A paper compass that uses the sun to create shadows on a circle with topographic lunar features. It was used during the Stand Up EVA (SEVA) to take bearings on landmarks and allowed Mission Control to triangulate the position of the Lunar Module (LM). It was also prepared and tested for the EVAs because Apollo 15 was the first time astronauts drove beyond the horizon and needed a backup navigation system for the Lunar Roving Vehicle (LRV). If the LRV's navigation system had failed and the LM was out of sight, astronauts could have aligned the compass with the mountains and navigated back to the LM.
