Why does the moon have a layer of powdery "soil" on its surface? a) the soil exists because the moon accreted from powdery material after a giant impact blasted earth. b) the soil is the result of the same processes that make powdery sand on earth. c) volatiles escaping from the moon's interior bubble upward and make the soil. d) it's the result of gradual erosion by micrometeorites striking the moon. e) large impacts shattered lunar rock to make this soil.