by James Turley
| Date/Time | Dec 7 2000, 2030 PDT - 2200 PDT |
|---|---|
| Lunar Data | 68% New Moon, observations near transit to the South at 67% above horizon. |
| Lunar Terminator | Selegraphic Co Longitude at 49?W |
| Location | Saratoga, CA |
| Telescopes | Orion Short Tube 400mm f/5 80mm , 6mm TV Radian (67x), No Name 45% Erecting Prism Diagonal |
| Lunar Seeing | 80% thin high clouds, lunar halo when clear. |
| Temp/Humid | 38? 72% |
| Atlas | Rukl, Atlas of the Moon, Charts 52, 51, 40. North, Observing the Moon, pp 235-243. |
Watching from my den window, the moon passes near Jupiter, the Pleiades, above Saturn, I couldn't stand it. My ST80 sits in my living room, ready to grab, ocular in place, on a lightweight Carbon One Manfrotto tripod. Photo starved, I decide to chase the glory holes in the cloudy sky. High transparent clouds quickly moving across the moon's face. Occasional bright full-spectrum rainbow halo, reminding me of a Harlequin Victorian Romance.
Pointing, my target announces itself. A beautiful sunrise east of Gassendi (Charts 51 and 52). What's that? It's Mersenius at the western edge of the Sea of Moisture (yea, right). Terminator is bisecting the flooded crater. OK, I admit it. I just cannot read a moon map from a refractor without the correct image prism. My brain can't handle it. Who cares about the loss of contrast, a 68% moon provides more than enough.
Watching the terminator, I can see the shadows of the peaks on the domed central plain of Mersenius. The terminator hits 50?W and the floor of the craterlet Mersenius N bursts into darkness. My eye gazes east to an early morning in Gassendi dominating the Sea of Moisture (Humorum). Central mountains still cast shadows. The interior of Gassendi is incredibly complicated. See North. He devotes 8 pages to this area. The floor is criss crossed by a huge number of rills, visible in my ST80. This is a good time of morning to watch (Sun at colongitude 49?W). North mentions that this crater is one of the Moon's hot spots of TLP (Transient Lunar Phenomena), mentioning *reliable* reports of red glows and bright flashes. Coincidentally, this is an area of high radon emission. Cool! OK. Leads me to put on my Violet 47 "LSD" Filter. Flash, flash.
Back to the terminator, now bisecting Billy (Rukl 40) in the Sea of Storms. I look for the Survey 1 landing site near Flamsteed. Mons Hansteen is casting a huge triangular shadow. The mountain very bright against the dark floor of the Mare Procellarum. A very thin bright ring around Hansteen, NW of Billy
Clouds roll in, thick. Break up. Billy is full of light. Rima Billy is now easily seen, running almost down to Mersenius. I gaze over to Gassendi, looking for a Flash, but a cloud rolls in.
The moon is an incredible place. I have learned to concentrate my observing sessions on a small part, maybe 2 pages of Rukl. With some back up from North. In my notes (shame on me, written directly in Rukl), I always note the time and Solar colongitude. It's interesting to revisit the same spot at Sunset, or the same colong next month. I may set my Handspring to remind me to watch Gassendi next month. And I'll always be watching for the Bright Flash in Gassendi.