Considered a mythic substance until recently, dry quicksand is loose sand that behaves like ordinary quicksand but contains no water and operates in a different manner. Though accounts of whole caravans being swallowed up by the substance have been discounted as folklore, researchers have demonstrated that aerating fine sand reduces its bulk density and creates a dry quicksand that could envelop an entire vehicle. How did fear of dry quicksand affect the planning of the Apollo moon missions? Discuss