I had read a Sci-Fi book by David Weber titled 'Mutineer's Moon.' It's based on the idea that the Earth's moon is actually a planetoid spaceship from the distant past that's been parked in orbit for 50,000 years. As I was reading, this came into my mind and I had to put it down. Have you ever wondered why we never see the dark side on the Moon? I used Tru Space 3 for the engine pod, and Corel PhotoPaint 8 to put it all together. And yes, I cheated - those are pictures of the Earth and Moon that I swiped as well.