounds in the solar system can be traced in planetary atmospheres, on planetary surfaces, comets, asteroids, meteorites and in the interplanetary medium. Gas and solid state chemistry within the solar nebula was responsible for new organic material (49,50). Many organic compounds have been identified on outer solar system bodies, some of them originating in the surface ices through energetic processing (4). 

---