Earth

public class Earth : Object, PlanetaryBase, PlanetaryOrbits

Undocumented

  • Undocumented

    Declaration

    Swift

    public static var averageColor: Color { get }
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  • Equatorial radius of the Eart. Source: Wikipedia.

    Declaration

    Swift

    public static let equatorialRadius: Meter
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  • Polar radius of the Eart. Source: Wikipedia.

    Declaration

    Swift

    public static let polarRadius: Meter
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  • Computes the julian day of the equinox for the given year

    Declaration

    Swift

    public func equinox(of equinoxType: EarthEquinoxType) -> JulianDay

    Parameters

    equinoxType

    if yes, means the spring equinox for the northern hemisphere. if flase, it is the autumn equinox of the northern hemisphere.

    Return Value

    A julian day of the TT time of the equinox.

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  • Computes the julian day of the solstice for the given year

    Declaration

    Swift

    public func solstice(of solsticeType: EarthSolsticeType) -> JulianDay

    Parameters

    solsticeType

    if true, means the summer solstice in the northern hemisphere, if false, means the winter solstice in the norther hemisphere.

    Return Value

    A julian day of the TT time of the solstice.

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  • Computes the length of a given season.

    Declaration

    Swift

    public func lengthOfSeason(_ season: Season, northernHemisphere: Bool) -> Day

    Parameters

    season

    The season to compute the length of.
    northernHemisphere

    A flag indicating which hemisphere to consider

    Return Value

    A length in (Julian) Days.

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  • Returns the times of twilights (including transit time).

    Declaration

    Swift

    public func twilights(forSunAltitude sunAltitude: Degree, coordinates: GeographicCoordinates) -> (rise: JulianDay?, transit: JulianDay?, set: JulianDay?, error: CelestialBodyTransitError?)

    Parameters

    sunAltitude

    The sun altitude to consider. See TwilightSunAltitude for known values.
    coordinates

    The geographic coordinates for which to compute the twilights.

    Return Value

    The rise, transit and set times, in Julian Day, and an error, if relevant.

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  • Returns the rise, transit and set times for a given planet, as seen from Earth. That is, the equivalent of Sun twilights, but for planets.

    Declaration

    Swift

    public func riseTransitSetTimes(for planetaryObject: KPCPlanetaryObject, geographicCoordinates: GeographicCoordinates) -> (riseTime: JulianDay?, transitTime: JulianDay?, setTime: JulianDay?, error: CelestialBodyTransitError?)

    Parameters

    planet

    The considered planet. Cannot be the Earth.
    coordinates

    The geographic coordinates for which to compute the twilights.

    Return Value

    The rise, transit and set times, in Julian Day, and an error, if relevant.

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  • The heliocentric coordinates of the Earth. That is, its apparent position on the celestial sphere, as as it would be seen by an observer at rest at the barycenter of the solar system, and referred to the instantaneous equator, ecliptic and equinox. See AA pp.217 and following.

    Declaration

    Swift

    public var heliocentricEclipticCoordinates: EclipticCoordinates { get }
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  • The nutation is a periodic oscillation of the rotational axis of the Earth around its “mean” position It is due principally to the action of the Moon. It can be decomposed into components parallel and perpendicular to the ecliptic. Here it is that component along the ecliptic.

    Declaration

    Swift

    public var nutationInLongitude: ArcMinute { get }
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  • The nutation is a periodic oscillation of the rotational axis of the Earth around its “mean” position It is due principally to the action of the Moon. It can be decomposed into components parallel and perpendicular to the ecliptic. Here it is that component perpendicular to the ecliptic.

    Declaration

    Swift

    public var nutationInObliquity: ArcMinute { get }
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  • AA p.147: The obliquity of the ecliptic, or inclination of the Earth’s axis of rotation, is the angle between the equator and the ecliptic. One distinguishes the mean and the true obliquity, being the angles which the ecliptic makes with the mean and with the true (instantaneous) equator. In other words, the adjective “mean” indicates that the correction for nutation is not taken into account. AA p.92: If the apparent right ascension and declination are used, that is affected by the aberration and the nutation, the true obliquity should be used.

    Declaration

    Swift

    public func obliquityOfEcliptic(mean: Bool = true) -> Degree
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