May 2008 AstroNotes

February, 2006. I have my 10" Discovery set up, taking in the sights of Jupiter. It’s a simple scope, great optics on a Dobsonian mount. As I'm enjoying the banded behemoth a memory popped up from years before. I'm standing outside the office and Rod McCrea (former Observatory Director) walks in with a digital camera in hand. The subject of astrophotography had started to take hold at research committee meetings, the extensive process of nightlong object tracking described in detail. Rod took a different approach; he placed his camera to the eyepiece and hit the shutter. Bam - pretty nice one of Jupiter! This was a while ago, maybe 1999 or 2000 - in those days digital cameras were certainly not what they are today. So I decide to give it a go and end up with not only a good one of the big gassy guy but also a few moons to boot - wow! It makes me wonder, Jupiter came out so well what would happen with a much larger, brighter object? There was enough of a Moon up to find out, so I pointed and clicked.

Holy smoke!! The image was, I thought, pretty remarkable – especially considering how easy it seemed to be to capture. So, with a powerful - but not too powerful - eyepiece in place I moved around a bit to see what kind of shots I could get. I found that mostly they come out fairly blurry, for every one beauty I was canning ten. Thank goodness it wasn't film! I ended the night with some pretty sweet shots on my camera to show around.

I did the same one or two other nights, then it hit me - don't we have a Lunar Challenge? A list of features that you need to identify to complete the challenge? I wonder if I got a few? So I pulled out my Moon Atlas, studied my photos and sure enough I stumbled onto 4 or 5. With a bit of momentum behind me I decided to see how far I could push that...

December 2007. Somebody shoot me. 39 Lunar features were gathered within a couple months of those first shots. Of those only one was too faint to see through the eye of the camera, though my brown peepers could make it out. That left one feature - Rimae Triesnecker. This Rimae, or "river" is an ancient lava channel. None of my first attempts were successful at all, invisible to the camera and to my eyes, how can this be? I knew the list had been completed using lesser instruments, why was this eluding me? It was comparable in size to other channels that focused in just fine, I could not understand. The only explanation was that the light was hitting it from the wrong direction. For years now I have been impressed with the way the character of the Moon changes from day to day as the day/night terminator works its way across. Maybe one edge is too smooth to accentuate the feature? There was only one answer then, every attempt had been made while the Moon was waxing, I needed to try when it was waning. For a half Moon, great, we're talking like 3AM. My first try didn't work out so great, the Moon was at 55%, the terminator was too far east, and the feature was washed out. I need the phase to be less, try again next month. Oops, next month it’s at that phase during the day, that's no good. It was the same the month after that. Oh - but in 3 months there will be a chance to catch the Moon at 53%. 3 months later I see 53% is still not enough, when is it 52%? Ah, in just 2 months, good. Two months later - clouds. Try again in 3 more months, arrgghh! It’s still too far! Next month I can catch it at 50%, we'll try that. 50% puts it in shadow. Then, after years of too much light, too much shadow or clouds I finally see it, and no sunset has ever been more beautiful! I take the shot. It’s faint but there is the slightest hint of the feature - that's it!

With pride I begin the process of assembling all the images into a Flash presentation. Along the way of course I double-check everything, I'd hate to deliver the thing and have someone catch a mislabeled feature! Unfortunately that's exactly what would have happened. I'm on the last feature, #40, a fairly unremarkable crater called Hommel. I had a note where the thing was, but I couldn't seem to find it again. The reason slowly became clear - in the shot I had which covered Hommel it was completely in shadow! NOOO! After all that, I stumble on the last feature??

As it turned out Hommel was not so hard to find. It was sensitive to being washed out so I needed a pretty precise phase but it was plainly visible on the waxing Moon. A shoulder injury kept me from looking for a couple months, but on March 12th at about 9:00 I finally put the project to bed. Hommel was mine.

I have to say, part of me - and not an inconsiderable part – is disappointed. Spock once said that "having is not so great a thing as wanting", that big brain knew what it was talking about. To call the list a "challenge list" is certainly appropriate; it turned out to be quite a challenge. But it motivated me to pull out the scope on nights I otherwise would not have. In the end I found the whole experience very rewarding and enjoyable. I really cannot say strongly enough what a worthy task the Lunar challenge is - possible with pretty much any scope - and you get to see so much along the way! Really, if you have not considered it try going to the site (the members only section) and taking a look at the challenge lists. Pull out the scope, point it at the Moon and see what you can see. You may find that one or more features are right in front of you with very little effort. Maybe the next night you'll try again and find one or two more. If you're anything like me after a few such experiences you'll be hooked! And loving it.