Geocentric model the coordinate system in order to predict the motions of planetary bodies, though doing so may make calculations easier to perform or interpret. A geocentric coordinate system can be more convenient when dealing only with bodies mostly influenced by the gravity of the Earth (such as artificial satellites and the Moon), or when calculating what the sky will look like when viewed from Earth (as opposed to an imaginary observer looking down on the entire solar system, where a different coordinate system might be more convenient). The Ptolemaic model of the solar system held sway into the early modern age;
Central City, Nebraska school. In the 1950s, Nebraska Central College closed (1953) but a new hospital was built in 1959. In 1975, an explosion and fire destroyed an entire city block, but Central City still reached its largest population to date at 3,083 people in 1980. Central City's population has declined slightly since then. Six places in or near Central City are listed in the National Register of Historic Places. To qualify for listing in the National Register of Historic Places, a place (e.g., building, landmark, or location) must be at least 50 years old and have one or more of the following