March 10, 2010
north to the left image of Apollo 15 area constructed by Howard Fink, New York
The problem with the Moon is that the illumination always comes from a limited range of azimuths, so the shadows best emphasize features that are perpendicular to those directions. But with a three dimensional model of a lunar scene you can rotate it to have illumination from any direction. Here, the Sun is to the south, casting a shadow from the Hadley Delta peak over the big bend in the Hadley Rille. Such rotations can be performed within a computer using digital terrain models (DTM), and Howard has demonstrated how those same lines of zeros and ones can be transformed into a physical depiction of the lunar surface. He used a USGS digitized version of the old topographic map of the Apollo 15 area, which he read into Mathematica, converted into a 3D model with Maya, and printed with a rapid-prototyper or 3-D printer. Howard was very kind and gave me one of these 5" x 7" models which he mounted in a cherry frame. With the new Kaguya and LRO DTMs it will be possible for many people to make their own models of any part of the Moon, using a 3-D printer at a local university or service center. I am especially pleased to see this because in my review of technology and education I suggested that 3-D printers would soon be able to bring models of planetary landforms into our hands. I am so happy to have one!
Rükl plate 22