Round blue circular object hovers and dissolves in Maine.

I was about 12 years old delivering newspapers early in the morning in late September 1965(?). It was completely dark. I was standing at the entrance road to the old Averill School on Oakland St. when I looked up in the sky toward the south and saw a round blue circular object. At first I thought it was the moon but it was 3 or 4 times larger than the moon appears in the sky and it was a solid blue color. It did not move at all and there was no sound coming from it. There were no lights on it but it seemed to produce its own light. In other words, it didn't seem as if it were illuminated by any kind of reflected light. The object was a perfect circle and completely opaque. As I saw it, it appeared two-dimensional in the sky as the moon does. After a few minutes it began to dissolve. I'm pretty sure that it maintained its shape while it dissolved. I noticed at one point while it was dissolving that I could see stars behind it which I couldn't see a few minutes before. It eventually dissolved completely. I wondered if it might be a natural organic phenomenon of some kind but it seems to me such a thing would not be perfectly round. I would like to know if anyone else has ever seen anything like this.
Date is approximate.  Please see articles about the Incident in Exeter, NH, which occurred on September 03, 1965.  PD