Mountain

A mountain is an elevated part of a planet's surface, generally with steep sides and significant exposed bedrock, and while there is no single universal definition, a mountain is usually taken to rise more than about 2,000 feet, 610 meters, above its surroundings, distinguishing it from a hill by its greater height and steepness. Mountains form through tectonic forces, volcanism and erosion acting over millions of years, and once uplift stops, weathering, mass wasting and glacial or river erosion gradually wear them back down. Their elevation gives mountains distinctly colder climates than lowland areas at the same latitude, shaping the ecosystems found at different altitudes, and while people farm, mine and recreate in mountain country, the terrain's difficulty makes mountains generally less inhabited than lowlands. Mount Everest is Earth's highest peak above sea level at about 8,850 meters, Mauna Kea rises further in total height from the ocean floor, and Olympus Mons on Mars dwarfs any mountain on Earth at roughly 21,171 meters.