If anyone is wondering about the somewhat polygonal shape of the lunar umbra, apparently it's not a rendering error, it really is a bit polygonal. The edges cor

If anyone is wondering about the somewhat polygonal shape of the lunar umbra, apparently it's not a rendering error, it really is a bit polygonal. The edges correspond to some lunar valleys, as this nasa link explains: http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4517&button=recent http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4517&button... The Earth relief has quite an impact on the umbra shape too, in some cases I would say it can change the diameter of the umbra by a few percent (check 00:26 in the nasa animation)