%unimsg 0 entry/pluto/v0 -- The first document written against @vocab/encyclopaedia/v0, and the entry -- the vocabulary was tested on. -- -- Pluto was chosen because it exercises the three things the vocabulary claims -- the prior art cannot do. Its classification CHANGED in 2006 without its -- identity changing, so a fact needs a clock. Its classification is STILL -- DISPUTED, by people who publish, so a fact needs two values and no winner. -- And its numbers were replaced wholesale by one spacecraft in 2015, so a -- superseded value is a fact about the subject rather than a mistake to -- overwrite. -- -- The prose is deliberately plain. What is being tested is the shape. pluto @entry/pluto/v0 { conforms -> @vocab/encyclopaedia/v0 title "Pluto" role :article status :draft at 2026-09-01 locale { language "en", direction :ltr } -- =================================================================== -- THE SUBJECT -- =================================================================== subject { name "Pluto" also-known-as [ | name conditions | "134340 Pluto" "the designation carried since the minor-planet number was assigned in 2006" | "Pluto-Charon" "used where the pair is treated as one system" ] names-in { fr "Pluton" de "Pluto" ja "冥王星" ar "بلوتو" zh "冥王星" } identifiers [ | scheme value resolver | "wikidata" "Q339" "https://www.wikidata.org/entity/" | "minor-planet" "134340" :none | "jpl-sbdb" "134340" "https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=" ] scope "The body itself. The system of Pluto and its five moons is treated here only where the pair's barycentre bears on the body's own description; Charon has its own entry." not-to-be-confused-with [ -> @entry/pluto-mythology, -> @entry/plutonium, ] } -- =================================================================== -- THE LEAD -- =================================================================== abstract "Pluto is a body of the outer solar system, orbiting the sun at a mean distance of about forty times the earth's at an inclination and eccentricity unlike those of the eight planets. It was found in 1930 and counted as the ninth planet for seventy-six years; in 2006 the International Astronomical Union adopted a definition of `planet` that excludes it, and it has been classified as a dwarf planet since. That reclassification remains disputed by part of the planetary-science community, which uses a definition based on the body's own physical properties rather than on its orbital neighbourhood. It was visited once, by New Horizons in July 2015, which replaced almost every measured quantity in this entry." -- =================================================================== -- CLASSIFICATION -- =================================================================== branch-extensions { planetary-science { parent :astronomy covers "the solar system's bodies, their surfaces, interiors and atmospheres, and the missions that observe them" maps-to [ | scheme value | "ddc" "523.4" | "wikidata" "Q10933" ] } history-of-science { parent :history covers "the development of scientific knowledge and of the institutions that produce it, treated historically" maps-to [ | scheme value | "ddc" "509" | "wikidata" "Q29026" ] } } classify { kind :celestial-body branches [ :planetary-science, :history-of-science, :sociology ] period { range { from 1930-02-18 } } maps-to [ | scheme value | "ddc" "523.482" | "lcc" "QB701" | "udc" "523.4" | "wikidata" "Q339" | "wikipedia-category" "Pluto" ] } -- =================================================================== -- THE PROPERTIES THIS ENTRY'S CLAIMS USE -- -- A corpus would reach these through :uses rather than declare them per -- entry, which is what the vocabulary says and what a second entry would -- immediately want. They are inline here because there is not yet a second -- entry, and a property set with one consumer is a file that hides a -- decision rather than sharing one. -- =================================================================== properties { body-class { datatype :enum temporality :temporal holds "the class of body the subject is held to be, under the definition the source is applying" single true values [ | value means | :planet "a planet, under the definition the citing source uses" | :dwarf-planet "a dwarf planet, under the IAU 2006 definition" | :minor-planet "a minor planet or small solar-system body" | :satellite "a body in orbit around another that is not the sun" ] maps-to [ | scheme value | "wikidata" "P31" ] } discovered-by { datatype :entity temporality :fixed holds "the person or body credited with the discovery" maps-to [ | scheme value | "wikidata" "P61" ] } discovery-date { datatype :date temporality :fixed single true holds "the date of the observation on which the discovery rests" maps-to [ | scheme value | "wikidata" "P575" ] } mean-radius { datatype :number temporality :fixed unit :km single true holds "the mean radius of the body" applies-to [ :celestial-body ] maps-to [ | scheme value | "wikidata" "P2120" ] } mass { datatype :number temporality :fixed unit :kg single true holds "the mass of the body" maps-to [ | scheme value | "wikidata" "P2067" ] } orbital-period { datatype :number temporality :fixed unit :yr single true holds "the sidereal orbital period" maps-to [ | scheme value | "wikidata" "P2146" ] } semi-major-axis { datatype :number temporality :fixed unit :au single true holds "the semi-major axis of the orbit" } satellites { datatype :number temporality :temporal unit :count single true holds "how many natural satellites are known" } minor-planet-number { datatype :external-id temporality :fixed single true holds "the number assigned by the Minor Planet Center" } } -- =================================================================== -- THE CLAIMS -- -- The two body-class claims from 2006 onward are the point of the example. -- The property is :single, they overlap, and they differ — so both are -- marked :disputed and neither is the value. The vocabulary refuses the -- document if either marking is dropped, which is the one arithmetic check -- it can perform over its own claims. -- =================================================================== claims [ { property :discovery-date, value 1930-02-18, source -> @sources.tombaugh-1946, basis :reported }, { property :discovered-by, value -> @entry/clyde-tombaugh, source -> @sources.tombaugh-1946, basis :reported, note "The search was Lowell Observatory's and the plates were Tombaugh's. Credit to the observatory rather than to the observer is a second claim this entry does not make, because no source it holds makes it." }, { property :body-class, value :planet, as-of { from 1930-03-24, to 2006-08-24 }, source -> @sources.lowell-circular-1930, basis :attributed, status :former, note "Announced by Lowell Observatory and adopted by use rather than by any decision. There was no definition of `planet` to satisfy, which is the fact the 2006 resolution exists to change." }, { property :body-class, value :dwarf-planet, as-of { from 2006-08-24 }, source -> @sources.iau-2006-5a, locator "Resolution 5A, clause 2", basis :attributed, status :disputed }, { property :body-class, value :planet, as-of { from 2006-08-24 }, source -> @sources.runyon-2017, basis :attributed, status :disputed, qualifiers { definition "geophysical" }, note "A definition resting on the body's own properties — hydrostatic equilibrium and nothing about its orbital neighbourhood — advanced by members of the New Horizons team and used in their published work. It is a live position and not a historical one, which is why it is :disputed and not :former." }, { property :minor-planet-number, value { scheme "minor-planet", value "134340" }, source -> @sources.mpc-circular-2006, basis :reported }, { property :mean-radius, value km 1188.3, precision km 1.6, source -> @sources.nimmo-2017, basis :measured, note "From New Horizons imaging. Every pre-encounter figure was an estimate from occultations and differed by tens of kilometres." }, { property :mass, value kg 1.303e22, precision kg 0.003e22, source -> @sources.stern-2015, basis :calculated }, { property :orbital-period, value yr 247.94, source -> @sources.jpl-sbdb, basis :calculated }, { property :semi-major-axis, value au 39.48, source -> @sources.jpl-sbdb, basis :calculated }, { property :satellites, value count 5, as-of { from 2012-07-11 }, source -> @sources.showalter-2012, basis :measured, note "Charon in 1978, Nix and Hydra in 2005, Kerberos in 2011, Styx in 2012. The count is open: the entry does not claim none will be found." }, ] -- =================================================================== -- THE BODY -- =================================================================== body [ @discovery { block :section, heading "Discovery" blocks [ { block :para, runs [ { text "The search that found Pluto was undertaken at " }, { link -> @entry/lowell-observatory, text "Lowell Observatory" }, { text " to locate a body whose gravity was thought to perturb the orbits of Uranus and Neptune. " }, { term "Planet X" }, { text " was predicted from residuals later shown to be errors of measurement, so the prediction was wrong and the search that it motivated succeeded anyway " }, { cite -> @sources.standish-1993 }, { text ". The plates on which the body appears were taken on " }, { date 1930-01-23 }, { text " and " }, { date 1930-01-29 }, { text ", and the motion between them was found on " }, { date 1930-02-18 }, { text "." }, ] }, { block :para, runs [ { text "The name was proposed by an eleven-year-old in Oxford and adopted by the observatory in March of the same year " }, { cite -> @sources.lowell-circular-1930 }, { text ". Its first two letters are also the initials of " }, { link -> @entry/percival-lowell, text "Percival Lowell" }, { text ", which the observatory noted at the time." }, ] }, ] }, @reclassification { block :section, heading "Reclassification" blocks [ { block :para, runs [ { text "Discoveries in the " }, { link -> @entry/kuiper-belt, text "Kuiper belt" }, { text " from 1992 onward found many bodies on comparable orbits, and in 2005 one — " }, { link -> @entry/eris, text "Eris" }, { text " — was measured as more massive than Pluto " }, { cite -> @sources.brown-2007 }, { text ". The choice that followed was between admitting an unknown number of further planets and adopting a definition that excluded them all." }, ] }, { block :timeline, heading "The decision and what followed" rows [ | date happened | 1992-08-30 "the first Kuiper belt object after Pluto is found, and Pluto stops being alone on its kind of orbit" | 2005-01-05 "Eris is identified, and is later measured as more massive than Pluto" | 2006-08-24 "the IAU adopts Resolutions 5A and 6A. Pluto is a dwarf planet and the prototype of a class" | 2006-09-07 "the Minor Planet Center assigns the number 134340" | 2015-07-14 "New Horizons passes at 12500 km, and every measured quantity in this entry is replaced" | 2017-03-21 "a definition based on hydrostatic equilibrium is proposed to the Lunar and Planetary Science Conference and is not adopted" ] }, { block :para, runs [ { text "The IAU definition has three clauses; Pluto satisfies the first two and fails the third, which requires a body to have cleared the neighbourhood of its orbit " }, { cite -> @sources.iau-2006-5a, locator "Resolution 5A" }, { text ". The objection to it is that the third clause is a fact about where a body is rather than about what it is, so that the same body would change class if it were moved " }, { cite -> @sources.runyon-2017 }, { text ". This entry records both positions and settles neither: see the two " }, { emphasis "body-class", level 1 }, { text " claims above, which is where the disagreement is stored." }, ] }, { block :aside, heading "Why the vote is in the sociology branch" blocks [ { block :para, runs [ { text "The reclassification is routinely cited as a case of a scientific category being settled by a show of hands at a meeting most of the discipline did not attend, and the arguments made about it are as much about authority as about Pluto " }, { cite -> @sources.messeri-2010 }, { text ". That is why " }, { emphasis ":sociology", level 1 }, { text " is the third branch of this entry and not a stretch." }, ] }, ] }, ] }, @physical { block :section, heading "Physical description" blocks [ { block :para, runs [ { text "Pluto's radius is " }, { quantity km 1188.3 }, { text ", about two thirds of the moon's, and its mass is roughly a fifth of the moon's " }, { cite -> @sources.nimmo-2017 }, { text ". The surface is dominated by nitrogen ice with methane and carbon monoxide, and the smooth plain informally called Sputnik Planitia is a basin of nitrogen ice with convection cells tens of kilometres across " }, { cite -> @sources.mckinnon-2016 }, { text "." }, ] }, { block :table, caption "Orbit, as of the 2015 encounter" columns [ "quantity", "value", "source" ] rows [ | "semi-major axis" "39.48 au" "JPL small-body database" | "orbital period" "247.94 yr" "JPL small-body database" | "eccentricity" "0.2488" "JPL small-body database" | "inclination" "17.16°" "JPL small-body database" ] }, { block :para, runs [ { text "The eccentricity brings Pluto inside Neptune's orbit for about twenty years of each revolution, most recently between 1979 and 1999. The two do not approach each other, because the orbits are locked in a three-to-two resonance " }, { cite -> @sources.malhotra-1993 }, { text "." }, ] }, ] }, ] -- =================================================================== -- RELATIONS -- =================================================================== relations [ { type :part-of, target -> @entry/solar-system }, { type :broader, target -> @entry/dwarf-planet }, { type :contrast-with, target -> @entry/eris, because "the body whose discovery forced the definition" }, { type :see-also, target -> @entry/kuiper-belt }, { type :see-also, target -> @entry/new-horizons }, { type :main-article, target -> @entry/iau-definition-of-planet, because "the definition is summarised here and treated at length there" }, ] -- =================================================================== -- SOURCES -- =================================================================== sources { lowell-circular-1930 { kind :web title "Announcement of the discovery and naming of Pluto" publisher "Lowell Observatory" date 1930 url "https://lowell.edu/" accessed 2026-08-30 note "Cited from the capture rather than from the circular itself, which this repository does not hold. The distinction is real and is why :basis on the claims that use it is :attributed." } tombaugh-1946 { kind :article title "The search for the ninth planet, Pluto" author [ "Tombaugh, Clyde W." ] in "Astronomical Society of the Pacific Leaflets" date 1946 } iau-2006-5a { kind :standard title "Resolution 5A: Definition of a Planet in the Solar System" publisher "International Astronomical Union" date 2006-08-24 url "https://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf" accessed 2026-08-30 quotes "A planet is a celestial body that is in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and has cleared the neighbourhood around its orbit." note "Quoted because both disputed claims turn on the wording of the third clause." } mpc-circular-2006 { kind :standard title "Minor Planet Circular 57525: numbering of (134340) Pluto" publisher "Minor Planet Center" date 2006-09-07 } runyon-2017 { kind :paper title "A geophysical planet definition" author [ "Runyon, Kirby D.", "Stern, S. Alan", "Lauer, Tod R.", "Grundy, Will", "Summers, Michael E.", "Singer, Kelsi N." ] in "Lunar and Planetary Science Conference XLVIII" date 2017 identifiers [ | scheme value | "lpsc-abstract" "1448" ] } nimmo-2017 { kind :paper title "Mean radius and shape of Pluto and Charon from New Horizons images" author [ "Nimmo, Francis", "Umurhan, Orkan", "Lisse, Carey M." ] in "Icarus" date 2017 identifiers [ | scheme value | "doi" "10.1016/j.icarus.2016.06.027" ] } stern-2015 { kind :paper title "The Pluto system: initial results from its exploration by New Horizons" author [ "Stern, S. Alan" ] in "Science" date 2015-10-16 identifiers [ | scheme value | "doi" "10.1126/science.aad1815" ] } mckinnon-2016 { kind :paper title "Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigour" author [ "McKinnon, William B." ] in "Nature" date 2016-06-02 identifiers [ | scheme value | "doi" "10.1038/nature18289" ] } malhotra-1993 { kind :paper title "The origin of Pluto's peculiar orbit" author [ "Malhotra, Renu" ] in "Nature" date 1993 identifiers [ | scheme value | "doi" "10.1038/365819a0" ] } standish-1993 { kind :paper title "Planet X: no dynamical evidence in the optical observations" author [ "Standish, E. Myles" ] in "The Astronomical Journal" date 1993 identifiers [ | scheme value | "doi" "10.1086/116575" ] } brown-2007 { kind :paper title "The mass of dwarf planet Eris" author [ "Brown, Michael E.", "Schaller, Emily L." ] in "Science" date 2007-06-15 identifiers [ | scheme value | "doi" "10.1126/science.1139415" ] } showalter-2012 { kind :web title "Hubble discovers a fifth moon orbiting Pluto" publisher "Space Telescope Science Institute" date 2012-07-11 url "https://hubblesite.org/" accessed 2026-08-30 } messeri-2010 { kind :paper title "The problem with Pluto: conflicting cosmologies and the classification of planets" author [ "Messeri, Lisa R." ] in "Social Studies of Science" date 2010 identifiers [ | scheme value | "doi" "10.1177/0306312709347809" ] } jpl-sbdb { kind :dataset title "JPL Small-Body Database entry for 134340 Pluto" publisher "Jet Propulsion Laboratory" url "https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=134340" accessed 2026-08-30 note "An orbit solution is recomputed as observations accumulate, so the figures taken from it are dated by :accessed and not by a publication date. A dataset with no version is the weakest source in this entry." } wikipedia-pluto { kind :capture title "Pluto" publisher "Wikipedia" date 2026-08-30 url "https://en.wikipedia.org/wiki/Pluto" accessed 2026-08-30 note "The capture, as a source. Nothing in this entry currently rests on it alone: every claim traces to a work the article cited, which took a working afternoon and is the honest cost of the source rule." } } -- =================================================================== -- CAPTURE -- =================================================================== capture { from "English Wikipedia" locator "https://en.wikipedia.org/wiki/Pluto" revision "1263540111" retrieved 2026-08-30 licence "CC-BY-SA-4.0" attribution "Wikipedia contributors, `Pluto`, English Wikipedia, revision 1263540111, licensed CC BY-SA 4.0. This entry is adapted from it and carries the same licence." extent :partial note "The article's structure, its lead and four of its sections were the starting point; the prose here is rewritten rather than copied, and the claims were re-sourced to the works the article cited rather than to the article. WHAT WAS DROPPED: the exploration, moons, orbit-detail and in-culture sections, the infobox rows with no recoverable source, all images, and every navigation template. Three infobox values had no citation in the article and could not be traced; they are absent rather than cited to the capture, which is a stricter choice than the vocabulary requires." } -- =================================================================== -- COVERAGE -- =================================================================== coverage { depth :standard as-of 2025-12-31 emphasis "the reclassification and the dispute about it. The physical description is a summary and the orbital figures are one dataset deep" omits [ | thing lives-instead-in | "the New Horizons mission" "-> @entry/new-horizons" | "the five satellites" "-> @entry/charon and the four entries beside it" | "atmospheric structure and its collapse" "not written. This is a gap and not a decision" | "Pluto in fiction and in popular culture" "not written" ] unresolved 11 note "ELEVEN OF THE TWELVE ENTRIES THIS ONE LINKS TO DO NOT EXIST. The corpus is one document, so every link but the self-reference dangles, and the vocabulary's refusal of a dangling :link run is therefore the first thing a checker of this file will report. That is the correct behaviour and the entry says so rather than hiding it: a corpus of one entry is not a corpus, and this file is a test of the shape." } contributors [ { name "written for this repository", role :author }, ] }