Earth may have received vitamin B3 supplied by carbon-rich meteorites, according to NASA-funded researchers, supporting the theory that earthly life may have originated with extraterrestrial assistance.
Vitamin B3, also known as nicotinic acid or niacin, is a precursor to compounds essential to metabolism, and has long been believed to have possible origins beyond ancient Earth.
Researchers previously found vitamin B3 in 2001 in the Tagish Lake meteorite.
Another team of researchers, at NASA's Goddard Space Flight Center in Greenbelt, Md., recently analyzed samples from eight different carbon-rich meteorites and found vitamin B3 at levels ranging from about 30 to 600 parts-per-billion.
The researchers said they found less vitamin B3 on meteorites that came from asteroids that were more altered by liquid water – a pattern that suggests extraterrestrial origins.
They also simulated interstellar space conditions in the lab to show synthesis of vitamin B3 and other pyridine carboxylic acids could be possible on ice grains.
Scientists believe the solar system formed when a dense cloud of gas, dust, and ice grains collapsed under its own gravity, and some of that matter clumped into comets and asteroids and then collided together to form the building blocks for planets and moons.
Radiation from nearby stars or violent events in deep space may have powered chemical reactions in the nebula that formed the solar system, scientists say, and some of those reactions could have produced biologically essential molecules such as vitamin B3.
The NASA-funded research team doubts the vitamin B3 they found came from terrestrial life because it was found along with other molecules with the same chemical formula but different atomic structures that aren’t used by life.
Life makes only the molecules it needs, scientists said, so if life was the source of the vitamin B3 molecules, then only the vitamin would have been found – and not the other, related molecules.
The team plans to conduct more interstellar simulations to better understand how vitamin B3 formed on ice grains in space.
[Image via Agence France-Presse]