--- title: "Planet" language: "en" type: "Entity" summary: "Planets in our solar system." keywords: - Mercury - Venus - Earth - Mars - Jupiter - Saturn - Uranus - Neptune - planet - planets - solar system - gas giant - gas giants - terrestrial planet - terrestrial planets - orbit - orbits - astronomy canonical_url: "https://reference.wolfram.com/language/ref/entity/Planet.html" source: "Wolfram Language Documentation" related_guides: - title: "Entity Types" link: "https://reference.wolfram.com/language/guide/EntityTypes.en.md" --- # Planet Planets in our solar system. [Related Interpreter](https://reference.wolfram.com/language/ref/interpreter/Planet.en.md) Entity["Planet", name] or Entity[...] represents an entity of type "Planet". Entity[...][prop] gives the value of a specified property. Entity[...][{prop1, …}] gives the value of a list of properties. Entity[...][prop, {quali -> vali, …}] gives the value of a specified property modified by qualifier rules quali -> vali. Entity[...][Dated[prop, date]] gives the value of a property associated with a particular date specification. EntityClass["Planet", {propi -> speci, …}] represents a class of entities with values of propi defined by speci. ## Sample Entities * Entity["Planet", "Earth"]Entity["Planet", "Jupiter"]Entity["Planet", "Mars"]Entity["Planet", "Mercury"]Entity["Planet", "Neptune"]Entity["Planet", "Saturn"]Entity["Planet", "Uranus"]Entity["Planet", "Venus"]**…** ## Sample Entity Classes * EntityClass["Planet", "InnerPlanet"]EntityClass["Planet", "OuterPlanet"]EntityClass["Planet", "RingedPlanet"]**…** ## Properties | | | | -------------------------------- | ------------------------------------- | | AbsoluteMagnitudeH | absolute magnitude H | | Age | age | | Albedo | albedo | | AlphanumericName | alphanumeric name | | AlternateNames | alternate names | | Altitude | altitude | | AltitudeMaximum | next maximum altitude | | AngularDiameterFromEarth | angular diameter | | AngularRadiusFromEarth | angular radius | | Aphelion | largest distance from the Sun | | Apoapsis | largest distance from Sun | | ApoapsisTime | next apoapsis time | | ApoapsisTimeLast | last apoapsis time | | ApparentAltitude | apparent altitude | | ApparentMagnitude | apparent magnitude | | AscendingNodeLongitude | longitude of ascending node Ω | | AtmosphericComposition | atmospheric composition | | AtmosphericPressure | atmospheric pressure | | AtmosphericScaleHeight | atmospheric scale height | | AuthalicDiameter | authalic diameter | | AuthalicRadius | authalic radius | | AverageDistanceFromEarth | average distance from Earth | | AverageOrbitalCentripetalForce | average orbital centripetal force | | AverageOrbitDistance | average orbit distance | | AverageOrbitVelocity | average orbit velocity | | AverageTemperature | average temperature | | AverageVelocityAroundSun | average heliocentric velocity | | Azimuth | azimuth | | BondAlbedo | bond albedo | | BooleanRise | above the horizon | | Classes | classes | | Color | color | | Constellation | constellation | | CylindricalEquidistantTexture | cylindrical equidistant texture | | DailyTimeAboveHorizon | daily time above horizon | | Declination | declination | | Density | mean density | | Diameter | average diameter | | Discoverers | discoverers | | DiscoveryDate | discovery date | | DistanceFromEarth | distance from Earth | | DistanceFromSun | distance from Sun | | EccentricAnomaly | eccentric anomaly | | Eccentricity | orbital eccentricity | | EffectiveTemperature | effective temperature | | EntityClasses | entity classes | | EntityTypeList | entity type list | | EquatorialAngularVelocity | equatorial angular velocity | | EquatorialCircumference | equatorial circumference | | EquatorialDiameter | equatorial diameter | | EquatorialFrequency | equatorial frequency | | EquatorialRadius | equatorial radius | | EquatorialVelocity | equatorial velocity | | EscapeVelocity | escape velocity | | FarthestPlanet | farthest planet | | GalacticLatitude | galactic latitude | | GalacticLongitude | galactic longitude | | GeocentricEclipticLatitude | geocentric ecliptic latitude | | GeocentricEclipticLongitude | geocentric ecliptic longitude | | Glyph | astrological symbol | | GravitationalConstantMassProduct | gravitational constant mass product | | Gravity | gravity | | GreenwichHourAngle | Greenwich hour angle ... gitude | heliocentric ecliptic longitude | | HelioCoordinates | heliocentric ecliptic XYZ coordinates | | HelioVelocityVector | heliocentric velocity vector | | HillRadius | Hill radius | | Image | image | | Inclination | orbital inclination | | LocalHourAngle | local hour angle | | MajorAxis | orbital major axis | | Mass | mass | | MaximalAltitudeTime | next maximum altitude time | | MaximumOrbitalCentripetalForce | maximum orbital centripetal force | | MaximumTemperature | maximum temperature | | MeanAnomaly | mean anomaly | | MeanMotion | mean motion | | MinimumOrbitalCentripetalForce | minimum orbital centripetal force | | MinimumTemperature | minimum temperature | | MinorAxis | orbital minor axis | | MomentOfInertia | rotational moment of inertia | | MoonCount | number of moons | | Moons | moons | | NAIFIdentifier | NAIF identifier | «20 rows removed» | PeriapsisArgument | argument of periapsis ω | | PeriapsisLongitude | longitude of periapsis ϖ | | PeriapsisTime | next periapsis time | | PeriapsisTimeLast | last periapsis time | | Perihelion | nearest distance from the Sun | | PolarCircumference | polar circumference | | PolarDiameter | polar diameter | | PolarRadius | polar radius | | Radius | average radius | | RetrogradeApparentMotionQuery | apparent direction | | RightAscension | right ascension | | RingSystemInnerDiameter | ring system inner diameter | | RingSystemInnerRadius | ring system inner radius | | RingSystemOuterDiameter | ring system outer diameter | | RingSystemOuterRadius | ring system outer radius | | RingSystemThickness | ring system thickness | | RingSystemWidth | ring system width | | RiseTime | next rise | | RocheLimit | Roche limit | | RotationalAngularMomentum | rotational angular momentum | | RotationPeriod | rotation period | | Satellites | known satellites | | SemimajorAxis | orbital semimajor axis | | SemiminorAxis | orbital semiminor axis | | SetTime | next set | | Shape | shape | | SiderealHourAngle | sidereal hour angle | | SolarConjunctionTimeLast | last solar conjunction time | | SolarConjunctionTimeNearest | nearest solar conjunction time | | SolarConjunctionTimeNext | next solar conjunction time | | SolarDay | solar day | | SolidAngleFromEarth | solid angle | | SphereOfInfluenceRadius | sphere of influence radius | | StationaryOrbitRadius | stationary orbit radius | | StationaryOrbitSpeed | stationary orbit speed | | SurfaceArea | surface area | | TexturedSurface | 3D graphic | | TransitTime | next transit time | | TrueAnomaly | true anomaly | | VelocityAroundSun | instantaneous heliocentric velocity | | Volume | volume | | VolumetricDiameter | volumetric diameter | | VolumetricRadius | volumetric radius | | ZenithAngle | zenith angle | ## Details * ``"Planet"`` entities include all eight planets recognized by the International Astronomical Union. * ``"Planet"`` entity classes include inner and outer planets in addition to ringed planets. * Some properties are available for the ``"Planet"`` entity type as a whole and can be given using the form ``EntityValue["Planet", property]``. Such properties include: | | | | ----------------------------- | ------------------------------------------------------------------ | | "Properties" | the list of available properties | | "PropertyCanonicalNames" | the standard names of available properties | | "SampleEntities" | a sample list of available entities (typically of length 10) | | "SampleEntityClasses" | a sample list of available entity classes (typically of length 10) | | "EntityCount" | number of entities available | | "Entities" | the list of available entities | | "EntityCanonicalNames" | the standard names of available entities | | "EntityClasses" | the list of available entity classes | | "EntityClassCanonicalNames" | the standard names of available entity classes | | "PropertyClasses" | the list of available property classes | | "PropertyClassCanonicalNames" | the standard names of available property classes | | "PropertyCount" | number of properties available | * The following annotations can be used in the third argument of ``EntityValue["Planet", property, annotation]`` : | | | | --- | --- | | "Source" | source information for the property | | "Date" | the date associated with the entity-property value (if any) | | "EntityAssociation" | an association of entities and entity-property values | | "PropertyAssociation" | an association of properties and entity-property values | | "EntityPropertyAssociation" | an association in which the specified entities are keys, and values are a nested association of properties and entity-property values | | "PropertyEntityAssociation" | an association in which the specified properties are keys, and values are a nested association of entities and entity-property values | | "Dataset" | a dataset in which the specified entities are keys, and values are an association of property names and entity-property values | * The following annotations can be used in the second argument of ``EntityValue[property, annotation]`` : | | | | ------------------------ | --------------------------------------------------------------- | | "Qualifiers" | the list of possible qualifiers for the property | | "QualifierValues" | the list of possible values that can be given to each qualifier | | "DefaultQualifierValues" | the list of default values for the property's qualifiers | | "Description" | a brief textual description of the property | | "Definition" | a detailed textual definition of the property | | "PhysicalQuantity" | the physical quantity associated with the entity-property value | | "Unit" | the unit associated with the entity-property value | * A qualifier value of ``Automatic`` indicates that an applicable format of values can be used; e.g. for the ``"Date"`` qualifier, this includes a proper date or date span. --- ## Examples (36) ### Basic Examples (10) Use ctrl+= for discovery: ```wl In[1]:= [image] Out[1]= Entity["Planet", "Jupiter"] ``` --- Find the mass of a planet: ```wl In[1]:= Entity["Planet", "Mars"]["Mass"] Out[1]= Quantity[6.41711966293481651961856`4.031999499102814*^23, "Kilograms"] ``` --- Get a list of the planets: ```wl In[1]:= EntityValue["Planet", "Entities"] Out[1]= {Entity["Planet", "Mercury"], Entity["Planet", "Venus"], Entity["Planet", "Earth"], Entity["Planet", "Mars"], Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"], Entity["Planet", "Uranus"], Entity["Planet", "Neptune"]} ``` --- Retrieve a dataset of all available properties for an entity: ```wl In[1]:= \[FreeformPrompt]["Mars"]["Dataset"] Out[1]= Dataset[<>] ``` --- Find the three most massive planets: ```wl In[1]:= EntityClass["Planet", {"Mass" -> TakeLargest[3]}]//EntityList Out[1]= {Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"], Entity["Planet", "Neptune"]} ``` --- Find the radius of each planet: ```wl In[1]:= EntityValue["Planet", "Radius", "EntityAssociation"] Out[1]= <|Entity["Planet", "Mercury"] -> Quantity[1515.9592977014236856756`3.086306430528143, "Miles"], Entity["Planet", "Venus"] -> Quantity[3760.4141811818977173308`3.4808545713497088, "Miles"], Entity["Planet", "Earth"] -> Quantity[3958.7613130981732958 ... y[36225.9405074365704286964`4.012340888092028, "Miles"], Entity["Planet", "Uranus"] -> Quantity[15760.2517961769937989827`3.650884370322422, "Miles"], Entity["Planet", "Neptune"] -> Quantity[15300.0228664598743338901`3.0831323847966323, "Miles"]|> ``` --- Find the next rise time for a planet at your location and time: ```wl In[1]:= Entity["Planet", "Venus"]["RiseTime"] Out[1]= DateObject[{2025, 6, 27, 2, 54}, "Minute", "Gregorian", -5.] ``` --- Get a list of classes of planets: ```wl In[1]:= EntityValue["Planet", "EntityClasses"] Out[1]= {EntityClass["Planet", All], EntityClass["Planet", "InnerPlanet"], EntityClass["Planet", "NakedEyePlanet"], EntityClass["Planet", "OuterPlanet"], EntityClass["Planet", "PlanetKnownBeforeHerschel"], EntityClass["Planet", "PlanetKnownToAncientPeople"], EntityClass["Planet", "RetrogradeRotationPlanet"], EntityClass["Planet", "RingedPlanet"]} ``` --- Find the planets in a given class: ```wl In[1]:= EntityClass["Planet", "OuterPlanet"]["Entities"] Out[1]= {Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"], Entity["Planet", "Uranus"], Entity["Planet", "Neptune"]} ``` --- Make a graphic of solar system orbit paths: ```wl In[1]:= Graphics3D[EntityValue["Planet", "OrbitPath"]] Out[1]= [image] ``` ### Scope (18) The solar system planets: ```wl In[1]:= EntityValue["Planet", "Entities"] Out[1]= {Entity["Planet", "Mercury"], Entity["Planet", "Venus"], Entity["Planet", "Earth"], Entity["Planet", "Mars"], Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"], Entity["Planet", "Uranus"], Entity["Planet", "Neptune"]} ``` --- Orbital eccentricity for each planet: ```wl In[1]:= EntityValue["Planet", "Eccentricity"] Out[1]= {0.20563069, 0.00677323, 0.016710220, 0.093412330, 0.048392660, 0.0541506, 0.047167710, 0.00858587} ``` --- Orbital periods in sidereal years: ```wl In[1]:= EntityValue["Planet", "OrbitPeriod"] Out[1]= {Quantity[87.9692571749999999962`7., "Days"], Quantity[224.7007992150000000002`8., "Days"], Quantity[365.2563553499999999961`8., "Days"], Quantity[1.8808476`8., "JulianYears"], Quantity[11.862615`8., "JulianYears"], Quantity[29.447498`8., "JulianYears"], Quantity[84.016846`8., "JulianYears"], Quantity[164.79132`8., "JulianYears"]} ``` --- Rules for the orbital elements of Earth: ```wl In[1]:= Entity["Planet", "Earth"]["OrbitRules"] Out[1]= {"SemimajorAxis" -> 1.4959788714676577601`8.99956592252068*^11, "Eccentricity" -> 0.016710220, "Inclination" -> 0.00005, "PeriapsisArgument" -> 114.20783, "AscendingNodeLongitude" -> -11.26064, "PeriapsisLongitude" -> 102.94719, "Periapsis" -> 1.470980735410081476044021778`8.931464628195394*^11, "Apoapsis" -> 1.520977007525234044155978222`8.933541465906867*^11} ``` --- Obliquity of each planet: ```wl In[1]:= EntityValue["Planet", "Obliquity"] Out[1]= {Quantity[0.01`1., "AngularDegrees"], Quantity[177.36`5., "AngularDegrees"], Quantity[23.45`4., "AngularDegrees"], Quantity[25.19`4., "AngularDegrees"], Quantity[3.13`3., "AngularDegrees"], Quantity[26.73`4., "AngularDegrees"], Quantity[97.77`4., "AngularDegrees"], Quantity[28.32`4., "AngularDegrees"]} ``` --- Albedo of each planet: ```wl In[1]:= EntityValue["Planet", "Albedo"] Out[1]= {0.142, 0.689, 0.434, 0.170, 0.538, 0.499, 0.488, 0.442} ``` --- An image of Jupiter: ```wl In[1]:= Entity["Planet", "Jupiter"]["Image"] Out[1]= [image] ``` --- The known satellites of Neptune: ```wl In[1]:= Entity["Planet", "Neptune"]["Satellites"] Out[1]= {Entity["PlanetaryMoon", "Naiad"], Entity["PlanetaryMoon", "Thalassa"], Entity["PlanetaryMoon", "Despina"], Entity["PlanetaryMoon", "Galatea"], Entity["PlanetaryMoon", "Larissa"], Entity["PlanetaryMoon", "S2004N1"], Entity["PlanetaryMoon", "Proteus"], Entity["PlanetaryMoon", "Triton"], Entity["PlanetaryMoon", "Nereid"], Entity["PlanetaryMoon", "Halimede"], Entity["PlanetaryMoon", "Sao"], Entity["PlanetaryMoon", "Laomedeia"], Entity["PlanetaryMoon", "Psamathe"], Entity["PlanetaryMoon", "Neso"]} ``` Diameter of each satellite: ```wl In[2]:= EntityValue[%, "Diameter"] Out[2]= {Quantity[36.0395291497653702378`2., "Miles"], Quantity[49.7096953789867175694`2., "Miles"], Quantity[91.9629364511254275034`2., "Miles"], Quantity[98.1766483734987671996`2., "Miles"], Quantity[120.5460112940427901058`2., "Miles"], Quantity[12.4274 ... 96699`3., "Miles"], Quantity[37.282271534240038177`2., "Miles"], Quantity[24.8548476894933587847`2., "Miles"], Quantity[24.8548476894933587847`2., "Miles"], Quantity[24.8548476894933587847`2., "Miles"], Quantity[37.282271534240038177`2., "Miles"]} ``` Orbit semimajor axis: ```wl In[3]:= EntityValue[%%, "SemimajorAxis"] Out[3]= {Quantity[29966.86848802990535274`5., "Miles"], Quantity[31115.162451284498528593`5., "Miles"], Quantity[32638.1432434582040881254`5., "Miles"], Quantity[38495.8094726795514197089`5., "Miles"], Quantity[45700.6084466714387974231`5., "Miles"], Quant ... 6741430048`5.*^6, "Miles"], Quantity[1.39323848723455022667621093`5.*^7, "Miles"], Quantity[1.46463403722261989978525411`5.*^7, "Miles"], Quantity[2.90149278215223097112860892`5.*^7, "Miles"], Quantity[3.00681519923645907897876402`5.*^7, "Miles"]} ``` --- Number of known satellites for each planet: ```wl In[1]:= Length /@ EntityValue["Planet", "Satellites"] Out[1]= {0, 0, 1, 2, 95, 274, 27, 14} ``` --- Compute positions for Venus in the morning sky for 2009: ```wl In[1]:= positions = Transpose[{ QuantityMagnitude[EntityValue[Entity["Planet", "Venus"], Table[EntityProperty["Planet", "Azimuth", {"Date" -> DateObject[DateList[{2009, 4, i, 5}]], "Location" -> GeoPosition[{40.1, -88.2}]}], {i, 14, 190, 2}]], "AngularDegrees"], QuantityMagnitude[EntityValue[Entity["Planet", "Venus"], Table[EntityProperty["Planet", "Altitude", {"Date" -> DateObject[DateList[{2009, 4, i, 5}]], "Location" -> GeoPosition[{40.1, -88.2}]}], {i, 14, 190, 2}]], "AngularDegrees"]}]; In[2]:= Graphics[Point[positions], Frame -> True, FrameLabel -> {"azimuth", "altitude"}] Out[2]= [image] ``` #### Implicit Entity Classes (1) Represent all of the planets with fewer than 15 moons: ```wl In[1]:= EntityClass["Planet", {"MoonCount" -> LessThan[15]}]; ``` Get a list of all the planets: ```wl In[2]:= EntityList[%] Out[2]= {Entity["Planet", "Neptune"], Entity["Planet", "Mars"], Entity["Planet", "Earth"], Entity["Planet", "Mercury"], Entity["Planet", "Venus"]} ``` #### Property Classes (1) Represent equatorial coordinates properties associated with planets: ```wl In[1]:= EntityPropertyClass["Planet", "EquatorialCoordinates"] Out[1]= EntityPropertyClass["Planet", "EquatorialCoordinates"] ``` Get a list of available property classes for planets: ```wl In[2]:= EntityValue["Planet", "PropertyClasses"] Out[2]= {EntityPropertyClass["Planet", "Atmosphere"], EntityPropertyClass["Planet", "DiscoveryCircumstances"], EntityPropertyClass["Planet", "EquatorialCoordinates"], EntityPropertyClass["Planet", "GalacticCoordinates"], EntityPropertyClass["Planet", "Geoc ... rtyClass["Planet", "HorizonCoordinates"], EntityPropertyClass["Planet", "LocationProperties"], EntityPropertyClass["Planet", "MapProperties"], EntityPropertyClass["Planet", "OrbitalProperties"], EntityPropertyClass["Planet", "PhysicalProperties"]} ``` Find the list of properties included in a property class: ```wl In[3]:= EntityPropertyClass["Planet", "EquatorialCoordinates"]["Properties"] Out[3]= {EntityProperty["Planet", "RightAscension"], EntityProperty["Planet", "Declination"]} ``` Obtain the property values for the properties in a property class for an entity: ```wl In[4]:= EntityValue[Entity["Planet", "Neptune"], EntityPropertyClass["Planet", "EquatorialCoordinates"]] Out[4]= {Quantity[MixedMagnitude[{10, 1.106}], MixedUnit[{"MinutesOfRightAscension", "SecondsOfRightAscension"}]], Quantity[MixedMagnitude[{-21, -10.46}], MixedUnit[{"Arcminutes", "Arcseconds"}]]} ``` #### Qualifiers (5) Some properties accept qualifiers: ```wl In[1]:= EntityValue[EntityProperty["Planet", "Constellation"], "Qualifiers"] Out[1]= {"Date"} In[2]:= EntityValue[EntityProperty["Planet", "RiseTime"], "Qualifiers"] Out[2]= {"Date", "Location"} ``` The ``"Location"`` qualifier, which specifies the location of the observer, can accept an explicit ``GeoPosition``, location-based ``Entity`` objects or queries that evaluate to one of these: ```wl In[3]:= EntityValue[Entity["Planet", "Mars"], EntityProperty["Planet", "RiseTime", {"Location" -> #}]& /@ {GeoPosition[{40.1, -88.2}], \[FreeformPrompt]["Joplin"], \[FreeformPrompt]["capital city of Iowa"]}] Out[3]= {DateObject[{2025, 6, 26, 10, 23}, "Minute", "Gregorian", -5.], DateObject[{2025, 6, 26, 10, 53}, "Minute", "Gregorian", -5.], DateObject[{2025, 6, 26, 10, 43}, "Minute", "Gregorian", -5.]} ``` ##### Dates (4) Date qualifiers can accept an explicit ``DateObject`` or queries that evaluate to a ``DateObject`` : ```wl In[1]:= EntityValue[Entity["Planet", "Mars"], EntityProperty["Planet", "DistanceFromEarth", {"Date" -> #}]& /@ {DateObject[{2014, 4, 9, 22, 0, 0}, "Instant", "Gregorian", -5.], \[FreeformPrompt]["birth date of Michael Jackson"]}] Out[1]= {Quantity[0.6195628053718316, "AstronomicalUnit"], Quantity[0.7588483830462895, "AstronomicalUnit"]} ``` Date qualifiers can also be specified using ``Dated`` : ```wl In[2]:= EntityValue[Entity["Planet", "Mars"], Dated["DistanceFromEarth", #]& /@ {DateObject[{2014, 4, 9, 22, 0, 0}, "Instant", "Gregorian", -5.], \[FreeformPrompt]["birth date of Michael Jackson"]}] Out[2]= {Quantity[0.6195628053718316, "AstronomicalUnit"], Quantity[0.7588483830462895, "AstronomicalUnit"]} ``` --- Compute the ecliptic path for a planet over the course of a year: ```wl In[1]:= eclipticPath[planets_] := Point /@ (Transpose[{-QuantityMagnitude[EntityValue[#, Table[EntityProperty["Planet", "RightAscension", {"Date" -> DateObject[DateList[{2008, 1, i}]]}], {i, 1, 365.25, 10}]], "HoursOfRightAscension"], QuantityMagnitude[EntityValue[#, Table[EntityProperty["Planet", "Declination", {"Date" -> DateObject[DateList[{2008, 1, i}]]}], {i, 1, 365.25, 10}]], "AngularDegrees"]}]& /@ planets); ``` The paths for the visible planets: ```wl In[2]:= Graphics[{ColorData[1][1], eclipticPath[{Entity["Planet", "Mercury"], Entity["Planet", "Venus"], Entity["Planet", "Mars"], Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"]}]}, PlotRange -> {{-24, 0}, {-90, 90}}, AspectRatio -> .5, Frame -> True, FrameTicks -> {Table[{-i, i^"h"}, {i, 0, 24, 4}], Automatic}] Out[2]= [image] ``` --- The distance from Earth to the visible planets over a year: ```wl In[1]:= dists = EntityValue[{Entity["Planet", "Mercury"], Entity["Planet", "Venus"], Entity["Planet", "Mars"], Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"]}, Table[EntityProperty["Planet", "DistanceFromEarth", {"Date" -> date}], {date, DateRange[{2008, 1, 1}, {2008, 12, 31}, "Week"]}], "EntityAssociation"]; In[2]:= DateListPlot[dists, {{2008, 1, 1}, {2008, 12, 31}}] Out[2]= [image] ``` --- The apparent magnitude of the visible planets as viewed from Earth over a year: ```wl In[1]:= mags = EntityValue[{Entity["Planet", "Mercury"], Entity["Planet", "Venus"], Entity["Planet", "Mars"], Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"]}, Table[EntityProperty["Planet", "ApparentMagnitude", {"Date" -> date}], {date, DateRange[{2008, 1, 1}, {2008, 12, 31}, "Week"]}], "EntityAssociation"]; In[2]:= DateListPlot[mags, {{2008, 1, 1}, {2008, 12, 31}}, ScalingFunctions -> "Reverse"] Out[2]= [image] ``` #### Geo Computation (1) Create maps of planets: ```wl In[1]:= GeoGraphics[GeoModel -> Entity["Planet", "Mars"], GeoRange -> All] Out[1]= [image] ``` ### Applications (2) Make a table of densities of planets: ```wl In[1]:= Text[Grid[EntityValue["Planet", {"Name", "Density"}], Frame -> All, Background -> LightYellow]] Out[1]= Text[Grid[{{"Mercury", Quantity[5.427`4., "Grams"/"Centimeters"^3]}, {"Venus", Quantity[5.243`4., "Grams"/"Centimeters"^3]}, {"Earth", Quantity[5.515`4., "Grams"/"Centimeters"^3]}, {"Mars", Quantity[3.934`5., "Grams"/"Centimeters"^3]}, ... rs"^3]}, {"Saturn", Quantity[0.6871`4., "Grams"/"Centimeters"^3]}, {"Uranus", Quantity[1.27`4., "Grams"/"Centimeters"^3]}, {"Neptune", Quantity[1.638`4., "Grams"/"Centimeters"^3]}}, Frame -> All, Background -> RGBColor[1, 1, 0.85]]] ``` --- Log-log plot of orbital period versus distance for the planets, illustrating Kepler's third law: ```wl In[1]:= ListLogLogPlot[EntityValue["Planet", {"OrbitPeriod", "SemimajorAxis"}], AxesLabel -> Automatic] Out[1]= [image] ``` ### Relations to Other Entity Types (3) ``"Planet"`` entities have natural satellites from the ``"PlanetaryMoon"`` domain: ```wl In[1]:= Entity["Planet", "Uranus"]["Satellites"] Out[1]= {Entity["PlanetaryMoon", "Cordelia"], Entity["PlanetaryMoon", "Ophelia"], Entity["PlanetaryMoon", "Bianca"], Entity["PlanetaryMoon", "Cressida"], Entity["PlanetaryMoon", "Desdemona"], Entity["PlanetaryMoon", "Juliet"], Entity["PlanetaryMoon", "Port ... anetaryMoon", "Stephano"], Entity["PlanetaryMoon", "Trinculo"], Entity["PlanetaryMoon", "Sycorax"], Entity["PlanetaryMoon", "Margaret"], Entity["PlanetaryMoon", "Prospero"], Entity["PlanetaryMoon", "Setebos"], Entity["PlanetaryMoon", "Ferdinand"]} ``` --- Atmospheric composition is specified using ``"Chemical"`` entities: ```wl In[1]:= Entity["Planet", "Mars"]["AtmosphericComposition"] Out[1]= <|Entity["Chemical", "CarbonDioxide"] -> Quantity[95.319999999999999998`4., "VolumePercent"], Entity["Chemical", "MolecularNitrogen"] -> Quantity[2.700000000000000002`2., "VolumePercent"], Entity["Chemical", "Argon"] -> Quantity[1.60000000000000000 ... ePercent"], Entity["Chemical", "Neon"] -> Quantity[0.0002500000000000007`2., "VolumePercent"], Entity["Chemical", "Krypton"] -> Quantity[0.0000300000000000007`1., "VolumePercent"], Entity["Chemical", "Xenon"] -> Quantity[8.*^-6, "VolumePercent"]|> ``` --- ``"Planet"`` entities can be combined with ``"SolarSystemFeature"`` entities to create maps with labeled features: ```wl In[1]:= coords = Entity["SolarSystemFeature", "OlympusMonsMars"]["Position"]; In[2]:= GeoGraphics[{GeoStyling[Red, Opacity[.3]], Red, Point[coords], White, Text[Entity["SolarSystemFeature", "OlympusMonsMars"]["Name"], coords, {0, 2}]}, GeoRange -> All, GeoGridLines -> True, Frame -> True, GeoModel -> Entity["Planet", "Mars"], GeoZoomLevel -> 1] Out[2]= [image] ``` ### Possible Issues (2) Pluto is not included in the list of solar system planets: ```wl In[1]:= EntityValue["Planet", "Entities"] Out[1]= {Entity["Planet", "Mercury"], Entity["Planet", "Venus"], Entity["Planet", "Earth"], Entity["Planet", "Mars"], Entity["Planet", "Jupiter"], Entity["Planet", "Saturn"], Entity["Planet", "Uranus"], Entity["Planet", "Neptune"]} ``` It is now considered a "dwarf planet": ```wl In[2]:= Entity["MinorPlanet", "Pluto"]["ObjectType"] Out[2]= "DwarfPlanet" ``` --- Some information is unknown, for a variety of different reasons: ```wl In[1]:= EntityValue["Planet", "DiscoveryYear"] Out[1]= {Missing["Prehistoric"], Missing["Prehistoric"], Missing["Prehistoric"], Missing["Prehistoric"], Missing["Prehistoric"], Missing["Prehistoric"], DateObject[{1781}, "Year", "Gregorian", -5.], DateObject[{1846}, "Year", "Gregorian", -5.]} ``` ### Neat Examples (1) Plot the orbit period versus the orbit semimajor axis for planets in the solar system: ```wl In[1]:= ListLogLogPlot[Tooltip[{##2}, #1]&@@@EntityValue[EntityClass["Planet", All], {"Name", "SemimajorAxis", "OrbitPeriod"}]] Out[1]= [image] ``` ## See Also * [`EntityValue`](https://reference.wolfram.com/language/ref/EntityValue.en.md) * [`PlanetaryMoon`](https://reference.wolfram.com/language/ref/entity/PlanetaryMoon.en.md) * [`MinorPlanet`](https://reference.wolfram.com/language/ref/entity/MinorPlanet.en.md) * [`Exoplanet`](https://reference.wolfram.com/language/ref/entity/Exoplanet.en.md) * [`Comet`](https://reference.wolfram.com/language/ref/entity/Comet.en.md) * [`SolarSystemFeature`](https://reference.wolfram.com/language/ref/entity/SolarSystemFeature.en.md) * [`MeteorShower`](https://reference.wolfram.com/language/ref/entity/MeteorShower.en.md) * [`Planet`](https://reference.wolfram.com/language/ref/interpreter/Planet.en.md) * [`ComputedPlanet`](https://reference.wolfram.com/language/ref/interpreter/ComputedPlanet.en.md) * [`Planet`](https://reference.wolfram.com/language/ref/textcontent/Planet.en.md) ## Related Guides * [Entity Types](https://reference.wolfram.com/language/guide/EntityTypes.en.md) ## Related Links * [Planet Source Information](http://www.wolfram.com/knowledgebase/source-information/?page=PlanetData) ## History * [Introduced in 2014 (10.0)](https://reference.wolfram.com/language/guide/SummaryOfNewFeaturesIn100.en.md)