A low Earth orbit (LEO) is generally defined as an orbit below an altitude of 2,000 km. Given the rapid orbital decay of objects below approximately 200 km, the commonly accepted definition for LEO is between 160–2,000 km (100–1,240 miles) above the Earth's surface. With the exception of the lunar flights of the Apollo program, all human spaceflights have taken place in LEO (or were suborbital). The altitude record for a human spaceflight in LEO was Gemini 11 with an apogee of 1,374.1 km. All manned space stations to date, as well as the majority of artificial satellites, have been in LEO.

Objects in LEO encounter atmospheric drag in the form of gases in the thermosphere (approximately 80–500 km up) or exosphere (approximately 500 km and up), depending on orbit height. LEO is an orbit around Earth between the atmosphere and below the inner Van Allen radiation belt. The altitude is usually not less than 300 km because that would be impractical due to the larger atmospheric drag.

Equatorial low Earth orbits (ELEO) are a subset of LEO. These orbits, with low inclination to the Equator, allow rapid revisit times and have the lowest delta-v requirement of any orbit. Orbits with a high inclination angle are usually called polar orbits.

A geocentric orbit involves any object orbiting the Earth, such as the Moon or artificial satellites. Currently there are approximately 2,465 artificial satellites orbiting the Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. Over 16,291 previously launched objects have decayed into the Earth's atmosphere.

The following is a list of different geocentric orbit classifications.

Monument Valley (Navajo: Tsé Biiʼ Ndzisgaii, meaning valley of the rocks) is a region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, the largest reaching 1,000 ft (300 m) above the valley floor. It is located on the Arizona-Utah state line (around 36°59′N 110°6′W / 36.983°N 110.1°W / 36.983; -110.1), near the Four Corners area. The valley lies within the range of the Navajo Nation Reservation, and is accessible from U.S. Highway 163.

The area is part of the Colorado Plateau. The floor is largely siltstone of the Cutler Formation, or sand derived from it, deposited by the meandering rivers that carved the valley. The valley's vivid red color comes from iron oxide exposed in the weathered siltstone. The darker, blue-gray rocks in the valley get their color from manganese oxide.

The buttes are clearly stratified, with three principal layers. The lowest layer is Organ Rock shale, the middle de Chelly sandstone and the top layer is Moenkopi shale capped by Shinarump siltstone. The valley includes large stone structures including the famed Eye of the Sun.