Thank you for the helpful link.
I looked at the logon screen in 11.10 and, as predicted, there was no provision to switch back to the old interface. But there was a selection for "Ubuntu 2D", and when I tried it, I found that xephem runs perfectly with that option. I can't tell, really, what the difference between 2D and the presumed 3D version that it defaults to is. The windows in the 2D version are still animated. Maybe my "3D" version wasn't animated as much as it was supposed to be because I'm running it in a virtual machine. Who knows?
I agree with everyone at the blog you referenced -- the new look is both ugly and useless. It doesn't remind me of Windows though, I actually don't mind Windows; it reminds me of Android.
I have a feeling that I may be switching to a different version of Linux anyway. Ubuntu 11.10 was prompting me that there were upgrades available, but when I tried to upgrade, it hung.