Was out this evening closing up our chickens for the night and noticed an extremely bright object in our northwest sky. Had a pretty good idea what it was so went in and grabbed my C90 and set up in the side yard to have a look. With an 18mm eye piece I could easily see the "tear-drop" shape of an upper air research balloon. Noting the direction I later went in and looked up the Columbia Scientific Balloon Facility, Fort Sumner, NM site to see if they had any launches underway and indeed they did. About the time I was observing the balloon it was about 240 miles to my west northwest over far northwestern Roosevelt County at around 110,000 feet.
Doing a bit of math I figure that the vertical was around 24 arc seconds (assuming the balloon was around 150 feet) and even much less at the bottom taper of the balloon. Focus even at that distance was quite good, the edges of the balloon were a bit fuzzy. The sun was setting fast and I lost light before I could try one of the smaller eye pieces. Maybe again soon as there appears to be some more launches coming up.
Took the scope out later this evening to look at Saturn. Quite nice.