API Reference

getMoonPhase

MoonPhaseResult getMoonPhase([DateTime? date])

Returns the moon phase for the given UTC date, or the current moment if date is null.

Field	Type	Description
`phase`	`MoonPhaseName`	Enum: `newMoon`, `waxingCrescent`, `firstQuarter`, `waxingGibbous`, `fullMoon`, `waningGibbous`, `lastQuarter`, `waningCrescent`
`phaseName`	`String`	Human-readable phase name
`phaseSymbol`	`String`	Moon emoji for the current phase
`illumination`	`double`	Percent illuminated (0-100)
`age`	`double`	Hours since the last new moon
`elongationDeg`	`double`	Moon-Sun elongation in degrees
`isWaxing`	`bool`	True when illumination is increasing
`nextNewMoon`	`DateTime`	Next new moon (UTC)
`nextFullMoon`	`DateTime`	Next full moon (UTC)
`prevNewMoon`	`DateTime`	Previous new moon (UTC)

MoonPosition getMoonPosition(
  DateTime? date,
  double lat,
  double lon, {
  double elevation = 0,
})

Computes the topocentric position of the moon for an observer at the given location. Applies atmospheric refraction to the altitude.

Parameter	Type	Default	Description
`date`	`DateTime?`	now	UTC date and time
`lat`	`double`	required	Observer latitude (-90 to 90)
`lon`	`double`	required	Observer longitude (-180 to 180)
`elevation`	`double`	0	Observer elevation in meters

Field	Type	Description
`azimuth`	`double`	Degrees from North, clockwise (0-360)
`altitude`	`double`	Degrees above horizon (refraction applied)
`distance`	`double`	Earth-Moon distance in km
`parallacticAngle`	`double`	Parallactic angle in radians

MoonIlluminationResult getMoonIllumination([DateTime? date])

Returns illumination data for the given UTC date, or now if null.

Field	Type	Description
`fraction`	`double`	Illuminated fraction (0-1)
`phase`	`double`	Phase cycle position (0=new, 0.25=first quarter, 0.5=full, 0.75=last quarter)
`angle`	`double`	Bright limb position angle in radians
`isWaxing`	`bool`	True when waxing

MoonVisibilityEstimate getMoonVisibilityEstimate(
  DateTime? date,
  double lat,
  double lon, {
  double elevation = 0,
})

Estimates lunar crescent visibility using the Odeh (2006) criterion. Pass a post-sunset time for meaningful results.

Parameter	Type	Default	Description
`date`	`DateTime?`	now	UTC date and time (use post-sunset)
`lat`	`double`	required	Observer latitude
`lon`	`double`	required	Observer longitude
`elevation`	`double`	0	Observer elevation in meters

Field	Type	Description
`v`	`double`	Odeh V parameter
`zone`	`OdehZone`	Visibility zone (a, b, c, or d)
`description`	`String`	Human-readable zone description
`isVisibleNakedEye`	`bool`	True for zone A
`isVisibleWithOpticalAid`	`bool`	True for zones A and B
`arcl`	`double`	Sun-Moon elongation in degrees
`arcv`	`double`	Arc of vision in degrees
`w`	`double`	Crescent width in arc minutes
`moonAboveHorizon`	`bool`	True if the moon is above the horizon at the given time

Zone	V threshold	Meaning
A	V >= 5.65	Visible with naked eye
B	V >= 2.00	Visible with optical aid, may be naked-eye visible
C	V >= -0.96	Visible with optical aid only
D	V < -0.96	Not visible even with optical aid

MoonSnapshot getMoon(
  DateTime? date,
  double lat,
  double lon, {
  double elevation = 0,
})

Convenience function that runs all four computations in one call.