A landing footprint, also called a landing ellipse, is the area of uncertainty of a

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...

landing zone In military terminology a landing zone (LZ) is an area where aircraft can land. In the United States military, a landing zone is the actual point where aircraft, especially helicopters, land (equivalent to the commonwealth landing point.) In ...

on an astronomical body. After

atmospheric entry Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the ent ...

, a non-powered spacecraft will land in an area depending upon entry angle, entry mass, atmosphere and drag. It is therefore impossible to know the spacecraft's landing point with absolute precision. By simulating varying reentry courses, a numerical simulation will produce a plot resembling a footprint. The footprint size depends on the

confidence interval In frequentist statistics, a confidence interval (CI) is a range of estimates for an unknown parameter. A confidence interval is computed at a designated ''confidence level''; the 95% confidence level is most common, but other levels, such as 9 ...

used to develop the map.

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Further reading