Enormous Moth at the Laundromat

I saw this huge, gorgeous moth crawling across the parking lot at the laundromat last night.

I don't know what kind of moth it was, but I was struck by its size and beauty. It appeared to be injured. After I got this picture, I moved it to a safer area using a piece of paper to avoid rubbing the feathers off its wings.

Does anyone know what kind of moth this is?