Speleology meteorology and cartography to develop portraits of caves as complex, evolving systems. Prior to the mid-nineteenth century the scientific value of caves was considered only in its contribution to other branches of science, and cave studies were considered part of the larger disciplines of geography, geology or archaeology. Very little cave-specific study was undertaken prior to the work of Édouard-Alfred Martel (1859–1938), the 'father of modern speleology', who through his extensive and well-publicised cave explorations introduced in France the concept of speleology as a distinct area of study. In 1895 Martel founded the Société de Spéléologie, the first organization devoted
Exploration of Mars and first European probe to achieve a soft landing on Mars. NASA's Mars Exploration Rover Mission (MER), started in 2003, is an ongoing robotic space mission involving two rovers, Spirit (MER-A) and Opportunity, (MER-B) exploring the Martian surface geology. The mission's scientific objective is to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The mission is part of NASA's Mars Exploration Program, which includes three previous successful landers: the two Viking program landers in 1976; and Mars Pathfinder probe in 1997. The "Mars Reconnaissance Orbiter" (MRO) is a