01 December 1972
Vol 178, Issue 4064

About The Cover

Lunar topography. The edge of the moon appears as the curved edge at the top of the photograph with the same direction. Lighter shades of gray indicate higher elevations. One of the interesting feactures is the height of the floor of the large crater Ptolemaeus at the top of map, higher than the large mare to the map, higher than the larger mare to the left. Other large creaters below Ptolemaeus are Alphonsus and Arzachel, with the smaller but very deep Alpetragius just to the left and below Alphonsus. See page 977.[Stanley H. Zisk, Haystack Observatory, Westford, Massachusetts]