In the Solar System, a planet is said to be inferior or interior with respect to another planet if its orbit lies inside the other planet's orbit around the Sun. In this situation, the latter planet is said to be superior to the former. In the reference frame of the Earth, in which the terms were originally used, the inferior planets are Mercury and Venus, while the superior planets are Mars, Jupiter, Saturn, Uranus and Neptune. Dwarf planets like Ceres or Pluto and most asteroids are 'superior' in the sense that they almost all orbit outside the orbit of Earth.
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.[2]
Planets in each category
When Earth is stated or assumed to be the reference point:
"Inferior planet" refers to Mercury and Venus, which are closer to the Sun than Earth is.
"Superior planet" refers to Mars, Jupiter, Saturn, Uranus, and Neptune (the latter two added later), which are farther from the Sun than Earth is.
The terms are sometimes used more generally; for example, Earth is an inferior planet relative to Mars.
Other planetary terms
Interior planet now seems to be the preferred term for astronomers. Inferior/interior and superior are different from the terms inner planet and outer planet, which designate those planets which lie inside the asteroid belt and those that lie outside it, respectively. Inferior planet is also different from minor planet or dwarf planet. Superior planet is also different from gas giant.
References
^Lakatos, Imre; Worrall, John; Currie, Gregory (1980). Worrall, John; Currie, Gregory (eds.). The Methodology of Scientific Research Programmes. Cambridge University Press. p. 186. ISBN0-521-28031-1.
- setting this to "bottom-right" will display a (rather large) icon linking to the graphic, if desired
Notes:
Details on the new coding for clickable images is here: [1]
The smaller planets have a bit of an overlap just to ensure they're locatable, especially in the belts.
While it may look strange, it's important to keep the codes for a particular system in order. The clickable coding treats the first object created in an area as the one on top.
- I've placed moons on "top" so that their smaller circles won't disappear "under" their respective planets or dwarf planets.
The "poly" code would be more appropriate for the moons of Jupiter, Saturn, and Uranus. However, there appears to be a bug with that aspect of the code.
- I've compensated by using oversized circles for those moon groups, and tucking them UNDER their planets for now.
The Sun is a rectangle as that approximates the edge closely enough for the purposes of this template.
I've guessed as to the boundaries for the KB, SD, and OC - if they need adjustment, load the image into Paint and use the pencil tool to find the appropriate coordinates.
