Last week, I told you we would show you a new map of Mercury based on the January MESSENGER flyby. Here it is, kindly provided by one of NASA’s master mappers, Robert Gaskell of the Planetary Science Institute in Altadena, California.
This image is an anaglyph — a flat image that simulates a three-dimensional view — of the fault scarp Beagle Rupes as it cuts across the crater Sveinsdóttir. The area shown here is about 160 miles (257 kilometers) square. The view angle is 45 degrees.
This anaglyph is equivalent to an interplanetary “topo map,” showing the elevations of the land surface. Gaskell is now engaged in making topography maps for Mercury based on flat images taken from orbit by Mariner 10 in 1973 and MESSENGER. It’s not a simple task.
Using software he developed, Gaskell deduces slopes on Mercury based on how the surface looks under different lighting conditions. It’s like photographing a mountain at different times of day, and reconstructing the mountain’s exact shape based on the shifting shadows cast on its surface.
Hard work pays off. Gaskell’s topo maps of the asteroid Itokawa show surface details as small as 16 inches (40 centimeters). That earned him a NASA Exceptional Achievement medal.
Eventually, the new Mercury maps will help scientists learn more about Mercury’s geology and history. I’ll check back with Dr. Gaskell from time to time to see how the work is going, and let you know what I find out.