by Marek Cichanski
I still had the ED80 set up from last night, and I mostly observed the Moon with a 7mm T6 Nagler, for 87x. Seeing varied a lot, from 2 to 3 (out of 5) to occasional periods of 3-4.
The first thing that struck me is that this time of the lunation is great for seeing illuminated features that extend into the area of darkness. At the tips of the illuminated crescent, there were short 'horns' that extended farther into the dark zone. It was a neat effect. In particular, there was an isolated mountain peak or crater rim near the south pole that was lit up, and which protruded above the dark limb. With a little imagination, one could say that this was a mountain that's (barely) on the far side of the moon, visible above the darkened nearside. As near as I could tell from Rukl, it might have been part of the rim of the crater Amundsen. I was able to identify some craters near the south pole - Mutus, Manzinus, Schomberger, and Schomberger A, but I had a hard time trying to pick out Scott.
The craters Scott and Amundsen are named for the two explorers who raced to the south pole in 1911-1912. Amundsen was the more careful and savvy planner, and had absorbed much useful know-how from the Inuit during his time in the Arctic, so when he went to the Antarctic, he had a nice smooth trip to the pole and back. Scott was bumming hard when he got to the pole and saw that Amundsen had won. Things got rather worse when he and his men died on the way back. There's a big statue of him in Christchurch, NZ. I'm guessing there's a big statue of Amundsen in Norway somewhere.
Mare Serenitatis was about 3/4 illuminated, and the rims of ejecta / terra material protruded westward into the dark zone, beyond the illuminated portion of the mare. It was a beautiful effect.
The big craters tonight were Aristoteles and Eudoxus in the north, and Maurolycus in the south. Theophilus and Cyrillus, last night's terminator stars, were still looking great. Aristoteles and Eudoxus had brightly illuminated rims and totally dark inner walls and floors. They looked like bottomless pits into the moon's interior. Ditto with Gemma Frisius and Goodacre, a short distance to the north of Maurolycus.
It was a good night to look for Apollo landing sites. The Apollo 17 site showed up nicely at the eastern edge of Mare Serenitatis, with the 'dark mantle' material exhibiting a good color contrast against the more normal medium-grey mare. The Apollo 11 site also showed up well, even though it doesn't lie in a nice, easy-to-spot feature the way the 17 site lies in the valley of Taurus-Littrow. It was fairly easy to spot by finding the craters Sabine and Ritter, and then hopping to the bright-rimmed crater Moltke, and then looking a bit northwest of Moltke. I like the way that Rukl gives the site the Latinized name of 'Statio Tranquilitatis'.
I finally got a good look at the Apollo 16 site, which I rarely ever seem to do. I was looking at Rukl chart 45, noting that the crater Abulfeda had that nice "illuminated rim with dark floor" effect, when I noticed that the rather inconspicuous crater Descartes was next door. This should have rung an alarm bell in my head, but it didn't. I eventually noticed the notation 'Apollo 16' on the chart, and picked my way over to the site, using the craters Descartes A and Dollond. Under this illumination, it looked really rugged. The area was also known as the Cayley Plains, but John Young said "Cayley Plains? There's nothing 'plains' about this place." It was easy to believe under tonight's illumination.
The crater Julius Ceasar also looked nice, being right on the terminator. The northern part of its floor is clearly darker than the southern part. A crater chain along its northeastern rim looked like a deep cleft. The orientation of this catena / cleft suggested that it was part of the Imbrium Sculpture.
Rima Ariadeus showed up during moments of good seeing.
After the moon went behind the building, I looked at Saturn for a little while. Took the scope up to 171x with a 2x barlow, and there were a few nice moments of seeing. During those moments, I saw a nice equatorial belt and saw the Cassini division going almost all the way around the planet.
Took a quick look at Europa around 8pm PST, and tried without much luck to see the shadow of Europa transiting the disc. Seeing wasn't quite good enough near the horizon.
I'm going to stick my head outside and see if it's still raining. If it's clear, I'll look at Jupiter again real quick.
As always, it felt really great to get out and observe a bit. If a weather miracle occurs on Friday and/or Saturday evening, I'll call in the permit for MB and post accordingly.
Posted on sf-bay-tac Thu Feb 26 23:58:42 2004 PT
Converted by report.pm 1.0 Fri Mar 12 21:16:49 2004 PT