English: Robotic exploration missions provide NASA vast amounts of data to prepare for future human exploration missions and learn more about the universe. Objective: Researchers aim to identify rock types that lie beneath the surface and uncover the complex history of the moon. Description: The LRO Camera LROC continues to reveal contrasting materials weathering out of slopes or being uncovered by impact events. In the upper image, black patches appear on the wall of a volcanic rille, which is a narrow channel. The darkest spots on the moon are usually associated with explosive volcanic materials called pyroclastics, but these are blocky and uneven, unlike other identified pyroclastic deposits. The bottom image is a collapsed lava tube, or pit, 90 m deep and wide. Future geologists could explore lava tubes like this to understand what lies beneath the surface. Time Frame: Both images were acquired by LROC during the ongoing LRO Exploration Mission. Application: Identifying regions where the complex lunar subsurface is exposed will enable future explorers to sample materials and better understand the way the landscape was formed. NASA Identifier: 452642main_2010-17A