Diëteris
A diëteris or biëteris is the Greek name for the period over 2 tropical years where the Moon phase occurs around 8 years later.
It corresponds to 25 synodic months,
2.0213017935214 sidereal months, 27.129896020025 draconic months, 26.792841801954996 anomalistic months, and 738.264699074075 days.
It’s the result of intercalating 2 lunar years (which’s 24 synodic months, 1.9404497217805439 sidereal months, 26.044700179224 draconic months,
25.721128129876796, and 708.734111111112 days).
It approximates 2 synodic periods of Uranus, meaning 2 new/full moons in opposite/conjunction with Uranus occur a diëteris apart.
Though adding an extra synodic month forms a long diëteris, which is 28.1020710232132 sidereal months, 28.215091860826 draconic months, 27.864555474033196 anomalistic months, and 767.7952870370381 days, and is sometimes useful for calculating oppositions with Mars.
It corresponds to 25 synodic months,
2.0213017935214 sidereal months, 27.129896020025 draconic months, 26.792841801954996 anomalistic months, and 738.264699074075 days.
It’s the result of intercalating 2 lunar years (which’s 24 synodic months, 1.9404497217805439 sidereal months, 26.044700179224 draconic months,
25.721128129876796, and 708.734111111112 days).
It approximates 2 synodic periods of Uranus, meaning 2 new/full moons in opposite/conjunction with Uranus occur a diëteris apart.
Though adding an extra synodic month forms a long diëteris, which is 28.1020710232132 sidereal months, 28.215091860826 draconic months, 27.864555474033196 anomalistic months, and 767.7952870370381 days, and is sometimes useful for calculating oppositions with Mars.
Ben: The Moon is with Uranus in just about every diëteris.
Gregory: I see.
Ben: Because a diëteris compares to 2 synodic periods of Uranus.
Gregory: Interesting.
Ben: Yet the last full moon of 2022 went in front of Mars and that will happen again before my 30th birthday in 2025.
Gregory: That's cool.
Gregory: I see.
Ben: Because a diëteris compares to 2 synodic periods of Uranus.
Gregory: Interesting.
Ben: Yet the last full moon of 2022 went in front of Mars and that will happen again before my 30th birthday in 2025.
Gregory: That's cool.
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