Ribose formation on comets

Lab-Grown "Comet" Forms Potential Ingredient for Life
http://www.scientificamerican.com/article/lab-grown-comet-forms-potential-ingredient-for-life/?WT.mc_id=SA_DD_20160408

By sticking a bunch of ices detected by the Philae lander at comet Churyumov-Gerasimenko into a vacuum chamber and blasting it with radiation, a number of complex organic molecules were formed, including ribose, a vital building block of RNA.