Scientists Explore Possible Formation of Life’s Building Blocks

Life’s Building Blocks
Photo by Hubble Space Telescope / ESA

For a long time, scientists have been working and studying on how Life’s Building Blocks formed in space, and life as we know it today. In recent lab experiments, scientists believe that they have retraced the chemical steps that lead to the formation of complex hydrocarbons in space, which reveals the path to forming 2-D carbon-based nanostructures combined with heated gases.

The experiments were conducted at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), and the results of the study, which could provide an accurate explanation for pyrene, a chemical compound which is a similar compound to those sometimes found in meteorites, could contain the formation of life’s building blocks. The study was published on March 5 in the Nature Astronomy journal. The scientists at the University of Hawaii at Manoa, theoretical chemists at Florida International University participated together in the experiments on how the life building blocks formed in space.

“This is how we believe some of the first carbon-based structures evolved in the universe,” Musahid Ahmed, a scientist in Berkeley Lab’s Chemical Sciences Division who joined other team members to perform experiments at Berkeley Lab’s Advanced Light Source (ALS) said in a statement. “Starting off from simple gases, you can generate one-dimensional and two-dimensional structures, and pyrene could lead you to 2-D graphene. From there you can get to graphite, and the evolution of more complex chemistry begins.”

The molecular structure of pyrene consists of 16 carbon atoms and 10 hydrogen atoms. According to the statement, researchers discovered that those heated chemical processes which form pyrene are also similar to the combustion processes found in vehicle engines.

The new paper adds on to previous work, which included analyzing hydrocarbons along with molecular rings, earlier observed in space. One of them is Saturn’s moon Titan. It houses two prevalent hydrocarbons – benzene and naphthalene.

“When these hydrocarbons were first seen in space, people got very excited. There was the question of how they formed,” Ralf I. Kaiser, lead author of the study and chemistry professor at the University of Hawaii at Manoa said in the statement.

Pyrene, assumed to lead to the possible path of the formation of life’s building blocks, is part of a family known as polycyclic atomic hydrocarbons, or PAHs. Scientists estimate they account for roughly 20% of all carbon in the Milky Way. PAHs are organic molecules and they consist of a sequence of fused molecular rings. Scientists are working on synthesizing these molecules along with other molecules in the surroundings to explore the way the rings form in space.

As for this study, the researchers experimented with the chemical reactions coming from a combination of a complex hydrocarbon called 4-phenanthrenyl radical. It has a molecular structure consisting of a sequence of three rings, containing a total of 14 carbon atoms and nine hydrogen atoms, with acetylene.

“Those chemicals are very tedious to synthesize in the laboratory,” Felix Fischer, assistant professor of chemistry at UC Berkeley, and another contributor to the paper said in the statement.

Following experiments will look into what happens after mixing hydrocarbon gases in icy conditions, and try to simulate cosmic radiation in order to see whether that will hint at life’s building blocks.

“Is this enough of a trigger?” Ahmed said. “There has to be some self-organization and self-assembly involved” to create life forms. “The big question is whether this is something that, inherently, the laws of physics do allow.”

The study was supported by the U.S. Department of Energy’s Office Sciences, and UC Berkeley, the University of Hawaii, Florida International University, and the National Science Foundation.