The crater floor has a complex of central peaks, with much additional detail, particularly toward the south. The ejecta blanket has overridden much of the original surface just outside the crater, and extends for hundreds of kilometers in a bright ray structure that is prominent at high sun angles.
Copernicus is visible to the naked eye, from Earth, as an albedo feature, when well illuminated. It is a "landmark" feature, easily recognized and useful for orientation.
May, 1997: While perusing the rich field around Copernicus, appreciating the little craterlet lines and fine rille structures shot throughout, we started noticing the domes as showing particularly well... especially the group of five near Hortensius, one of which is a double dome with only one peak "cratered." We were easily able to spot the central craters in all of them (save the one that has none), so we went shopping -- and found another group showing well almost directly to the north.
In the process, we also noticed a few wrinkle ridges that seem to end in small craters, almost like a negative version of Rima Birt or Schroter's Valley. This may be coincidental, or it might be a feature of the Copernican topology. But another odd thing was these *enormous* domes in the area. One was a little north and west of Milchius, and shows well on the charts. The other, equally well defined, does not show on my charts: it was west and slightly north of Reinhold. This is interesting in that they are so low and usually (I presume) ill defined as to be a rare event; I wonder if anyone knows if the second large dome (probably about 25x35 miles) is charted anywhere? It was definitely pear shaped, with the narrow end to the south southwest.
The last weird feature of the night was a squarish island north of Copernicus, across the mountains, and directly west toward the terminator. It appears separated from the rest of the range, and distinctly square -- raised much like a dome, but peppered with all manner of blocks and marks as if it were somehow piled there as a rubbish heap. Odd, indeed.
A catena going out from Copernicus, and perpendicular to Rima Gay-Lussac, was easily seen, but only some of the craters could be resolved. Stadius was not easily distinguished, but the tiny craters in the area were quite evident.
Clavius showed lots of little craters in its interior. Longomontanus D looked like a single crater with an illuminated banana in the center. Only part of the inner rim could be seen.
|Chart 30||Moon-Lite Atlas for chart 31||Chart 32|