Type of simple sugar, or carbohydrate, with molecular formula C5H10O5. Ribose (specifically d-ribose) is a crucial component of ribonucleic acid (RNA). RNA serves as a messenger molecule, copying genetic instructions from the DNA molecule (deoxyribonucleic acid) and delivering them to molecular factories within the cell called ribosomes that read the RNA to build specific proteins needed to carry out life processes. It is also an essential component of adenosine triphosphate (ATP), which supplies energy to living cells.

Similar to DNA, RNA also carries information for how to build and operate a living organism, and many researchers think it evolved first and was later replaced by DNA. This is because RNA molecules have capabilities that DNA lacks. RNA can make copies of itself independently from other molecules, and it can also initiate or speed up chemical reactions as a catalyst. The discovery of sugar molecules in meteorites gives some evidence to support the possibility that RNA coordinated the machinery of life before DNA. As explained by Danny Glavin, a co-author of the study at NASA Goddard, “The sugar in DNA (2-deoxyribose) was not detected in any of the meteorites analyzed in this study. This is important since there could have been a delivery bias of extraterrestrial ribose to the early Earth which is consistent with the hypothesis that RNA evolved first.”