Speleology by a large number of human activities. Dam construction, limestone quarrying, water pollution and logging are just some of the disasters that can devastate or destroy underground biological communities. Speleologists also work with archaeologists in studying underground ruins, tunnels, sewers and aqueducts, such as the various inlets and outlets of the Cloaca Maxima in Rome. Speleology Speleology is the scientific study of caves and other karst features, their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). The term "speleology" is also sometimes applied to the recreational activity of
Exploration of Neptune academic groups have proposed and worked on future scientific missions to visit Neptune. Some mission plans are still active, while others have been abandoned or put on hold. After the "Voyager" flyby, NASA's next step in scientific exploration of the Neptune system is considered to be a flagship orbiter mission. Such a hypothetical mission is envisioned to be possible in the late 2020s or early 2030s. Another one proposed for the 2040s is called the Neptune-Triton Explorer (NTE). NASA has researched several other project options for both flyby and orbiter missions (of similar design as the "Cassini–Huygens" mission to Saturn).