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Other Cycles of the Earth and of the Moon
Sideric day | Moon culmination | Sideric moon | Metonic Cycle
Saros period | Moon knot | Apsidis rotation
The Sideric Day of the Earth
Tone 194.71 Hz = G (a1 = 437.1 Hz / 440 Hz - 11.4 cent)
Tempo 91.3 bpm
Color red-orange
Explanation Duration of the true revolution of earth around its axis.The sideric day is about 4 minutes shorter than the average calender day.
tone sample MP3
Moon-culmination
Tone 187.61 Hz = F# (a1 = 446.2 Hz / 440 Hz + 24.2 cent)
Tempo 87.9 bpm
Color red
Explanation The time span for one passage of the moon from one south to the next one. Every day, the moon rises about 50 minutes later than the preceding day. The delay adds up to one day during a (tropical) month.
tone sample MP3
The Sideric Moon
Tone 227.43 Hz = A# (a1 = 429.3 Hz / 440 Hz - 42.5 cent)
Tempo 106.6 bpm
Color yellow (yellow)
Explanation The time span for one revolution of the moon around the earth, as measured against the celestial sphere. The sideric month is about two and a quarter days shorter than a synodic month.This is caused by the apparent course of the sun along the ecliptic. As the sun passes approximately one sign per month, the moon has to pass through 13 signs to "keep up with it".
tone sample MP3
Moon: Metonic cycle
Tone 229.22 Hz = A# (a1 = 432.7 Hz / 440 Hz - 28.9 cent)
Tempo 107.45 bpm
Color yellow (yellow)
Explanation The time span of about 19 year, after which the sun and the moon have the same aspects on the same day. The metonic cycle is the basis of combined soli-lunar calendars.
tone sample MP3
Moon: Saros Period
Tone 241.56 Hz = B (a1 = 430.4 Hz / 440 Hz - 38.2 cent)
Tempo 113.2 bpm
Color yellow-green
Explanation The time span of approximately 18 years and 10 days, after which eclipses of the same type repeat themselves.
tone sample MP3
Moon: Apsidis rotation
Tone 246.04 Hz = B (a1 = 438.4 Hz / 440 Hz - 6.3 cent)
Tempo 115.3 bpm
Color yellow-green
Explanation The duration of the movement of one axis of the elliptical orbit of the moon around the ecliptic. The two extreme points of the bigger axis are called perigee (the point where the moon is closest to the earth) and apogee (the point where the moon is most distant from the earth). One such revolution takes about 8.85 years.
tone sample MP3
Moon knot
Tone 234.16 Hz = A# (a1 = 442 Hz / 440 Hz + 8 cent)
Tempo 109.8 bpm
Color yellow (yellow)
Explanation The duration of the path of the nodes along the ecliptic, about 18,6 years. The nodes are the intersection of the orbit of the moon with the ecliptic. If the moon moves along the ecliptic from South to North, it crosses the North node, which is also called the "head of the dragon". If it moves from North to South, it crosses the South node, which is also called the "tail of the dragon".
tone sample MP3