by Akkana Peck
The weather gods smiled last Saturday on the debut of my new homebuilt 8" f/6 Newtonian, and provided warm, clear skies over Fremont Peak. I ground the mirror a year or two ago under the expert guidance of Jane Houston (thanks again, Jane!), then got stalled with various overly ambitious designs for the scope, which I intended as a highly portable travel scope. Finally taking shape as a 4-tube "truss" (not really, with only 4 tubes) dob, it saw first light (the moon!) a couple of weeks ago at an SJAA club meeting, and Saturday was its first real outing.
I didn't really intend the scope as a planetary instrument; I'm a first-time mirror grinder, and didn't expect the figure to be that great, and with a truss-tube design I can't count on perfect collimation every time. But just in case, and since planets are what I most like to look at, I outfitted it with a good, small (1.52") secondary on a Protostar 3-vane spider.
So Saturday was my first look at Jupiter, and I was quite pleased at the amount of detail visible despite the low elevation of the planet (we didn't stay terribly late) and the imperfect seeing. The timing was just right to catch the end of a Europa shadow transit, and the beginning of the transit of the moon itself, both of which were nicely visible through the 8" (though more spectacular in Dave's also newly rebuilt 12.5" Newt), and I made a rough sketch: http://www.shallowsky.com/images/sketch/jupiter9302k.jpg
I also got a chance to see Juno through the 8", when a visitor came by asking whether he could use my 8" to track it down; of course, I was happy to oblige, and he found the field, less than a degree away from M72, and drew a sketch of the star field and which one was Juno. I'm looking forward to following it on upcoming nights as it passes by M72. Other views included the crescent moon, Mercury, Venus, Saturn, Uranus, Neptune, and of course earth. A very satisfyingly shallow night!
Then last night (Monday night), with the 8" apart for painting and staining, I took a quick glance at the moon through a 6" dob before dinner, and an odd domelike hill near Gardner caught my eye. I was compelled to make a quick sketch. This morning, uploading the sketch to my web site, I discovered that I had already sketched the same area (not only is the domed hill interesting, but it's near the Apollo 17 landing site) in almost exactly the same light (last night's view was perhaps an hour later than the light for the earlier sketch). It's fun to compare what I saw on the two different occasions -- how even slightly different lighting can highlight some features and hide others, so that, for example, the "craterness" of the ghost crater Maraldi D is obvious in the earlier sketch, but in the later one its mostly-buried walls looked like unrelated wrinkle ridges. The two sketches side by side are at: http://www.shallowsky.com/gardnerhill.html
Just more proof that every look at the moon is different!
