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Avani Soares

Location of Photo:

Canoas, Brazil

Date/Time of photo:

June 02-2023; 02:22 TU


C14 Edge + ASI 290MM + IR 685


Pythagoras is a magnificent example of a lunar crater. It is 129 km in diameter and is very close to the northwest branch of the Moon and, as a consequence, appears greatly shortened to us on Earth, changing shape due to the effects of lunar libration. The crater rim is surrounded by sloping walls that rise gently above their surroundings. The terrace appears to descend to a relatively flat floor approximately 3 miles below. If the Moon were rotated 65° to the south, Pythagoras would replace Copernicus as the most impressive visible crater. Aside from the obvious central mountain complex that sits at the center of the crater, the floor shows little detail until the lighting becomes oblique, at which time a large number of hills are visible which are visible in the photo to the left of the central peaks. Surprisingly, the highest central peaks, rising about 3 km from the bottom of the floor, are higher than some of the surrounding terrain, in violation of Mädler's Rule. This rule has never been confirmed with modern data, but it seems certain. Unlike Copernicus, Pythagoras does not appear to have withheld his rays when viewed at full moon. Its greatest age was recognized during the Apollo era when it was mapped to be the same age as the ancient Imbrium lavas. One thing ancient astronomers didn't know is that the central peaks of Pythagoras, like those of Anaxagoras, Philolaus and Carpenter, contain pure anorthosite, remnants of ocean magma. Like Moretus near the south pole, Pythagoras offers an oblique view of what large fresh complex craters really look like. If we were looking a billion years ago, when the two polar craters were cool with the rays very evident, Copernicus would still be hot with molten lava on the ground, and Tycho in this case would still be 900 million years in the future.