Scientists have identified ribose, a basic element for the creation of life, in the icy grains that make up comets. The discovery was made during an experiment set to represent the early stage of our solar system.
Life’s origin has been puzzling scientists forever, and at the moment, they are still trying to figure out whether the molecules of life appeared on Earth or if they were brought by meteorites or comets. If the second option is true, this means the life-creating elements were also carried to other places in the universe.
Named “molecular building blocks of life”, these elements are organic compounds which can further be assembled into DNA, RNA or proteins in living cells. Until now, such compounds were found in interstellar dust, comets and meteorites. However, sugar ribose, which stands for the R in RNA, has never been detected in the same context.
RNA is quite similar to DNA in the sense that it can encode information. Some believe that in spite of being a single strand molecule, the RNA could have been used in the beginning to pass genetic information. In our times, RNA is used to deliver information from cells for the assembly of proteins. There are even some viruses that present an RNA genome.
In this light, a new experiment has been conducted that proves that this compound can be created in comets. The scientists first cooled down a mixture of water, ammonia and methanol to minus 195 degrees Celsius in a vacuum chamber. As it turned to ice, the team irradiated the mix with ultraviolet light, in order to represent the formation of icy grains in a protoplanetary disk.
However, the scientists also re-heated the chamber back to the temperature of the room for mimicking the process of a comet approaching the sun. The results published in the Science journal showed the formation of several organic compounds, including sugar ribose. However, the question of how such elements were brought to Earth remains.
It appears any type of organic material in the protoplanetary disk has to survive the pull that draws the icy grains to build asteroids and comets. While recent studies do point towards the gentleness of this process, other collisions between such celestial objects could have destroyed some organic molecules. However, scientists have also proven that by shooting bullets into ice they can create compounds like amino acids.
Image Source: Guardian Liberty Voice