A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2022 Sep 19, 01:30 -0700
I’m pleased someone agrees with me. Just back from a week’s e-biking in the Peak District (Derbyshire/Staffordshire) I felt far too lazy to look at the formula. However, I did look at GHA Moon in my newly downloaded lunar distance tables. Living at 000° 32'W I had no conscience about swapping GHA for LHA. E.g.:
16th September 2022 0400hrs UTC GHA Moon = 353° 28.5’ = 353.474°
17th September 2022 0400hrs UTC GHA Moon = 341° 30.1’ = 341.502°
That’s 11.973° short. Therefore 353.474° occurs approximately 12/15 = 12*4/60 hrs later = 48 minutes later.
I.e., the Moon's LHA cycle is nominally 24 hours 50 minutes, not 12 hours 50 minutes.
Daisy, Daisy, give me your answer do
I'm half-crazy all for the love of you
It won't be a stylish marriage
I can't afford a carriage
But you'll look sweet upon the seat
Of a bicycle built for two