The Marshall Engineering Thermosphere Model (MET) is essentially a modified Jacchia 1970 model that includes some spatial and temporal variation patterns of the Jacchia 1971 model. In addition to thermospheric densities and temperatures the well-documented code provides also several often used parameters like gravitational acceleration and specific heat. MET was developed at NASA's Marshall Space Flight Center in Huntsville primarily for engineering applications. The MSIS model is generally considered superior to MET because of its larger data base and its more elaborate mathematical formalism.