Coyote Sat 16-Aug-2003

by Matthew Marcus

I went to Coyote specifically because I knew that the moon would be hidden behind the hills for an hour or so. That's why I didn't go to Lake Sonoma, though I guess Coe would have given the same result.

When I got there, there was no other observer. Right around sunset, someone pulled up, saw my scopes, and we started chatting about astronomy. Antonio has a small scope of his own, but he didn't know that Coyote was open for astronomy so he hadn't brought it. He was there to play in the water. Since he didn't have his own, I showed him eye-candy views from my scope. Maybe we'll see Antonio again.

The seeing was pretty good but not great. Epsilon Lyrae was split, but not as cleanly as I've seen, and the Airy rings weren't clearly visible around each star. It was relatively warm, with no wind, so Antonio could observe in T-shirt and shorts for quite a while.

Sometime around 9 or so, Jake pulled in. I knew he was One Of Us because he was running only with parking lights. He set up his Nexstar 11 and when Mars came up, started snapping pix with a digicam. He'll post the results. As far as I could tell from the tiny viewfinder, it worked pretty well.

Jake and I traded views for a while until Mars got good enough to do something with, then we each did our imaging in our own ways - him with his camera and me with pencil and paper. By 11:30 or so, it had risen enough to make filtered views spectacular. I used a red filter and saw quite a few features, including fugitive wisps which strongly reminded me of the 'canals', stretching north from the main dark features. I could see how the old-timers would put these on their maps. I also saw plenty of real features. Without a Mars map program, I couldn't identify them, but I did sketch. The polar cap was much smaller than even a week or two ago. Maybe next week it will be gone and I won't know which hemisphere is which :-) In receeding, it left behind several diffuse markings which had been covered up by ices.

As usual, I found that a color filter, almost any color filter, helps greatly by reducing the excessive light level and also by reducing the atmospheric dispersion.

I observed at 250x. We tried my 8mm EP in Jake's scope (fl=2800mm), but the resulting 350x mag was too much. Jake used a 12mm EP, for 233x. We found similar results with a DSO, the Peanut Nebula (7027 in Cyg).