How do you dew?

Having lost an observing session the other week to "dew" on the corrector lens of my Schmidt-Cassegrain telescope (a common problem with these scopes). I decided to jury rig myself a cheap and effective dew shield. Indeed, it also serves as a comfy back mat if you decide to sleep under the stars next to your telescope (It was between -10 and -14 C tonight here so that was not an option). I fashioned my dew shield from a trusty RidgeRest back mat that was hiding in the basement. All it does is to insulate the corrector lens from the vast sky that pulls heat from the lens (radiative transfer), limiting the heat losses to just the local region of sky I am look at. Here is a photo of my scope in its (crappy) viewing position.....trees, houses, not enough sky.



Anyway, tonight was a comedy of errors.

No sooner than I had done a three star alignment, some insurgents created a weak electrical connection to my battery and the scope died. Once re-powered, I aligned again and then had the bright idea to collimate my scope. I took shifts (tours of duty) out in the cold collimating the scope...get warm, try again, get warm then did a three star align.

Finally, I had captured Saturn in the eyepiece and observed for a bit....Mission Accomplished! I Went inside to get warm, and when I returned Saturn had fallen below the tree tops. I steeled my hunt and noticed that I had another patch of snow-free deck to the east that might provide some viewing opportunities (my patio table had a patch of clean deck under it). So I cruised over there and proceeded to lift my patio table and replanted it into the snow off to the side. With the scope planted in this new location I could no longer see Polaris. Having lost my bearings, I pointed the mount roughly north and relied on shaky communiqués from my hand controller. I was able to find the stars it needed to do a three star align...Saturn I commanded, and Saturn appeared. I rapidly took lots of images.... unfortunately they were all overexposed. In a final bust of glory, I overexposed Saturn and took this shot revealing four of her moons!



The moons were identified based on the Solar System Simulator that NASA provides. This is it's prediction for the time that the photo was taken.

Then the dew beat my shield........and I began to question the validity of the Geneva Observing Conventions. It would be nice to get rid of some of these trees, but I don't think my neighbors would appreciate it.