The week of July 1-7 takes us from Lunar Day 25 to Day 2. This week we will highlight the moon crater Pythagoras, located to the West of Mare Frigoris in the NW quadrant of the Field Map at C3. It is viewable on Tuesday night.

PythagorasPythagoras: [NW/C3] There is only a brief period during each lunation when Pythagoras is visible. It is a complex moon crater with two central mountain peaks, terraced walls, and internal features. It is an impressive 80 miles in diameter (compare to Copernicus at 58 miles.) Its spectacular rim mountains rise to an imposing three miles above its floor1! The central mountain peaks alone attain a height of one mile. Although it is close to the northwest limb and is substantially foreshortened, it is worth a visit. Try to catch it when the libration is favorable, as it will be on Monday night.


On Monday, Mars is 1.4° south of the Moon.

1 To put this into perspective, these peaks would soar 7,000 feet higher than Colorado’s 14ers!

Field Map of the Moon, the very finest Moon map available for use at the telescope. It is available for $10.95 at and on Amazon. All features mentioned in this blog will be keyed to the grid on the Field Map and will look like this: Plato: [NW/D9]

Courtesy of Gray Photography of Corpus Christi, Texas
Lunar photos: NASA / USGS / BMDO / LROC / ASU / DLR / LOLA / Moon Globe. Used by permission

Andrew Planck
Pythagoras: Complex Moon Crater with Two Central Mountain Peaks

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