Washington: NASA's MESSENGER mission has unveiled the first global digital elevation model (DEM) of Mercury, revealing in stunning detail the topography across the entire innermost planet. It will also pave the way for scientists to fully characterise Mercury's geologic history. "The wealth of these data has already enabled and will continue to enable exciting scientific discoveries about Mercury for decades to come," said Susan Ensor, software engineer at The Johns Hopkins University's Applied Physics Laboratory (APL). This new model reveals a variety of interesting topographic features, including the highest and lowest points on the planet. The highest elevation on Mercury is at 4.48 km above Mercury's average elevation, located just south of the equator in some of Mercury's oldest terrain. The lowest elevation, at 5.38 km below Mercury's average, is found on the floor of Rachmaninoff basin, an intriguing double-ring impact basin suspected to host some of the most recent volcanic deposits on the planet. More than 100,000 images were used to create the new model. "This has become one of my favourite maps of Mercury. Now that it is available, I'm looking forward to it being used to investigate this epic volcanic event that shaped Mercury's surface," added Nancy Chabot, instrument scientist for the Mercury Dual Imaging System (MDIS) in a NASA statement. "During its four years of orbital observations, MESSENGER revealed the global characteristics of one of our closest planetary neighbours for the first time. The data from the mission will continue to be utilised by the planetary science community for years to come.