I forgot to mention, all these observations were through what is practically mud!!!
After I packed it in, it turns out I've been observing with an absolutely FILTHY mirror!!! Apparently towards the end of the session, some of the dew that was accumulating somehow dripped onto the primary mirror, leaving two broad streaks as the water made its way down the surface. Now, these two streaks seemingly polished the mirror of dirt, making the affected surface look shiny new compared to the rest of the mirror! I was totally shocked at how a dirty a mirror I've been using all this time without even knowing it!
Here is a pic of the mirror in my 12" dob, you can see how much cleaner the bit is where the water ran down - you can see how much better the contrast of the reflection of the black surface is in the streaks and you can also see the "banks" of dirt pushed to the side by the water as it made its way down the mirror
A clean is in order this weekend! Can't wait to get it out under the stars afterwards. Last time I cleaned the mirror on my other scope, the difference in image quality was noticable, so I'm excited
