Cyanide isn’t just the last resort for the captured spies of Hollywood film. It’s also a crucial component of the early chemistry of life. And now, new research finds that cyanide might have ridden to Earth on meteorites.
Samples of a particular group of primitive meteorites — including a large one that fell near Murchison, Australia, in 1969 — all contain cyanide, bound in a stable configuration with iron and carbon monoxide. These same sorts of structures are found in enzymes called hydrogenases in modern bacteria and archaea, which could suggest that early life either borrowed from meteorites or that early Earth’s geology formed the same kind of cyanide compounds, said study co-author Michael Callahan, an analytical chemist Boise State University.
“When you study these primitive meteorites it’s like you’re hopping into a time machine and you can go back and study these ancient materials,” Callahan told Live Science. “And then you find these connections to life and ancient biology.”
Callahan and his colleagues began seeking cyanide in space rocks after publishing a 2011 paper in which they discovered nucleobases in meteorites. Nucleobases, like guanine or adenine, are among the building blocks of DNA. The chemistry of the nucleobases and their parent asteroids looked as though it depended on cyanide as a reactant, Callahan said. But he wasn’t confident that they’d be able to find any cyanide on meteorites, even if it had once existed. Cyanide is extremely reactive, Callahan said, so he expected that it would have been used up and transformed long before it landed on Earth.