Landforms on Asteroid 25143-Itokawa: A geomorphological perspective on periglacial origin and meltwater history

摘要

Asteroid surface geology offers a full range of opportunities for geomorphologists to participate in the analysis of landform distributions, deposit composition, source areas for sediments, age estimations, and the reconstruction of geohydrological records. A recent touchdown (2005) on 25143-Itokawa, a Near Earth Object (NEO), by the Hayabusa Spacecraft provides imagery (released, 2008, by the Japanese Aerospace Agency) that allows the analysis of data relevant to geomorphologists. The abbreviated interpretation of landform distributions on Itokawa discussed below provides a preliminary analysis of landform morphogenesis in a cold climate with near-zero gravity. The analysis generates several questions related to source of water, cause of fluid propagation and explanations of previously unrecognized processes of denudation.