
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2013 Apr 20, 22:45 -0700
Gary, you wrote:
"Didn't somebody post a long time ago that you couldn't see the moon rise or set due to absorption near the horizon causing the moon to dim out prior to actually being on the horizon?"
Sure. Marcel has frequently made that point. He's backed off on it a bit, if I recall, but it really is difficult to see the Moon LITERALLY on the sea horizon because of extinction. It's true that you can see the Full Moon right on the horizon when conditions are good, but Half Moon? Forget it. Extinction takes it out. I have seen the Full Moon right on the horizon only a handful of times ever.
This video and similar photos are different. A "hill" horizon, as I've recently called it, can be a degree or more above the true horizon, without being blatantly, obviously a hill. But that degree or so makes all the difference in the world. The refraction and the extinction (generally proportional to the refraction) are much smaller. I'm sure all of us have seen the Moon rise over a "hill" horizon.
-FER
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------