关于这张图
AS16-114-18412 (16-27 April 1972) --- The gnomon and color patch, one of the Apollo Lunar Hand Tools (ALHT), is deployed atop a lunar rock, in this photograph taken by one of the Apollo 16 astronauts during their lunar surface extravehicular activity (EVA) at the Descartes landing site. The gnomon is used as a photographic reference to establish local vertical sun angle, scale, and lunar color. The color patch, mounted on one of the legs of the tripod, provides a larger target for accurately determining colors in color photography. A portion of Flag Crater can be seen in the background. While …
