June 15, 2016
WASHINGTON (AFP) - Researchers have found an organic molecule essential to biology in interstellar space for the first time, announced experts Tuesday, a discovery that could help solve a long-time mystery.
Like humans, the organic molecules that make up the universe can lean left-handed or right-handed, a preference known as chirality. Most molecules on Earth lean left -- but scientists don't know why.
The recently discovered interstellar molecule is the most complex ever discovered outside our solar system, and the first chiral molecule detected in interstellar space.
It's "a pioneering leap forward in our understanding of how prebiotic molecules are made in the universe and the effects they may have on the origins of life," said Brett McGuire, a chemist in Charlottesville, Virginia who co-authored the research.
Scientists have found chiral molecules in meteorites on Earth and comets in our solar system, but never before in interstellar space.
The molecule, propylene oxide, was found "near the center of our galaxy in an enormous star-forming cloud of dust and gas," the National Radio Astronomy Observatory (NRAO) said in a statement.
Scientists used an extremely sensitive radio telescope to detect the molecule. They presented their findings at the American Astronomical Society meeting in San Diego, California this week, and published a paper in the journal Science.
By skewing left or right, molecules have a biological advantage, because the congruence helps them build more complicated structures.
"Propylene oxide is among the most complex and structurally intricate molecules detected so far in space," said Brandon Carroll, a chemistry graduate student at the California Institute of Technology.
"Detecting this molecule opens the door for further experiments determining how and where molecular handedness emerges."
Certain biomolecules like amino acids -- which make up proteins -- are exclusively "left-handed," while some sugars, including those that comprise DNA, all lean right.
The origin of chirality in molecules remains a mystery, but scientists are hopeful that the interstellar discovery could finally solve the puzzle by clearing up what ingredients formed the base of our solar system.
Researchers have found more than 180 molecules in space that give off a distinct vibration scientists can detect with radio telescopes.
Larger, more complex molecules have more complicated vibration patterns, making them more difficult to identify.
Scientists hope that if they can understand the chirality of the propylene oxide molecule found in space, they can gain a better understanding of chiral molecules on Earth.
The study, known as the Prebiotic Interstellar Molecular Survey, is part of nearly a decade of research by the West Virginia-based NRAO, the organization that operates the ultra-sensitive Green Bank Telescope used in the research. The facility is part of the US National Science Foundation.
