Inferior and superior planets the orbit of Earth. These terms were originally used in the geocentric cosmology of Claudius Ptolemy to differentiate as inferior those planets (Mercury and Venus) whose epicycle remained co-linear with the Earth and Sun, and as superior those planets (Mars, Jupiter, and Saturn) that did not. In the 16th century, the terms were modified by Copernicus, who rejected Ptolemy's geocentric model, to distinguish a planet's orbit's size in relation to the Earth's. When Earth is stated or assumed to be the reference point: The terms are sometimes used more generally; for example, Earth is an inferior planet relative to Mars.
The Sun Saboteurs Earth Quarter"; and in the UK under the original title in the omnibus "Two Novels". In the future, Earth has been devastated by war and disease and supports only a primitive agrarian society. Most Earthmen live elsewhere, as émigrés on planets that are populated by alien species. The author suggests that the human species is the only one plagued by "original sin", i.e. by an innate tendency to lie, cheat, kill; aliens have come to accept these traits without understanding them. The story takes place among a group of humans in the "Earth Quarter", a ghetto on the planet Palu