The heart of our galaxy truly is a weird and wonderful place. Not only does it taste like raspberries and smell like rum (wait… what?!), but it’s also packed with billions of liters of alcohol—as if space could get any more interesting? Now, it turns out that it harbors an unusual carbon-based molecule that is often found in molecules that are necessary for life. This exciting discovery could suggest that the building blocks of life may have their origins in interstellar space. I guess life and booze really do go hand in hand.
Some 27,000 light-years away from Earth, at the center of the Milky Way, lies the giant star-forming dust cloud Sagittarius B2. This cloud has billions upon billions of liters of alcohol inside it, such as methanol, vinyl-alcohol and ethanol. Beguilingly, it also contains a molecule called ethyl formate which is responsible for the flavor of raspberries and also smells like rum. Now, to add to the list of interesting things inside it, researchers have discovered the presence of a branched, carbon-based organic molecule called iso-propyl cyanide. Its structure is the closest discovered so far to the complex organic molecules of life that we are familiar with. The findings are described in the journal Science.
To make this discovery, scientists from the Max Planck Institute, Cornell University and the University of Cologne scoured the gas cloud using the Atacama Large Millimeter Array (ALMA) in Chile. ALMA consists of 66 sensitive radio telescopes that are capable of picking up the spectral signatures, or fingerprints, of different molecules in space. Researchers then have the job of matching up these frequencies to molecules that have already been identified in the lab.
It’s known that Sagittarius B2 is rife with complex interstellar organic molecules, so the team was keen to probe its chemical makeup further. Organic molecules commonly found in stellar nurseries normally consist of a single backbone of carbon atoms lined up in a straight chain. The newly spotted iso-propyl cyanide, however, is a branched carbon chain and thus represents the first detection of such a chemical in interstellar space. It’s also the largest and most complex organic molecule found so far in a star-forming cloud.
The structure of iso-propyl cyanide is a common feature in many molecules that are required for life, such as amino acids which are what proteins are made up of. Tantalizingly, this could suggest that biologically critical molecules, such as amino acids that are often found in meteorites, are forged in the early stages of star formation. Astronomers are hopeful that one day, amino acids will be discovered in our galaxy. If it turns out that they are widespread throughout the Milky Way, then it may well be that so is life. Right now, we unfortunately don’t have the instruments to be able to detect these molecules in the interstellar medium. But telescopes get more and more powerful as technology develops, so who knows what we may find in the future.