Clues To Origin Of Life On Earth

No telescope. No spaceship. Neither any help from an astrophysicist. Yet a group of material scientists has peeled layers of a cosmic onion right from their lab bench. Prof. Manish Chhowalla and co-researchers at the State University of New Jersey, Rutgers, have in fact grown those onions in their lab so that they can peel them comfortably from their terrestrial base. 

The onions are multilayered carbon balls, parts of cosmic dust floating in the regions between stars. Peeling them would give vital clues about the birth of stars. Chhowalla's work has been supported by researchers from Cambridge University, Himeji Institute of Technology in Japan and Hanyang University in South Korea. Using a transmission electron microscope, they found that the balls had light absorption property similar to dust particles found in cosmic dust. "Our study will help to understand the steps that lead to the birth of a star," write Chhowalla in a recent issue of Physical Review Letters. 

In an email interview, Chhowalla said, "The fact that carbon onions are present may indicate the composition of the vapour and temperature of the environment that prevails in the interstellar cloud." Interstellar clouds also contain basic molecules like hydrogen, ammonia and others, which go into the making of the raw materials of life. "The presence of such gases is essential for the formation of carbon onions," said Chhowalla in the interview. 

These reactions may even produce amino acids. "In the frigid conditions in interstellar clouds, some of the simplest amino acids like glycine and alanine could be produced even before the formation of stars," said Prof. Sandip Chakrabarti, an astrphysicist from the S. N. Bose National Centre for Basic Sciences, who studies extraterrestrial origin of life. "I think that the seed of life on earth came from outer space. So, this study will help those astrobiologists who are studying the chemical processes taking place in the interstellar dust and believe that raw materials of life came from space." 

Besides carbon, other nanostructures present in the cosmic dust can also be produced. "We can produce nanocrystalline structures of silicon as well as other materials in our lab," said Chhowalla. For study, silicon materials can be extracted from meteorites, which rain down on earth from space. One such meteorite is Murchison meteorite, which has yielded the crystalline structure of silicon carbide. Chhowalla and his colleagues' technique can prove handy to study such meteorites. "Carriers like meteorites are thought to have brought molecules like amino acids to earth," said Chakrabarti. "This could provide vital clues to the origin of life on earth." Besides their cosmic connection, the carbon onions also have more down-to-earth applications. 

According to Chhowalla, carbon onions can be used in energy storage and fuel cells. "We can also envision them as immensely tiny ball bearings that may be used in nanomachines built on the scale of molecules," he concluded.