Space scientists have long known that there are countless small molecules containing carbon atoms in the interstellar space. These mysterious molecules probably ejected into the vast space when stars exploded. They makeup a large amount of total carbon, hydrogen and other atoms in the universe. In fact, astronomers believe that about 20% of all the carbon in the universe exists in some form of the interstellar molecule.

Mysterious Molecules in Space

These mysterious molecules absorb distinct colors of light in the space

Many scientists believe that these molecules are responsible for a phenomenon called “diffuse interstellar bands.” It’s a spectrographic proof that something in the space (probably these molecules) absorb certain colors of light from stars and other bodies before it reaches the Earth. The “diffuse interstellar bands” show hundreds of dark absorption lines in color spectrograms. These dark bands reveal almost everything by showing nothing.

The missing colors in light coming from stars to Earth “correspond to photons of given wavelengths that were absorbed as they traveled through the space before reaching our planet.” This information should help scientists identify those interstellar molecules using spectroscopy. They will have to demonstrate in the laboratory which molecules possess the same absorptive fingerprints. However, identity of these molecules remains a mystery despite decades of effort.

Have scientists resolved the mystery of interstellar molecules?

Nobody knows the exact atomic arrangement of chemical composition of these mysterious molecules. So, it remains unproven whether these molecules are truly responsible for the “diffuse interstellar bands” phenomenon. According to a new study published in the journal The Journal of Chemical Physics, a team of scientists at the Harvard-Smithsonian Center for Astrophysics has hypothesized an exciting new possibility.

They believe that these molecules could be silicon-capped hydrocarbons such as SiC3H, SiC4H and SiC5H. Researchers led by Michael McCarthy have also presented theoretical arguments and data to back their hypothesis. They used a jet-cooled silane-acetylene discharge to create silicon-containing hydrocarbons SiC3H, SiC4H and SiC5H in laboratory. Then they analyzed the spectra of each of those hydrocarbons and conducted theoretical calculations. Researchers said that longer molecules in this silicon-containing hydrocarbon family might cause the “diffuse interstellar bands.”