pluto became a dwarf planet in 2005.
pluto became a dwarf planet in 2005.
what year did pluto become a dwarf planet?
2005
finally, from a purely linguistic point of view, there is the dichotomy that the iau created between 'planet' and 'dwarf planet'. the term 'dwarf planet' arguably contains two words, a noun (planet) and an adjective (dwarf). thus, the term could suggest that a dwarf planet is a type of planet, even though the iau explicitly defines a dwarf planet as "not" so being. by this formulation therefore, 'dwarf planet' and 'minor planet' are best considered compound nouns. benjamin zimmer of language log summarised the confusion: "the fact that the iau would like us to think of dwarf planets as distinct from 'real' planets lumps the lexical item 'dwarf planet' in with such oddities as 'welsh rabbit' (not really a rabbit) and 'rocky mountain oysters' (not really oysters)." as dava sobel, the historian and popular science writer who participated in the iau's initial decision in october 2006, noted in an interview with national public radio, "a dwarf planet is not a planet, and in astronomy, there are dwarf stars, which are stars, and dwarf galaxies, which are galaxies, so it's a term no one can love, dwarf planet." mike brown noted in an interview with the smithsonian that, "most of the people in the dynamical camp really did not want the word "dwarf planet," but that was forced through by the pro-pluto camp. so you're left with this ridiculous baggage of dwarf planets not being planets."
definition of planet
the term "dwarf planet" has itself been somewhat controversial, as it could imply that these bodies are planets, much as dwarf stars are stars. this is the conception of the solar system that stern promoted when he coined the phrase. the older word "planetoid" ("having the form of a planet") has no such connotation, and is also used by astronomers for bodies that fit the iau definition. brown states that "planetoid" is "a perfectly good word" that has been used for these bodies for years, and that the use of the term "dwarf planet" for a non-planet is "dumb", but that it was motivated by an attempt by the iau division iii plenary session to reinstate pluto as a planet in a second resolution. indeed, the draft of resolution 5a had called these median bodies "planetoids," but the plenary session voted unanimously to change the name to "dwarf planet." the second resolution, 5b, defined "dwarf planets" as a subtype of "planet", as stern had originally intended, distinguished from the other eight that were to be called "classical planets". under this arrangement, the twelve planets of the rejected proposal were to be preserved in a distinction between eight "classical planets" and four "dwarf planets". resolution 5b was defeated in the same session that 5a was passed. because of the semantic inconsistency of a "dwarf planet" not being a planet due to the failure of resolution 5b, alternative terms such as "nanoplanet" and "subplanet" were discussed, but there was no consensus among the csbn to change it.
dwarf planet