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;
Catholic (term) then also to the teaching of the church fathers and the councils". The term "Catholic" is commonly associated with the whole of the church led by the Roman Pontiff, the Catholic Church. Other Christian churches that use the description "Catholic" include the Eastern Orthodox Church and other churches that believe in the historic episcopate (bishops), such as the Anglican Communion. Many of those who apply the term "Catholic Church" to all Christians object to the use of the term to designate what they view as only one church within what they understand as the "whole" Catholic Church. In the English