REGOLITH DEPOSITS ON TINY ASTEROIDS RYUGU AND ITOKAWA AND THEIR SIMILARITY TO AEOLIAN DEPOSITS

The surfaces of small bodies are generally covered by regolith materials, which appear to be random piles of fragmental debris. However, their sizes and aerial distributions often show some characteristics, which would be resulted from the forming or evolutional processes. For example, all regolith materials on both bodies are in gravitationally stable condition, which indicate that they are arranged after their depositions. Some areas show characteristics of debris migrations as often observed at terrestrial debris flows. Intriguingly, fines are often depleted to show as often seen as desert pavement. Dr. Zimbelman has extensively studied planetary flows and aeolian deposits, whose insights have strong impacts on analyzing these features. By comparing the morphological characteristics, I will discuss about geological processes working on small bodies of only less than 1km in diameter.