Vitamin B3 is one of the most essential nutrients for life on Earth. It is used to build NAD (nicotinamide adenine dinucleotide), a vital component to metabolism, and probably a necessary element for the beginnings of life on our planet. But now new NASA-funded research suggests that much of the vitamin B3 found on Earth may actually have an extraterrestrial origin.
The study builds on previous research which found that vitamin B3 is present in carbon-rich meteorites at concentrations ranging from about 30 to 600 parts-per-billion. Scientists were even able to reproduce these results in a lab designed to simulate space-like conditions. Vitamin B3 was produced from a mixture of pyridine, a basic organic compound, and carbon dioxide ice.
The new experiments went a step further by adding water ice to the mixture. This is particularly important because water ice is abundant on comets and icy dust grains found throughout the cosmos. Sure enough, vitamin B3 could still be generated under space-like conditions from this heartier meteorite-like stew.
"We found that the types of organic compounds in our laboratory-produced ices match very well to what is found in meteorites," said Karen Smith of NASA's Goddard Space Flight Center. "This result suggests that these important organic compounds in meteorites may have originated from simple molecular ices in space. This type of chemistry may also be relevant for comets, which contain large amounts of water and carbon dioxide ices. These experiments show that vitamin B3 and other complex organic compounds could be made in space and it is plausible that meteorite and comet impacts could have added an extraterrestrial component to the supply of vitamin B3 on ancient Earth."
This is exciting news for those who expound the theory that life on Earth may have started elsewhere in the universe and traveled to our planet on comets and meteors. At the very least, the experiments demonstrate that the building blocks for life on Earth did not have to originate here. Furthermore, if the basic constituents of life are free-floating throughout space, this could increase the odds that life could form on other planets besides Earth.
Researchers hope that their results will further be validated by the Rosetta orbiter, which is currently circling comet 67P. This is the same comment that the dormant Philae lander is sitting on. If some of the same complex organic molecules used in these experiments is found in the gases released by the comet or in the comet’s nucleus, that would lend strong support to the idea that early Earth was seeded with vitamin B3 from beyond our solar system.
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