It was semi-clear after a week and a half of clouds and rain. Since the moon was gibbous and wiping out my favorite galaxies, I decided to look at this annoying, huge and bright orb which shines with cold light.
The ray systems of Copernicus and Tycho were very prominent. I studied the terminator, which crossed beyond the west side of Mare Humorum (selenographic [moon-based] coordinates -- it's actually on the east side of the moon when you look at it in the sky), and the western part of Oceanus Procellarum.
I saw lots of interesting stuff which I neglected to identify. I think next time I'll take Rukl's Atlas of the Moon out with me.
The little hills at 51W 3S (Rukl chart 40) were nicely situated on the terminator and showing great relief. One of them was a double peak, which cast a long twin peaked shadow. I'm not certain of this identification (it might have been 49W 4.5S), but if someone can tell me what the selenographic longitude of the terminator was at this time last night, I can probably find it.
I noticed that the interior walls of Aristarchus were terraced. (I can't believe I didn't look at the detailed stuff in the area of Vallis Schroeteri -- maybe it was mostly in shadow. Yet another reason to bring out Rukl with me!)
I did most of my exploring at 413x.
Looking at the moon with a motorized equatorial mount is indeed a completely different experience from looking at it with a hand-pushed dob. It's a pleasant experience. Because the image is not flying through the field of view, the power can be raised to the limit of the optics or atmosphere, and the formations can be studied and appreciated in a much more relaxed manner.
I decided to try to see how far I could jack up the power. The seeing was not perfect, but it wasn't too bad. The images were a little wavy, but not badly fuzzed out.
When I first went to 413x early in my session, I could sense that was the limit. The scope was not in equilibrium. Later on, I put in the barlow, and went up to 620x, and then 827x. I don't think the image at 827x showed any more detail than it did at 620x (the blurs just became bigger), but I was astonished that there was a usable image at all. I think 620x showed more detail than 413x, but I'm not certain.
When slewing the scope at high power, the view was reminiscent of the old Apollo films showing the moon moving rapidly by as the LM approached. The only thing missing was the LM.
At this power, the defects of my eyepieces became glaring -- there were spots all over the place, which rotated when I rotated the eyepieces. Different eyepieces had different spots and smudges.
I gotta get new eyepieces!
--------------------------------------------------------------------- Date: Apr 7, 1998 9:30pm-11:00pm PDT (0430-0600 UTC Apr 8) Location: Backyard near Sacramento, California 121W 16', 38N 44' Instrument: Intes 9" f/13.6 Maksutov-Cassegrain Oculars: 26, 10, 7.5mm Sirius Ploessls, Orion barlow Seeing: 7/10 Transparency: 4/10 hazy cirrus clouds Limiting mag: ~4