Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology. | Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology. |