Unique Carbon-Based Molecule Found in Deep Space May Indicate Origins of Life

Milky Way above the antennas at the ALMA Observatory in Chile ((c) Y. Beletsky (LCO)/ESO

Astronomers from Cornell University in Ithaca, NY, Germany’s Max Planck Institute for Radio Astronomy, and the University of Cologne found an unusual carbon-based molecule called isopropyl cyanide in a gas cloud some 27,000 light years away.

Those involved with the discovery say the finding suggests the type of complex molecules needed for life may have their origins deep in interstellar space.

“We think that detecting this molecule in particular will serve as a new frontier in the degree of complexity that we can find from molecules in space,” said research team member Dr. Rob Garrod from Cornell University’s Center for Radiophysics and Space Research.

While a large majority of molecules detected in space so far have carbon in them, what makes this new interstellar molecule discovery unique, according to the researchers, is its structure and size.

The astronomers say it’s the largest molecule ever found in similar star-forming areas of space.

Also, other carbon-based molecules found in similar environments tend to have their carbon atoms arranged in a single straight chain. The bit of isopropyl cyanide found in this discovery has its carbon atoms arranged in a more complex branched structure.

Milky Way’s Galactic Center and Sagittarius B2 as seen by the ATLASGAL survey ((c) ESO/APEX & MSX/IPAC/NASA)

Scientists say that molecules that contain branched carbon structures, such as those contained within isopropyl cyanide, are quite common in materials like amino acids, which are key ingredients that are needed for life.

The researchers believe their new discovery backs up a theory that molecules crucial for the existence of life may have been delivered to planets in objects such as meteorites.  These celestial objects are thought to have been produced in the early stages of a star’s formation, before the creation of other solar system bodies such as planets.

Using the Atacama Large Millimeter/submillimeter Array, or ALMA radio-telescope, located high in the mountains of northern Chile, the U.S. and German astronomers discovered the molecule by picking up on the radio waves it transmits from deep space.

Garrod explained that he and his colleagues aimed the radio antenna dishes of ALMA toward areas of space where stars are forming and were able to detect radio signals produced by various molecules.

Each type of molecule produces radio signals at very specific frequencies.

It’s not uncommon for radio astronomers to detect dozens or even hundreds of emissions, all at different frequencies, said Garrod.

He pointed out that scientists sometimes have a bit of trouble zeroing in on the radio emission of one particular molecule. With so many different kinds of molecules in the star-forming regions of space, there’s a virtual cacophony of varied radio signals being produced.

Rob Garrod, Cornell senior research associate at the Center for Radiophysics and Space Research (Lindsay France/Cornell University)

These numerous and different signals tend to overlap each other, which often distorts and sometimes cancels out the reception of a particular molecule’s radio emission.

The astronomers found the isopropyl cyanide molecule in a huge cloud of gas and dust called Sagittarius B2, located in the constellation Sagittarius, close to the galactic center of our galaxy, the Milky Way.

Garrod said this region of space is known for being particularly rich in complex organic or carbon-bearing molecules, which is why he and his colleagues are so interested in looking for these types of molecules in space.

“We think that, eventually, these molecules that are formed in space, will eventually be incorporated into new planetary systems and may ultimately be delivered to the surfaces of planets which presumably could impact the ultimate emergence of life on those planets,” said Garrod.

The researchers described their findings in a recent edition of the journal Science.

Dr. Rob Garrod talks about his team’s discovery on this weekend’s radio edition of Science World.  You can hear the interview in the player below or you can check out the entire Science World radio program.  Program air-times and an audio feed can be found in the right hand column.