Picture this: itโs January 24, 1973. David Bowie, the chameleonic rock star, steps onto the SS Canberra cruise ship, embarking on yet another leg of his legendary Ziggy Stardust world tour. At his side, capturing every glittering moment, is his childhood chum, Geoff MacCormack. โI remember thinking how enormous the ship was,โ MacCormack recalls, โwhich…