Ziggyology: A Brief History of Ziggy Stardust

It was the greatest invention in the history of pop music - the rock god who came from the stars - which struck a young David Bowie like a lightning bolt from the heavens. When Ziggy the glam alien messiah fell to Earth, he transformed Bowie from a prodigy to a superstar who changed the face of music forever. But who was Ziggy Stardust?