Miranda is an odd moon with chaotic surface terrain that makes it appear jumbled up and patched together. There are strange surface markings and huge canyons that reach depths up to 12 miles, more than 15 times the depth of the Grand Canyon. In addition, Miranda is much smaller than the Earth and therefore has less gravity. So if you were to drop a rock into the canyon it would have a long way to fall and it would fall slowly. Approximately nine minutes would pass before the rock hit the bottom. To learn more about Miranda, follow this link.