Hi John Yesterday I realised that the ecliptic moves during a single day. Sounds stupid, but I've never realised that before. I thouhgt that it changes only during long periods over months and seasons etc. But over a single day?! I know the change of the seasons and the motion of the sun over a year etc., but I really cannot explain this motion over 24 hours. When I animate the daily motion it looks to me as if it was an exaggerated motion of the earth's precession. I just don't get it. The seasonal changes etc. are no problem, but these not obvious short-term-things seem to be.
But this should not affect the creation of a local horizon in CdC. When I write down the time when the moon just rises above or sets below the horizon, and subtract the moon's radius from the local altitude, then I should get the horizon altitude at the moon's azimut at that time and I can simulate the horizon altitude there. But my problem is that the setting moon was displayed much closer to the mathematical horizon compared to the already simulated rising-horizon-mountain in the south-east (it was as if the western south-mountain is half or a third as high as the south-eastern one) - although the two mountain's altitude would not have created such an obvious difference...they're pretty much of the same height, and the observing position was also the same. It's really strange. And all because of this strange daily-eliptic-precession. I don't get it. Thanks for your help! Luzius
