I was doing some observing last night. Everything looked fine as I viewed the moon first under 94x and then with my 9.7mm at 242x magnification. The craters along the terminus were really clear. I then decided to view my first deep-sky object and things got strange. I was trying to view M51 and so decided to use Alkaid as a jumping off point. I centered it in my telrad and started to focus. Suddenly I was looking at something that I can only describe as an image of a dull CD. There was a circle that took up most of the objective with a smaller dark circle in the middle. Between the two circles there appeared "smudges".
At first I thought there was something wrong with my eyepiece so I switched to a second 25mm that I have. The same CD showed up. Then I thought it was perhaps some sort of reflection of the primary and secondary mirrors. That thought didn't last long because as I adjusted the telescope up and down and side to side a little bit the image moved off center. When I moved away from Alkaid to where I thought I might find M51 there was no image - but I couldn't find M51 either.
Any ides on what might have happened.