crater copernicus at 885x

That's what I saw last night, and it was amazing.

Seeing was similar to the previous night, with a 6-8 second trough where fine detail was fuzzed out, then a 2-3 second crest of very sharp and steady views.  885x is 77x per inch of aperture of the telescope (a 12.5-inch masked down to 11.5-inches) -- well beyond the commonly held maximum useful magnification figure of 50x inch.  So I guess I can stop worrying about the mirror's quality.

Copernicus was huge, and it took on a weight and body I'd never imagined.  Usually it appears flat, and only interesting for its terraces in the crater and the finely granulated particles of its ejecta fanning out across much of the lunar surface.  But last night, at 70.84% full, waxing, Copernicus looked like the stump of an ancient tree whose center had rotted out, but whose gnarled, many branched roots still gripped the lunar surface.  The crater walls were tall, with shear cliffs at each terrace level.  The rim was bright and curved sinuously.  The depth and physical presence of the thing was astonishing.  Nearby Eratosthenes too was bulky, as if built up out of clay.

None of my moon books give a photo showing what I saw.  The Kaguya Lunar Atlas has a very nice image on plate 49, which show the ribbon like crater rim, but it doesn't show the height of the thing.  The Hatfield Photographic Lunar Atlas plate 5b is pretty good, but the depth is only hinted, and it does not show the ropey hills and ridges which make the outer sides of the crater, which I can only liken to buttress roots around a large tree's trunk.  I like plate 5b because it shows my Lunar Eagle feature to the east of Eratosthenes, on the near edge of the Montes Apenninus.  I think Rukl plate 31 comes the closest, though this is a drawing.  There's not much sense of the crater's depth but the ropey, veiny ridges radiating around the crater are more distinct.  It's only a little larger than the field of view I had, too.

A terrific view.  Next time the seeing is as steady as that, I'll be sure to pump up the magnification again.