According to my sister-in-law, the spaceship is back in its rightful place--she drove to Danville today and saw it. There are three possible explanations for its disappearance: (a) There was an invisible shield around it on Tuesday when I drove to Danville, (b) I was so busy eating potato chips I missed it, or (c) It was in the shop for service. Two of my friends--one owns a local antique shop, the other is our UPS delivery person-- agreed that they had not seen the spaceship for several months! I will make the drive again and take my camera.
Postscript: Friday, May 29. Here's a photo of the real thing--it's larger than I had thought.