Ribose could arise in an extraterrestrial location

The molecular building blocks of life are organic compounds that can be assembled into proteins, RNA and DNA in living cells. To date, scientists have found most of these compounds in meteorites, comets, and interstellar dust. But the sugar ribose, which forms the backbone of RNA, has never been detected in this context. Now experimental results, published in the journal Science, suggest that even ribose can form in comets...

The new experiment mimics the conditions of the “protoplanetary disk” that formed both comets and the planets in our solar system. The researchers cooled down a mix of water, methanol and ammonia to a temperature of -195°C inside a vacuum chamber. While the mixture condensed into ice it was irradiated with ultraviolet light. This is basically what happens when icy grains – the raw material of a comet – form in a protoplanetary disk. Eventually, the ice was heated back up to room temperature, representing what happens when a comet approaches the sun. The experiment resulted in the formation of a large variety of organic compounds, including ribose and other sugar molecules.

Further details at the Christian Science Monitor and the Science link.