Slope and Roughness of the Moon's Surface (IMAGE) NASA/Goddard Space Flight Center Caption The colors in this image reveal information about the slope and roughness of the moon's surface. The slope of the surface depends on the spatial scale over which we choose to measure it, and the roughness is related to the slope. Here, the red channel shows slopes at the largest scale (half a kilometer or about one-third mile), green in between, and blue at the shortest scale (about 50 meters or 165 feet). By looking at three scales simultaneously, researchers can identify features of interest, such as the maria, which are smooth at large scales and rough at short scales; these features appear blue. The rough terrain of relatively young craters appears white, while basin ejecta -- material thrown out of the large craters at the time of impact -- has an orange color, meaning that this material is rougher at the large scale than at the small scale. The map is adapted from the Journal of Geophysical Research (2011) Credit NASA/California Institute of Technology Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.