A new analysis by NASA-funded researchers suggest that ancient Earth might have had an extraterrestrial supply of vitamin B3 delivered by carbon-rich meteorites.
The result supports a theory that the origin of life may have been assisted by a supply of key molecules created in space and brought to Earth by comet and meteor impacts.
"It is always difficult to put a value on the connection between meteorites and the origin of life; for example, earlier work has shown that vitamin B3 could have been produced non-biologically on ancient Earth, but it's possible that an added source of vitamin B3 could have been helpful," Karen Smith of Pennsylvania State University in University Park, Pennsylvania, said.
"Vitamin B3, also called nicotinic acid or niacin, is a precursor to NAD (nicotinamide adenine dinucleotide), which is essential to metabolism and likely very ancient in origin," she said.
This is not the first time vitamin B3 has been found in meteorites. In 2001 a team led by Sandra Pizzarello of Arizona State University, in Tempe discovered it along with related molecules called pyridine carboxylic acids in the Tagish Lake meteorite.
In the new work at Goddard's Astrobiology Analytical Laboratory, Smith and her team analyzed samples from eight different carbon-rich meteorites, called "CM-2 type carbonaceous chondrites" and found vitamin B3 at levels ranging from about 30 to 600 parts-per-billion.
They also found other pyridine carboxylic acids at similar concentrations and, for the first time, found pyridine dicarboxylic acids.
The research is published online in the journal Geochimica et Cosmochimica Acta.