I was in the backyard with a friend, smoking cigarettes and talking. Suddenly a piercing, ultramarine wisp caught our attention. It was about the size of a large marble and solid blue, self-illuminated. It floated down from about 15 feet above us to just a few feet above our heads in a smooth but meandering path. It didn't look like it was just riding the wind. It was too solid and blue to be an ember. It couldn't have been a laser pointer because its movement was much too steady and we were under trees that would have obscured it. It was not an insect. It was not a reflection. As suddenly as it appeared it was just gone. I asked my friend about the incident years later, and he doesn't remember it at all.