Hiya Doug,

As stated, the info is from publications like 'Time Magazine' and 'National Geographics', both USA produced.I dont recall exactly which one it was, circa 1980 to 83, full featured article.

Axis tilt is from World news at the time, circa 1980 to 81.

Following this, sattelite nav became standard, no more navigating by the stars for big ships.