Complex Cyanides Observed In Deep Space

Astrochemists using the powerful Atacama Large Millimeter/submillimeter Array (ALMA) observatory in the Chilean Andes have detected multiple cyanides in the spinning mass of a protoplanetary disk surrounding a distant star (Nature 2015, DOI: 10.1038/nature14276). This first-ever discovery suggests that complex organic chemistry is ubiquitous in newly forming solar systems. Small molecules with C–N bonds interest astrochemists because they are often precursors to amino acids and other biomolecules. A team led by Karin I. Öberg of the Harvard-Smithsonian Center for Astrophysics set ALMA’s sights on the disk surrounding the star MWC 480, which has about twice the mass of our sun and is 455 light-years away. The group was able to identify the radio-frequency spectra of hydrogen cyanide (HC≡N), which has been found in such disks before, and the more complex acetonitrile (CH₃C≡N) and cyanoacetylene (HC≡C–C≡N) in the disk’s icy outer regions. This area corresponds to where volatile-laden comets formed in our solar system. The discovery implies that “the rich organic chemistry of our solar nebula was not unique,” the researchers write.