Sub Lunar Point

This graphic originally surfaced with the presentation of Golden Ratios, Golden Rectangles - once again, too good to not eventually front a topic. 

The point on Earth where the Moon passes over during its travel is called the "sub lunar point (SLP)". Since the Earth rotates as the Moon travels, the Moon does describe a full circle around the Earth in about a day. The Nautical Almanac describes the position on Earth with the daily pages, and adds v and d corrections since the Earth rotates appreciably on top of the overall orbital motion.

When we tabulate the prediction for 1240 GMT, the SLP comes out to be far away from anything in the North Atlantic. If we adjust to go back to 0840 GMT (the actual Triton closest approach) we get an SLP that is callably "close" to Morocco. Since Roger is just poetically alluding to Morocco proximity, I THINK we can call this as predicted. So we are a little closer to ... having a clue.

Lots of fun things on this map. Western Sahara is described as "the last colony on Earth" - so most of Western Sahara (the part to the west of the giant "berm" barrier set up deep in the desert) counts as Morocco. Farther up on the Moroccan Atlantic coast is Sidi Ifni - a speck of Morocco that Spain used to claim as its own for decades after Moroccan independence. I still have Ifni stamps, since Spain used Ifni as a place to generate revenue by pushing out stamps that collectors "had to have" ... 

Some things don't change. Jack and Kasbah Kelly could have had a sequel AND a prequel, plenty of territory to cover.

Now, we need to look up the corresponding place on the Moon - the "sub earth point"? This looks to be a MUCH more obscure task - as we would expect from Roger.