Comets in our solar system.

Entity["Comet",name] or

represents an entity of type "Comet".

[prop]

gives the value of a specified property.

[{prop1,}]

gives the value of a list of properties.

[prop,{qualivali,}]

gives the value of a specified property modified by qualifier rules quali->vali.

[Dated[prop,date]]

gives the value of a property associated with a particular date specification.

EntityClass["Comet",{propispeci,}]

represents a class of entities with values of propi defined by speci.

Sample Entities

Sample Entity Classes

Properties

  • Ageage
    AlphanumericNamealphanumeric name
    AlternateNamesalternate names
    Altitudealtitude
    Aphelionlargest distance from the Sun
    Apoapsislargest distance from orbit center
    ApoapsisTimenext apoapsis time
    ApoapsisTimeLastlast apoapsis time
    ApparentAltitudeapparent altitude
    ApparentMagnitudeapparent magnitude
    AscendingNodeLongitudelongitude of ascending node Ω
    AverageDistanceFromEarthaverage distance from Earth
    AverageOrbitDistanceaverage orbit distance
    AverageOrbitVelocityaverage orbit velocity
    AverageVelocityAroundSunaverage heliocentric velocity
    Azimuthazimuth
    BooleanRiseabove the horizon
    Classesclasses
    Constellationconstellation
    DailyTimeAboveHorizondaily time above horizon
    Declinationdeclination
    DestructionDatedestruction date
    Diameteraverage diameter
    DiscoveryYeardiscovery year
    DistanceFromEarthdistance from Earth
    DistanceFromSundistance from Sun
    EarthMOIDEarth minimum orbit intersection distance
    EccentricAnomalyeccentric anomaly
    Eccentricityorbital eccentricity
    EquatorialDiameterequatorial diameter
    EquatorialRadiusequatorial radius
    GalacticLatitudegalactic latitude
    GalacticLongitudegalactic longitude
    GravitationalConstantMassProductgravitational constant mass product
    GreenwichHourAngleGreenwich hour angle
    HeliocentricLatitudeheliocentric latitude
    HeliocentricLongitudeheliocentric longitude
    HelioCoordinatesheliocentric XYZ coordinates
    IAUNameIAU name
    Imageimage
    Inclinationorbital inclination
    LocalHourAnglelocal hour angle
    MajorAxisorbital major axis
    MaximalAltitudeTimenext maximum altitude time
    MeanAnomalymean anomaly
    MeanMotionmean motion
    MinorAxisorbital minor axis
    Namename
    NuclearMagnitudeParameternuclear magnitude parameter
    NuclearMagnitudeSlopeParameternuclear magnitude slope parameter
    ObjectTypeobject type
    OrbitCenterorbit center
    OrbitCircumferenceorbit circumference
    OrbitPathorbit path
    OrbitPeriodorbital period
    OrbitRulesorbit rules
    Periapsisnearest distance from orbit center
    PeriapsisArgumentargument of periapsis ω
    PeriapsisLongitudelongitude of periapsis ϖ
    PeriapsisTimenext periapsis time
    PeriapsisTimeLastlast periapsis time
    Perihelionnearest distance from the Sun
    PrimaryDesignationprimary designation
    Radiusaverage radius
    RetrogradeApparentMotionQueryapparent direction
    RightAscensionright ascension
    RiseTimenext rise
    RotationPeriodrotation period
    SemimajorAxisorbital semimajor axis
    SemiminorAxisorbital semiminor axis
    SetTimenext set
    Shapeshape
    SiderealHourAnglesidereal hour angle
    SolarDaysolar day
    SphereOfInfluenceRadiussphere of influence radius
    SurfaceAreasurface area
    TotalMagnitudeParametertotal magnitude parameter
    TotalMagnitudeSlopeParametertotal magnitude slope parameter
    TrueAnomalytrue anomaly
    Volumevolume

Details

  • "Comet" entities include a subset of modern and historical comets that have been observed.
  • "Comet" entity classes include groups based on orbit type, but also groups based on definitions such as "great comets".
  • Due to the fact that most comets have never been visited directly by spacecraft, most available data is focused on orbital parameters. Physical properties such as mass and radius are more sparse.
  • Some properties are available for the "Comet" entity type as a whole and can be given using the form EntityValue["Comet",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["Comet",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

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Basic Examples  (7)

Use for discovery:

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Find the current distance to a comet:

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Find the next periapsis time of a comet:

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Get a list of available classes of comets:

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Rank comets in a class by orbit period:

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Retrieve a dataset of all available properties for an entity:

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Find comets with the 3 least eccentric orbits:

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Scope  (3)

Neat Examples  (1)