A NASA scientist has discovered sugar and several related organic compounds in two meteorites — providing the first evidence that another fundamental building block of life on Earth might have come from outer space.
Dr. George Cooper and coworkers from the NASA Ames Research Center found the sugary compounds in two carbon-rich (or carbonaceous) meteorites. Previously, researchers had found inside meteorites other organic, carbon-based compounds that play major roles in life on Earth, such as amino acids and carboxylic acids, but no sugars.
These discoveries add an important new piece to the puzzle of the origins of life on Earth, and supports the notion that seeds of life might be spread far and wide around the cosmos.1
“Finding these compounds greatly adds to our understanding of what organic materials could have been present on Earth before life began,” Cooper said. “Sugar chemistry appears to be involved in life as far back as our records go.” Recent research using ratios of carbon isotopes have pushed the origin of life on Earth to as far back as 3.8 billion years, he said. (An isotope is one of two or more atoms whose nuclei have the same number of protons but different numbers of neutrons.)
“This discovery shows that it’s highly likely organic synthesis critical to life has gone on throughout the universe,” said Kenneth A. Souza, acting director of astrobiology and space research at Ames. “Then, on Earth, since the other critical elements were in place, life could blossom.”
Abstract:1 at least one sugar and a variety of sugar derivatives (polyols) have been found in the Murray and Murchison carbonaceous meteorites. The idea that extraterrestrial material may have played a role the origin of life on Earth stems in large part from the previous discovery of amino acids in these meteorites, and the presence of polyols adds weight to the argument. The sugar has been identified as dihydroxyacetone, which can readily yield higher sugars including ribose (as in an ‘RNA world’) in aqueous solution with minerals, and the polyols include glycerol, a constituent of all cell membranes.
WebElements December 10th, 2009