Skip to the content

Wakusei Planets documentation

Wakusei Planets API: every export

Every export of every entry point, each with its own page. This page keeps the addresses the old one-page reference had.

@johnmorrisdotca/wakusei-planets/element

setThreeLoaderfunction

Where three.js comes from, if a page wants to hand it over itself (before the first element connects).

TEXTURE_BASEconstant

The default home of the surface pictures: the files of this exact version on jsDelivr.

TEXTURE_FAR_BASEconstant

Where the sharpest surface pictures are: the files of this exact version in the repository, on jsDelivr's GitHub address.

WakuseiBodyclass

The <wakusei-body> custom element: a body of the solar system, drawn in a look.

WakuseiStatetype

What the element is doing: line (an SVG), loading (waiting for three.js or a picture), still (a picture of the 3D look, nothing running), live (drawing), lost (the GPU took the context; it comes back by itself) or unavailable (no WebGL: the line drawing is shown).

@johnmorrisdotca/wakusei-planets/portrait

PortraitStatetype

What the element is doing: line (an SVG), loading, still, live, lost or unavailable (no WebGL: the line drawing is shown).

setThreeLoaderfunction

Where three.js comes from, if a page wants to hand it over itself (before the first element connects).

WakuseiPortraitclass

The <wakusei-portrait> custom element: a scene of bodies arranged on one picture.

@johnmorrisdotca/wakusei-planets/space

blendfunction

A frame between two others, t from 0 to 1.

compressfunction

The same direction at a compressed distance from the Earth: the Moon is 10 Earth radii away, and a body k times further than the Moon is k^0.25 times as far here.

createTrackfunction

Answers for any moment from two real ones: at(ms) works out a frame only when ms leaves the span the last two answers cover, and then looks stepMs ahead, so playing time at a steady rate costs one pair of lookups every stepMs and every draw in between is arithmetic.

EARTH_RADIUS_KMconstant

The Earth's equatorial radius in kilometres (IAU), the unit of the scene's distances.

frameAtfunction

The state of the sky at ms: the Sun, the Moon and eight planets as seen from the Earth's centre, worked out by this package's own models in a fraction of a millisecond.

groundDirectionfunction

The unit direction, in the scene's axes, of a longitude and latitude on the Earth as the stars see it at ms: the camera fixed to the stars looks at the same place on the ground only at that moment, and the Earth turns away under it as time runs.

MOON_COMPRESSEDconstant

The Moon's distance in a compressed view, in Earth radii (the true one is about 60).

placeAroundfunction

A place helio astronomical units from the Sun (a planet, or a point on its orbit), round the Sun at sun.

placeMoonfunction

The Moon, from the Earth's centre.

placeSunfunction

The Sun, from the Earth's centre: in a compressed view always 44 Earth radii away, in its real direction.

planetOrbitfunction

The path a planet takes round the Sun, as count + 1 points round one trip from where the planet is at ms, from the Sun, in astronomical units and the scene's axes.

radiusInfunction

A body's radius in Earth radii: the real one, or one large enough to see in a compressed view.

RIDE_FOVconstant

The field of view, in degrees, of a camera riding along at zoom 1.

RideInputtype

What ridePose is asked: the camera's place from the centre of the body it goes round and its way of travel (any length), that body's radius in the unit of the place, where it looks, and the shared controls' yaw, tilt and zoom.

RideLooktype

Where a riding camera looks: down straight at the centre of the body it goes round (the ground goes by under the camera), or horizon tipped forward along the way it is going until the horizon is a little above the middle of the view.

ridePosefunction

The camera of a body-borne view: at position, looking at the body it goes round (a Moon over the Earth, a moon over Jupiter, a spacecraft over Mars: any centre, by radius), with the way it is going at the top of the picture.

RidePosetype

The camera ridePose works out: where it is, which way it looks, which way is up in the picture, its field of view in degrees, and how big the body looks from there (its angular radius in degrees).

ScaleModetype

The scale the space view is drawn in: compressed squeezes the distances so the Moon, the Sun and Neptune fit one view, and true keeps the real ones.

SPACE_PLANETSconstant

The planets the space view places, nearest the Sun first (the Earth is the middle of the view).

SpaceFrametype

Where everything is at one moment: positions in astronomical units from the Earth's centre, in J2000 equatorial axes with y north.

SpaceVec3type

A position or direction as [x, y, z] in the scene's axes: J2000 equatorial, x to the vernal equinox, y north.

SUN_COMPRESSEDconstant

The Sun's distance from the Earth in a compressed view, in Earth radii (the true one is about 23,500).

truePositionfunction

A place in astronomical units from the Earth's centre, at true distance, in Earth radii.

@johnmorrisdotca/wakusei-planets/space/element

BodyInfotype

What a page can tell a reader about a body now.

RideOptionstype

How a ride along is done: view from (the default) puts the camera at the target looking at the body it goes round, follow keeps it a distance from the target looking at it (distanceKm, 3000 by default, for a point of your own; a body or a moon is kept at the distance the zoom says); look down (the default) or horizon is where a camera at the target points; around is the body a point of your own goes round (the Earth by default); smooth (the default) glides from the old camera to the new one in about a second and a bit, and jumps instead for a reader who asked for reduced motion.

RidePointtype

Any moving point a camera can ride: where it is and which way it goes at a moment, from the centre of the body it goes round, in kilometres and kilometres a second, in the scene's axes (J2000 equatorial, y north).

RideTargettype

What a camera can ride along with: a body of the view (moon, mars, ...

Ridingtype

What the camera is riding along with now: the target, the body it goes round, how (from or follow), where it looks, and the distance kept for a point.

setThreeLoaderfunction

Where three.js comes from, if a page wants to hand it over itself (before the first element connects).

SPACE_BODIESconstant

The eleven bodies the space view places, names and lets a reader choose: the Earth, the Sun, the Moon, the seven other planets and Pluto.

SpaceBodytype

One of the bodies in SPACE_BODIES, by the package's usual lower-case name.

SpaceLighttype

How the Earth is lit: sun is the true light; lit is daylight from the camera's side, so a view of the night side is never black.

SpacePresettype

A named distance for zoomFor: the Earth, the Moon, the Sun, the inner planets, the whole solar system, or a planet with its nearer moons (jupiter-moons).

SpaceStatetype

What the space view is doing: loading, live, unavailable (no WebGL), lost (the GPU took the context; it comes back by itself).

WakuseiSpaceclass

The <wakusei-space> custom element: the Earth, the Moon, the Sun and the planets where they are at a date and time, drawn with three.js through the shared renderer.

@johnmorrisdotca/wakusei-planets/time

B1950_JDconstant

The Julian date of the Besselian epoch B1950.0, 1950 January 0.923 (Meeus).

Calendartype

Which calendar: gregorian and julian are used for every year (the proleptic calendars), and auto follows history: the Julian calendar to 1582-10-04 and the Gregorian from 1582-10-15.

convertTimeScalefunction

A moment on one time scale as the same moment on another, in milliseconds since 1970 read on the target scale's own clock.

coordinatedMarsTimefunction

Coordinated Mars Time: the mean solar time on Mars's prime meridian, in hours from 0 up to 24 (a Martian hour is 1/24 of a sol).

dayOfWeekfunction

The day of the week of a moment in UTC: 0 Sunday to 6 Saturday.

dayOfYearfunction

The day of the year of a moment in UTC: 1 on 1 January.

daysInMonthfunction

The number of days in a month; October 1582 has 21 in the auto calendar, the ten days of the switch being left out.

deltaTfunction

Delta T, terrestrial time minus universal time (UT1), in seconds.

equationOfTheEquinoxesfunction

The equation of the equinoxes in degrees: the nutation in longitude times the cosine of the obliquity, what apparent sidereal time has over mean (about 1 second of time at most).

fromCalendarfunction

A date and time of day in UTC as a moment, in milliseconds since 1970.

fromJulianDatefunction

The time, in milliseconds since 1970, of a Julian date.

fromJulianDayAndMillisecondsfunction

A time from a Julian day and the milliseconds into it, with no digit lost: fromJulianDayAndMilliseconds(toJulianDay(t), toMillisecondsInJulianDay(t)) is t.

greenwichApparentSiderealTimefunction

The Greenwich apparent sidereal time in degrees, 0 to 360: the mean time with the equation of the equinoxes added, which is what the hour angle of a body is measured against.

J2000_JDconstant

The Julian date of J2000.0, 2000-01-01 12:00 TT: the epoch of the planets' theories.

J2000_MSconstant

J2000.0, 2000-01-01 12:00, as milliseconds since 1970 counted on a clock that reads TT: a terrestrial time is this far from it.

julianfunction

A time as a string of its Julian date with six decimals, as the julian package gives it (a tenth of a second).

julianCenturiesfunction

Julian centuries (36,525 days) from J2000.0: the time argument of most theories.

julianMillenniafunction

Julian millennia (365,250 days) from J2000.0, in terrestrial time unless scale says UTC: the time argument of the VSOP87 series.

localSiderealTimefunction

The local sidereal time in degrees, 0 to 360, at a longitude east of Greenwich (west negative): the right ascension on the meridian.

marsLocalMeanSolarTimefunction

The local mean solar time on Mars at a longitude east of its prime meridian, in hours from 0 up to 24.

marsSolDatefunction

The Mars Sol Date: the count of Martian days, as the Julian date counts Earth's.

modifiedJulianDatefunction

The modified Julian date: the Julian date less 2,400,000.5, so a day starts at midnight and the numbers are shorter.

taiMinusUtcfunction

TAI minus UTC in seconds: the leap seconds from 1972 (10 then, 37 since 2017), and before 1972 delta T less 32.184, which is how far the atomic scale would have been from the Earth's turn.

tdbMinusTtfunction

TDB minus TT in seconds: a term that follows the Earth round the Sun and is never more than 1.7 milliseconds (Meeus's two terms, 0.001657 sin g and 0.000014 sin 2g, good to about 30 microseconds).

TimeScaletype

A time scale: utc (the clock), ut1 (the Earth's turn, within 0.9 s of UTC), tai (atomic time), gps (TAI less 19 s), tt (terrestrial time, TAI plus 32.184 s) and tdb (barycentric dynamical time, TT plus a few milliseconds that follow the year).

toCalendarfunction

A moment as a date and time of day in UTC, in the Gregorian or the Julian calendar.

toDatefunction

The Date of a Julian date (a number, or the string julian gives), rounded to the millisecond.

toJulianDatefunction

A time as a Julian date: the days since noon on 1 January 4713 BC (Julian calendar), as a number.

toTerrestrialTimefunction

A moment in UTC as the same moment in terrestrial time, on the same scale of milliseconds since 1970.

ttMinusUtcfunction

Terrestrial time minus the clock's time, in seconds, at a moment given in UTC: 69.184 from the last leap second in 2017 on (until another is added), exact from 1972, and delta T before.

Whentype

A moment: a Date or a number of milliseconds since 1970 (UTC, as JavaScript counts).

@johnmorrisdotca/wakusei-planets/stars

blackBodyColourfunction

The colour of a black body at a temperature, as a #rrggbb string, for drawing a star.

Startype

One star, as the Yale Bright Star Catalogue gives it.

starByHrfunction

A star by its Bright Star Catalogue number.

starByNamefunction

A star by its common name (Sirius) or its designation (α CMa, 9 CMa), ignoring case.

starColourfunction

The colour to draw a star: from its B-V index, or a plain white where the catalogue has none.

starPositionfunction

Where a star is at a moment: its J2000 position carried forward (or back) by its proper motion in a straight line.

starsfunction

The stars to a magnitude, brightest first.

starTemperatureKfunction

The surface temperature a colour index implies, in kelvin, by Ballesteros's relation between B-V and a black body.

@johnmorrisdotca/wakusei-planets/nearest

Approachtype

The closest two bodies come in a span: the moment of the minimum and the separation then.

closestApproachfunction

When two bodies come closest in a span, and how close: the span is scanned in coarse steps (the fastest body goes round forty times in the step, at most two days), then the smallest minimum is narrowed to about a second of time by golden-section search.

conjunctionsfunction

The close approaches of every pair of bodies in a span, soonest first: each pair's separation is scanned in coarse steps (the fastest body goes round forty times in the step, at most two days), and every minimum inside the span that is within within is narrowed to about a second of time.

distancefunction

The distance between two bodies on a date: the straight line between their centres at that instant, in kilometres and astronomical units, with no light time.

Distancetype

The distance between two bodies at one instant: their centres, in the Sun's frame, with no light time.

DistanceAttype

The least or the greatest distance of a pair over a span, and when.

distanceRangefunction

The least and the greatest distance between two bodies over a span, each with its moment: the span is scanned in coarse steps (as closestApproach does) and each turning point is narrowed to about a second of time by golden-section search, the greatest on the negated distance.

DistanceRangetype

Where a pair is nearest and farthest over a span.

nearestfunction

The bodies nearest to a body on a date, nearest first: by the angle between them in the sky of an observer, or by the distance between them in space.

NearestOptionstype

The options of nearest, within, closestApproach and conjunctions that mean the same in each.

SkyNeighbourtype

A body near the target in the sky: its angle from the target in degrees (0 to 180) and how far that angle may be off, in arc-seconds.

SpaceNeighbourtype

A body near the target in space: the distance between their centres, and how far that may be off.

Viewpointtype

Where the sky is seen from: a body's centre ("mars" for the sky of Mars), or a place on the Earth, whose parallax counts (the Moon is up to a degree different from there than from the Earth's centre).

withinfunction

Every body inside a radius of a body on a date, nearest first: nearest with no limit on how many.

@johnmorrisdotca/wakusei-planets/spacecraft

loadSpacecraftfunction

Load the fitted paths of some spacecraft (or all of them), each a table of its own that nothing else imports: about 6 kB gzipped for the Voyagers, the Pioneers, New Horizons and JWST, and more for the craft that orbited a planet.

SPACECRAFTconstant

The ten craft and their facts, keyed by id.

SPACECRAFT_IDSconstant

The ten craft: voyager1, voyager2, newhorizons, pioneer10, pioneer11, cassini, galileo, juno, parker and webb.

spacecraftEarthDistancefunction

A craft's distance from the Earth's centre at a moment, in kilometres: the craft's path from Horizons and the Earth from VSOP87B (a few thousand kilometres at most), both for the same instant, with no allowance for the light's travel.

spacecraftErrorKmfunction

The worst error of a craft's loaded path against Horizons, in kilometres, as measured when it was made: on samples held back from the fit and on fresh samples at random times.

SpacecraftIdtype

The name of a craft: voyager1, cassini, webb...

spacecraftLightTimefunction

How long a radio signal takes from the Earth to a craft (or back), at a moment, in seconds: the distance from the Earth over the speed of light.

spacecraftPositionfunction

Where a craft is at a moment: x, y, z in kilometres from the Sun, in the J2000 ecliptic frame (the same axes as heliocentric, which is in astronomical units).

spacecraftSpeedfunction

A craft's speed relative to the Sun at a moment, in kilometres a second.

spacecraftVelocityfunction

A craft's velocity relative to the Sun at a moment, in kilometres a second, in the same frame as spacecraftPosition.

Whentype

A moment: a Date or a number of milliseconds since 1970 (UTC, as JavaScript counts).

@johnmorrisdotca/wakusei-planets/suncalc

addTimefunction

Add a time to the ones getTimes gives: when the Sun reaches an altitude in degrees, going up under the morning name and going down under the evening name.

getMoonPositionfunction

The Moon's place in the sky from a place on the Earth.

getMoonTimesfunction

The Moon's rise, set and transits over a day at a place.

getPositionfunction

The Sun's place in the sky from a place on the Earth.

getTimesfunction

The Sun's times for a day at a place.

MoonIlluminationtype

The Moon's illumination: the lit fraction 0 to 1, the phase 0 to 1 (0 new, 0.25 first quarter, 0.5 full, 0.75 last quarter), the position angle of the bright limb in degrees eastward from north, and whether it is waxing.

MoonPositiontype

The Moon in a place's sky: the Position, the Moon's distance in kilometres and the parallactic angle in degrees.

MoonTimestype

The Moon's rise, set and transits over a day.

Positiontype

Where a body is in a place's sky: the azimuth in degrees clockwise from north (0 north, 90 east, 180 south, 270 west) and the apparent altitude (refraction included) in degrees.

SunTimeNametype

The names of the Sun's times that getTimes gives.

SunTimestype

The Sun's times for a day: each a Date or null when the Sun does not reach that height that day, solarNoon and nadir always there, and alwaysUp or alwaysDown when the Sun stays above or below the sunrise height all day.

timesconstant

The altitudes of the Sun's times in degrees: the morning name when it rises through the angle, the evening name when it sets through it.

@johnmorrisdotca/wakusei-planets/suncalc/legacy

addTimefunction

Add a time to the ones getTimes gives: when the Sun reaches an altitude in degrees.

getMoonPositionfunction

The Moon's place in the sky, as suncalc 1 gave it: the altitude includes refraction.

getMoonTimesfunction

The Moon's rise and set over the 24 hours from midnight of the moment's day, in the machine's zone or, with inUTC, in UTC.

getPositionfunction

The Sun's place in the sky, as suncalc 1 gave it: the altitude has no refraction in it.

getTimesfunction

The Sun's times for the solar day nearest a moment, as suncalc 1 gave them: every time a Date, invalid when it does not happen.

LegacyMoonIlluminationtype

The Moon's illumination in suncalc 1's terms: the lit fraction, the phase 0 to 1, and the bright limb's angle in radians, negative while the Moon waxes and positive while it wanes.

LegacyMoonPositiontype

The Moon in a place's sky: the LegacyPosition, the distance in kilometres and the parallactic angle in radians.

LegacyMoonTimestype

The Moon's rise and set; alwaysUp or alwaysDown is true when the Moon never rises or sets in the day.

LegacyPositiontype

Where a body is: the azimuth in radians from south toward west (0 south, a quarter turn west) and the altitude in radians.

LegacySunTimestype

The Sun's times with every one a Date: an invalid Date (NaN) when the Sun does not reach that height that day.

timesconstant

The times suncalc 1 gives, as [altitude in degrees, morning name, evening name].

@johnmorrisdotca/wakusei-planets/tables

@johnmorrisdotca/wakusei-planets/tables/ceres

@johnmorrisdotca/wakusei-planets/tables/dwarfs

@johnmorrisdotca/wakusei-planets/tables/vsop

@johnmorrisdotca/wakusei-planets/tables/galilean

@johnmorrisdotca/wakusei-planets/tables/saturn-moons

@johnmorrisdotca/wakusei-planets/look

Atmospheretype

A rim of air: the colour it scatters (0 to 1 each), how strong it is and how thin the rim is.

BodyLooktype

What a body looks like in three.js: the shader code of its surface, how it glows, its atmosphere and its painted map.

lookOffunction

The look registered for a body, or undefined when its entry point has not been imported.

PaintedMaptype

The painted look of a body: a surface map in the package's textures folder, as widths from the smallest up.

registerLookfunction

Teach the package how to draw a body in three.js.

@johnmorrisdotca/wakusei-planets/painter

createPainterfunction

Make a painter that takes its pictures from the given folders (jsDelivr's copy of this version by default).

LOOKSconstant

The looks the painter draws: realistic (shaded from the body's real colours and features) and painted (a public-domain surface map, with the shaded look until it arrives).

moonOffsetfunction

Where a moon is from its planet's centre, in planet radii, in the scene's axes (x to the vernal equinox, y north).

MoonSitetype

One moon of a planet at a time: where it is from the planet's centre and how big it is, both in radii of the planet, in the scene's axes.

orientationfunction

The north pole and the prime meridian of a body at a time, as unit vectors in the scene's axes (x to the vernal equinox, y north).

PaintContexttype

What the caller gives the painter when it makes a body.

painterconstant

The painter with its default pictures: pass it to chikyu-earth's setBodyPainter.

PainterLooktype

One of the looks in LOOKS: realistic or painted.

PainterOptionstype

Where the pictures are, if not on jsDelivr: a folder address that ends in a slash.

PaintInfotype

What the caller tells a painted body at each draw: the direction to the Sun (a unit vector in the scene's axes), the time, and how many CSS pixels across its radius the body is on the screen.

Paintingtype

One body made by the painter: an object of radius 1 at the origin for the caller to move and scale.

WakuseiPaintertype

A painter: makes the bodies as three.js objects (make) and tells where a planet's moons are (moons).

@johnmorrisdotca/wakusei-planets/all

@johnmorrisdotca/wakusei-planets/sun

@johnmorrisdotca/wakusei-planets/mercury

@johnmorrisdotca/wakusei-planets/venus

@johnmorrisdotca/wakusei-planets/mars

@johnmorrisdotca/wakusei-planets/jupiter

@johnmorrisdotca/wakusei-planets/saturn

@johnmorrisdotca/wakusei-planets/uranus

@johnmorrisdotca/wakusei-planets/neptune

@johnmorrisdotca/wakusei-planets/pluto

@johnmorrisdotca/wakusei-planets/dwarfs

@johnmorrisdotca/wakusei-planets/moons-earth

@johnmorrisdotca/wakusei-planets/moons-mars

@johnmorrisdotca/wakusei-planets/moons-jupiter

@johnmorrisdotca/wakusei-planets/moons-saturn

@johnmorrisdotca/wakusei-planets/moons-uranus

@johnmorrisdotca/wakusei-planets/moons-neptune

@johnmorrisdotca/wakusei-planets/moons-pluto

@johnmorrisdotca/wakusei-planets/moons-dwarf

@johnmorrisdotca/wakusei-planets/earth

@johnmorrisdotca/wakusei-planets/coordinates

CartesianAutype

Right-handed Cartesian components in AU: x at longitude zero, y at 90 degrees, z north.

CoordinateObservertype

Earth observer: degrees north/east; optional metres above the WGS 84 ellipsoid.

CoordinateOrigintype

Origin is preserved by every rotation; no observer translation is performed.

eclipticToEquatorialfunction

Rotate a mean ecliptic direction into the matching mean equatorial frame.

equatorialToHorizontalfunction

Rotate a mean equatorial-of-date direction to an observer's horizon (Meeus 12.4, 13.5–6).

meanObliquityfunction

Mean obliquity in degrees: IAU 1980 (Meeus 22.2), evaluated in TT.

SphericalAutype

Spherical coordinates: longitude [0,360), latitude [-90,90], radius in AU.

sphericalToCartesianfunction

Convert spherical to Cartesian, preserving origin, frame, epoch and geometric corrections.

@johnmorrisdotca/wakusei-planets

addBodyfunction

Add a body to a scene (once), in its place in the order of the sky for an automatic layout, or at the front and to the right of the others for a manual one.

apparentfunction

How a body looks from the Earth at a time, from its real pole, rotation and the Sun's direction.

Apparenttype

What the sky shows of a body at a time: its pose, the latitude the viewer sees it from (how open its rings are), the longitude at the middle of the disc, the phase and the size.

BODIESconstant

Every body's facts, by name: sizes, flattening, axial tilt, poles and rotation from the IAU and NASA.

BODY_IDSconstant

Every body's name: the Sun, the planets outward, the dwarf planets, then the moons of each.

BodyFactstype

The facts of one body: its radius, flattening, axial tilt, pole, prime meridian, rotation, colour, rings and the features a line drawing shows.

BodyIdtype

The name of a body: sun, a planet, a dwarf planet or a moon.

defaultPortraitfunction

An empty scene with the usual settings: an automatic row, readable sizes, the stars behind, the Sun upper left.

drawnTiltfunction

The tilt a drawing shows for a body: its obliquity, turned past 120 degrees to the other side (Venus is nearly upside down, so it is drawn nearly upright).

DWARF_IDSconstant

The dwarf planets besides Pluto, nearest the Sun first (by the size of their orbits).

DwarfIdtype

The name of a dwarf planet besides Pluto: ceres, eris, haumea...

EMBED_KINDSconstant

The ways embedCode writes a body into a page.

embedCodefunction

The text that puts a body in a page, for one way of making the page.

embedCreditfunction

The credits that travel with a picture of a body: the line and illustrated looks are drawn from numbers, and realistic and painted use the surface maps.

EmbedKindtype

One of the ways in EMBED_KINDS.

EmbedOptionstype

What the reader chose: the body, how it is drawn, and whether it is a portrait or the sky at a date.

EmbedSettingstype

Where the embed code points: the package's version on jsDelivr, and the published demo, where embed.html is.

encodeScenefunction

The scene as one short piece of text that is safe in an address: fields joined by ~, each name:value, then one body_x_y_r_spin_tilt_pitch_turn for each body, back to front.

Featuretype

A thing a line drawing shows on a body's surface, placed by longitude and latitude in degrees (angular sizes in degrees): a circle, an oval, a band of latitude or a line.

heliocentricfunction

A planet's or dwarf planet's position in the Sun's frame (J2000 ecliptic, astronomical units) at a time: Mercury to Neptune from the VSOP87B series, and Pluto and the other dwarf planets from tables fitted to Horizons (each within a few arc-seconds or better, see the accuracy guide; outside a table's years a dwarf planet falls back to the osculating elements of one epoch from JPL's Small-Body Database).

heliocentricModelfunction

The theory that heliocentric(planet, ms) answers with, given the tables loaded now: VSOP87B for Mercury to Neptune, a fitted Chebyshev table where one covers the moment, else osculating elements (a dwarf planet) or JPL's approximate elements (Pluto outside its table).

HostIdtype

A body a moon can go round: a planet, Pluto or another dwarf planet.

JOURNEY_STOPSconstant

Every body, in the same order as BODY_IDS: the Sun, the planets, the dwarf planets, then the moons.

layoutPortraitfunction

Where every body is and how big, and the camera that holds them.

LineOptionstype

Options for lineSvg: the size, a pose (tilt, pitch, phase, spin, a time or a pose), moons, range, fill, the language and the colours.

lineSvgfunction

A body as a line drawing, as an SVG string: the outline (squeezed by its flattening and leaning at its axial tilt), bands and features, rings with their gaps, and the dark side dashed off.

Looktype

How a body is drawn: line (an outline drawing), realistic and painted (a real surface map; painted is the same maps), or illustrated (shaded from the numbers, not a default).

meanSunAufunction

Mean distance from the Sun, in astronomical units: a planet's semi-major axis at J2000, or a dwarf planet's semi-major axis at the epoch of its elements.

mixfunction

Mix two #rrggbb colours: t is how much of b (0 to 1).

moonGeocentricfunction

The Moon's position from the Earth's centre (J2000 mean ecliptic and equinox, kilometres), from the lunar solution ELP2000-82B (Chapront-Touze and Chapront, IMCCE) cut to its 540 largest terms and run in terrestrial time: within a few arc-seconds of Horizons from 1800 to 2200.

MoonIdtype

The name of a moon the package draws, such as moon, io or titan.

MoonPlacetype

One moon, placed in a planet's system: in planet radii, x to the right, y up, z toward the viewer, with its distance from the planet and its phase angle.

MOONS_OFconstant

The moons the package draws, by planet or dwarf planet.

orbitPathfunction

The path one moon follows round its planet over one trip, as the Earth sees it at time: x, y, z in planet radii, in the viewer's frame at that moment.

PlacedItemtype

A body of a scene as the layout puts it: its place and size now (stored, or worked out by an automatic layout), and how far its picture reaches past the disc.

PLANET_IDSconstant

The planets and the dwarf planet Pluto, nearest the Sun first.

PlanetIdtype

The name of a planet or of Pluto: mercury to pluto.

portraitfunction

A pose from a tilt, a pitch, a phase and a spin: the body as a portrait, with the Sun a little above the left.

Portraittype

A portrait scene: the bodies, back to front, and how they are arranged, sized, lit and drawn.

PORTRAIT_PRESETSconstant

Ready-made scenes to start from: a family photo of the Sun and the planets, the gas giants to scale, Jupiter and the Galileans, the Earth and the Moon to scale (size and distance), Mars and its moons at their true distance, and the inner planets round the Sun.

portraitCodefunction

The text that puts a portrait scene in a page, for each way a page is made, as embedCode does for a single body.

PortraitEmbedtype

A scene of the portrait builder to put in a page: the scene as the builder writes it in its address, how wide the picture is, and the look to draw it in if not the scene's own.

PortraitItemtype

One body in the scene: which body, where it is and how big, how it is turned and how fast it turns by itself.

PortraitLayouttype

What a layout works out for a scene: every body placed, and the camera that holds them (its centre and half-height, in the scene's units).

PortraitPresettype

A ready-made scene with its name in English and Japanese.

Posetype

The way a body is turned toward the viewer, in the viewer's frame (x to the right, y up, z toward the viewer), as unit vectors: its north pole, the direction of longitude 0 and the Sun's direction.

RingBandtype

One band of a ring system, in kilometres from the planet's centre: how much light it stops (alpha, 0 to 1) and how bright it is (tone, 0 dark, 1 bright).

ringReachfunction

The ring system's outer edge in body radii, or 1 for a body with no rings.

ringStripfunction

The strip of a body's rings, made from its ring bands: where each band is it stops light and has its tone, with fine ringlets in it and soft edges.

RingStriptype

The strip of a body's rings: RGBA bytes width pixels across, and the inner and outer radii in body radii.

stopPlaceAufunction

Where a body is in the Sun's frame at an instant, in astronomical units.

systemfunction

A planet and its moons as the Earth sees them at a time: each moon's place in planet radii, in the viewer's frame (x right, y up, z toward the viewer).

Systemtype

A planet's own pose and its moons as the Earth sees them at a time, nearest first.