by Marek Cichanski
As much as I like the drive up Page Mill Road, and as much as I like the fresh air off the Pacific and the smell of the chaparral and dry grass, I've had my fill of fresh, cold, soaking wet air off of the Pacific. Right now, this is the life... clear blue sky darkening at sunset, a nearly first quarter moon hanging over the trees, the M603 pointed up, and Rukl open on my lap. Not to mention a freshly baked Trader Joe's pizza and some friends' frosty cold homebrew just a few steps away. And being able to wear shorts while observing! Yeah, observing from home is pretty ding-dang nice, sometimes. Beats freezing in the fog.
Seeing at 20:00 PDT is a lot better than it was before sunset. About 3 to 3.5 out of 5. Terminator is just at the western edges of Archimedes and Alphonsus. Nice to have it located at the edges of two prominent, well-known craters.
The "16 Nag survey" shows some of the classic features of a nearly-first-quarter moon:
Three of the big maria are entirely in the sunlight: Crisium, Fecunditatis, Tranquilitatis. Some of the eastern nearside albedo features are showing up well, namely the Palus Somnii (man, I'm obsessed with that thing), and the dark patches in southern Serenitatis. Of course, these dark features have totally different origins: The former is simply an 'exclusion zone' in a ray system, and the latter ones are dark pyroclastic deposits from late-stage mare volcanism. (At least I think they're genetically related to the maria...can't quite remember offhand...)
Imbrium is just starting to make its appearance. The big guy. The Big Kahuna. (Well, as long as we forget about things like South Pole-Aitken...) It strikes me that there's something really neat about the waxing moon: The 'Imbrium Sculpture' emerges into the light before Imbrium itself. We now know that its many linear features 'point accusingly' towards the center of Mare Imbrium. If one understands the formation of this radial sculpture, but has never seen Imbrium, then times of the lunation like this would set one all aquiver with anticipation. Well, assuming that one gets 'all aquiver' about that sort of thing... no comment...
Doesn't look like there are a whole lot of Charles Wood's L features that I need to bag tonight. Mostly lunar tourism for this observer.
Here's a fun new game to play... what's the farthest thing from Mare Imbrium that looks like it's part of the Imbrium radial sculpture? Hmm... well, there are plenty of clefts between Albategnius and Arzachel that are probably sculpture. The very small 'crater chain' of Geber A and Sacrabosco C has about the right azimuth, but I might just be kidding myself.
Whoa... I just saw the MOST BIZARRE THING EVER! I mean, the weirdest thing I've ever seen on the moon, bar none. I may have seen this before, but probably never this well. I'm talking about the crater Delaunay. According to Rukl, it's a 'heart-shaped formation 46 km in diameter, divided by a central mountain range'. Well, under tonight's illumination, that 'central mountain range' looks exactly like an extremely thin bridge over the dark floor of the crater. Easily the most powerful illusion that I've ever seen on the Moon. Much more striking than the 'bridge over the valley' near Bullialdus W, which Rukl points out. (Although Rukl's bridge is a neat feature, I must say. Nothing against it.)
Tonight yielded the best sunrise view I've had of Ptolemaeus / Alphonsus / Arzachel. There's a good bit of detail on the floor of Ptolemaeus, including several buried craters. At first glance, though, the crater floor looks perfectly flat. A good example of how much more one can see upon closer examination. The central peak of Alphonsus cast a long, skinny 'sundial' shadow across its floor, touching the inner west wall. The east wall of the crater was casting a nice 'mountain range' shadow on the floor. Great terracing on the inner W wall of Arzachel, well lit.
All in all, a nice medium-length Moon session at home. Normally I'm loath to stay away from Montebello, but tonight it was alright by me. I'll let the trees and grass and bushes enjoy some nice wet fog for a while. The coyotes and cougars can prowl around in the soft cottony mist, and then bed down in their nice snug dens. The mice can roam about the fields, safe from hawks for a change. Down here, beyond the dissipating edge of the wall of cloud, I enjoyed a good view of the good 'ol Moon. And a bed ten feet from the telescope. Life is good.
Lemon, meet juicer. Tastebuds, meet lemonade.
Posted on sf-bay-tac May 26, 2004 22:01:20 PT
Converted by report.pm 1.1 Jul 12, 2004 20:36:13 PT