The Wikipedia article on the moon says ithat "Ptolemy (90–168 AD)" calculated the distance of the moon as 59 times the Earth's radius and a diameter, which is about the modern value. But Wikipedia doesn't say how Ptolemy did that. An article at http://www.eso.org tells how to calculate the moon's distance on the basis of the moon's apparent position, from two different locations on earth, during a solar eclipse, but it seems likely Ptolemy did not use this method. Does anyone know how Ptolemy, some 2,000 years ago, might have calculated the distance to the moon? Just wondering . . .