The terms "inferior planet" and "superior planet" were originally used in the geocentric cosmology of Claudius Ptolemy to differentiate as 'inferior' those planets (Mercury and Venus) whose epicycle remained collinear with the Earth and Sun, compared to the 'superior' 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.
- "Inferior planet" is used in reference to Mercury and Venus, which are closer to the Sun than the Earth is.
- "Superior planet" is used in reference to Mars, Jupiter, Saturn, (and later additions Uranus and Neptune), which are farther from the Sun than the Earth is.
The terms are sometimes used more generally: for instance, the Earth is an inferior planet as seen from Mars.
This classification is different from the terms inner and outer planet, which designate those planets which lie inside the asteroid belt and those that lie outside it, respectively. "Inferior planet" is also very different to minor planet or dwarf planet.
Famous quotes containing the words inferior and, inferior, superior and/or planets:
“The rights of citizenship will be taken away from all Jews and other non-Aryans. They are inferior and therefore enemies of the state. It is the duty of all true Aryans to hate and despise them.”
—Charlie Chaplin (1889–1977)
“I find very reasonable the Celtic belief that the souls of our dearly departed are trapped in some inferior being, in an animal, a plant, an inanimate object, indeed lost to us until the day, which for some never arrives, when we find that we pass near the tree, or come to possess the object which is their prison. Then they quiver, call us, and as soon as we have recognized them, the spell is broken. Freed by us, they have vanquished death and return to live with us.”
—Marcel Proust (1871–1922)
“Whatever offices of life are performed by women of culture and refinement are thenceforth elevated; they cease to be mere servile toils, and become expressions of the ideas of superior beings.”
—Harriet Beecher Stowe (1811–1896)
“Why are all these dolls falling out of the sky?
Was there a father?
Or have the planets cut holes in their nets
and let our childhood out,
or are we the dolls themselves,
born but never fed?”
—Anne Sexton (1928–1974)