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 House (Central, Alaska) Central House (Central, Alaska) The Central House, also known as Erickson & Stade's, at Mile 128 on the Steese Highway in Central, Alaska, was a log structure built in 1926 by Riley Erickson and John Stade, replacing an 1894 log and sod structure that was burned in a 1925 fire. It served as a roadhouse restaurant and hotel, and was listed on the National Register of Historic Places in 1978. Located on Crooked Creek, it was deemed significant for its historical role as a central focus for miners of other creeks that were Birch Creek tributaries and for serving travelers.