Sunday, August 14, 2016

Overlooking The Moon

For most of my time being an amateur astronomer, I have been interested in observing certain deep sky objects, such as clusters and double stars. Occasionally, I observe the planets, especially the two largest gas giants. Most of the time, I've been interested in studying historic methods, as well as sharing how to make the most with the least. And since 2014, I have been steadily observing the Sun, and have made, at this point, well over six hundred journaled solid observations and sketches, the majority of which have been used to produce sunspot counts.
One thing I haven't done is ever really study the Moon.
In all of my nightly observations, the Moon has been, for most of it, something of a bane.
Certainly, I've looked at it, sketched it a couple of times, and many times have imaged it. But I've never really taken the time to study it.
Which, when you really think about it, is somewhat sad.
Here it is, the nearest celestial object to the Earth, something often romanticized, something occasionally derided, sitting a short distance away.
For the past week or so, I have been playing with an erect image eyepiece that proved to be the only salvageable part from a low cost telescope. It is technically an 18mm, and like many of the simpler designs, has a remarkably narrow field of view (I'd say less than 20°). Yet the images it produces are sharp.
Initially, I tested it out on my classic Tasco 6TE-5, "Amelia", a wonderful 50mm, f/12, and found that it produced some rather nice views, if a bit claustrophobic. I tested it out on a crescent Moon, working its way over the pine trees west of our property. I had to extend the eyepiece haphazardly beyond the end of the focuser, using the thumbscrew to hold on to the elongated eyepiece by a narrow margin.
It worked enough, though, to show me that there was some promise here.
Next, I tested it on a small Meade 40mm 40AZ-P that I am experimenting with, and then I crafted an adapter to use it in my 50mm Galileoscope, where it seemed most at home.
Most of these tests were aimed at the Moon for a number of reasons. Chief among these is the fact that it was simply there. The other reason had to do with one of the main problems of this design. The complex optics train greatly reduces the light that reaches the eye. The Moon is big and bright, and both Jupiter and Saturn were still as sharp as ever. However, deeper sky objects lost their brilliance. M7, an otherwise bright cluster, was reduced by half when viewed through the Galileoscope, and nearby M6 was a ghost.
The Moon, though, was another matter.
It was sharp and well defined. When the eyepiece was used with a 2x Barlow, something I'd never considered until now, the view, while still narrow, was very good.
Last night, I decided to test the eyepiece out against my 45° erect image diagonal. I suppose that if one must have an erect image, this diagonal is certainly the best way to go, as you now have at your disposal a variety of eyepieces, though the angle take a bit of getting used to, at least for me. The telescope I chose for this was "Celeste", my Celestron 70mm f/10.
Again, an adapter had to be made to allow the erect image eyepiece to be used in the larger focuser. Since Celeste sits on a rather tall tripod, I thought that the viewing would be fairly easy. As it happened, the eyepiece and adapter extended the telescope even further, and the Moon, now near Sagittarius and a waxing gibbous, was higher in the sky. I had to slide down in my observing chair just to get my head to the eyepiece at all.
The view was certainly what I expected, however. Narrow FOV, but very sharp.
Next, I tried out the 45° diagonal with an 18mm Kellner. Naturally, the FOV expanded more than twice, but the target areas, the southern lunar highlands, were still very sharp, and to a degree more so.
Instead of demonstrating alternate viewing techniques, what these tests did more than ever was to inform me that I do not observe the Moon nearly enough.
I felt some awkwardness at the realization of this. A target I tell people to look at, on the the one hand, whilst simultaneously telling my more accomplished friends to avoid, is something I don't know well enough.
Perhaps the time has come to rectify this. Soon, not sure as to when, I am going to set out about observing a solid month of the Moon. This may be done on consecutive nights, it may be broken up over a period of weeks or months, who knows for sure.
But my lack of familiarization with our nearest neighbor in the universe is something I am going to actively seek to correct.

Sunday, August 07, 2016

Lessons From Leslie Peltier

Not too long ago, on advice from my friend Roger, I decided to start reading Leslie Peltier's autobiographical "Starlight Nights". Here, I must confess that I was only familiar with Peltier in passing. I was aware that he had written a great book on binocular astronomy, and that he was an early member of the AAVSO. Beyond that, the man was a mystery to me.
After I finished reading "Astronomy With An Opera-Glass" by Garrett P. Serviss a second (maybe third) time, I went over to this "Starlight Nights", and have been enthralled.
More than that, however, is the fact that he has touched upon some truths that I've often considered but never really have given much thought to.
The one thing that he stressed is that the best way to learn the night sky is directly, that is to say, by oneself. I suppose to a degree it is akin to that old adage from Benjamin Franklin; "Tell me and I forget, teach me and I may remember, involve me and I learn." The best way to learn the night sky is to simply go out and observe it.
The other take away I've gotten from the book so far is that the size of the instrument used to observe the night sky is really less important than the tenacity of the observer. As Serviss' book has demonstrated, something as small as an opera glass is sufficient. The great French astronomer Lucien Rudaux also felt that way. In Peltier's book, he goes into some length about how effective his first telescope, a humble 2" (50mm) terrestrial telescope was.
A terrestrial telescope, if you're not familiar with them, has a complicated optic train in order the create an erect image. From personal experience, I've found that the amount of light lost in one is quite high, certainly more so than an equivalent sized astronomical telescope.
Yet he was able to view and achieve quite a bit with this instrument. It would be easy to say it was his location, the rural reaches of Ohio, or the time period, the early 20th century, that enabled him to accomplish what he did. Perhaps so.
Though I am tempted to say balderdash.
I live in an area where, to my south, is the booming metropolis of Jacksonville, Florida. To my northeast are two paper mills that run twenty four hours a day. Nearby is a shopping area, and my own neighborhood has those bothersome sodium streetlights.
Yet I have been able to see quite a bit.
Certainly, some of the more distant objects are lost. I don't see much in the way of galaxies here, and some of the fainter deep sky objects are all but invisible. But the wonders are there.
It just requires tenacity coupled with the act of simply looking.