Scientists Detect First Mirror Image Molecule in Deep Space

Astrochemists from the California Institute of Technology (Caltech) have detected the first evidence of chiral molecule in the interstellar space 28,000 light years away from Earth.

Chiral molecules are two enantiomeric forms that are almost identical but are actually different molecules. These molecules have may behave same way physically in terms of melting, freezing, and absorbing light. However, each of the "twin" molecules may react chemically with other substances in different ways. Chiral molecules are known to be "handed" molecules and can be typically found in meteors and comets, but never been detected before in interstellar space.

The chiral molecule found in the stellar space is the propylene oxide (CH3CHCH2O), which is being used on Earth to make polyethylene plastics. It is detected near the center of our Milky Way galaxy in a star-forming cloud of dust and gas known as Sagittarius B2 (Sgr B2).

"Propylene oxide is among the most complex and structurally intricate molecules detected so far in space," said Brandon Carroll, a chemistry graduate student at Caltech, in a statement. "Detecting this molecule opens the door for further experiments determining how and where molecular handedness emerges and why one form may be slightly more abundant than the other."

However, researchers can't determine if the propylene oxide detected in the Sgr B2 were left-handed, right-handed or both.

For their study, which was published in the journal Science, researchers used the National Science Foundation's Green Bank Telescope in West Virginia and the Parkes radio telescope in Australia.

Data from the radio telescope suggests the existence of propylene oxide in a shell of gas outside the core of Sgr B2. These findings support previous notions proposing that complicated molecules can be formed on ice grains in diffuse clouds of interstellar gas and dust.

The discovery of chiral molecules in interstellar space can help researchers understand how chiral molecules from space may have crashed in the Earth leading to the formation of life.

"This [discovery] is going to provide us with a laboratory to try to test theories about the role that chiral molecules played in the origins of life here on Earth and how that chirality might play a role in the origins of life elsewhere in the galaxy," explained Brett McGuire, a researcher at the National Radio Astronomy Observatory in Virginia, in a press conference.