Joni Mitchell was right: We are stardust. Another one of the essential ingredients for life as we know it might have formed in space and then rained down on a young Earth, researchers suggest in the April 8 Science.
The simple sugar ribose — a crucial piece of the molecular machinery inside cells — can form on a blend of ices that have been blasted with ultraviolet radiation, chemist Cornelia Meinert of the University Nice Sophia Antipolis in France and colleagues report. These ices are common to comets and are thought to coat grains of interstellar dust that swirl around young stars.