Making Ribose in Interstellar Ices

Ribose is the central molecular subunit in RNA, but the prebiotic origin of ribose remains unknown. We observed the formation of substantial quantities of ribose and a diversity of structurally related sugar molecules such as arabinose, xylose, and lyxose in the room temperature organic residues of photo-processed interstellar ice analogs initially composed of H2O, CH3OH, and NH3.

These results suggest that the generation of numerous sugar molecules, including the aldopentose ribose, may be possible from photochemical and thermal treatment of cosmic ices in the late stages of the solar nebula. Within the experimental frame used the work, precursors of both proteins (amino acids) and genetic material (sugars and their derivatives) are produced in large amounts so that if delivered from meteorites in the Earth’s environment, their co evolution may be considered one of the standing issues in prebiotic chemistry