The building blocks of life have been found floating near the center of the Milky Way in a discovery that increases the possibility that life may have evolved on other planets in the galaxy.
Scientists have discovered that organic molecules, known as nitriles, are abundant in interstellar clouds, supporting the theory that similar life-triggering particles hitchhiked the Earth.
The theory is known as the “RNA World” theory, which proposes that the ingredients for life reached meteorites and comets during a period of heavy bombardment about four billion years ago.
According to the scenario, life on Earth was originally based on the messenger molecule RNA (ribonucleic acid), with DNA later evolving.
“Reservoir” of the Milky Way
Nitriles can help form RNA and a team of researchers has found several types floating in a reservoir near the center of the Milky Way.
Dr. Victor Rivilla, a researcher at the Center for Astrobiology of the Higher Council for Scientific Research (CSIC) said: “Here we show that chemistry that takes place in the interstellar medium is capable of efficiently forming multiple nitriles, which they are key molecular precursors of the ‘RNA World’ scenario ”.
Life on Earth appeared about 3.8 billion years ago, about 700 million years after the formation of the planet. But how exactly it went is still a mystery.
Scientists have been looking for regions of the galaxy where complex molecules could exist and have focused on a super cold molecular cloud in the center of the Milky Way.
Using two Spanish-based telescopes, the team measured the light bouncing from the region to determine the chemical composition of its particles.
“Earth-like planetary environments”
They detected three defined nitriles and two possible compounds.
Writing in the journal Frontiers in Astronomy and Space Sciences, the authors said that the discovery not only provided further evidence in support of the “RNA world” theory, but also raised the possibility that “life evolved” in other places in the Galaxy under favorable Earth – like conditions. ” planetary environments “.
Now the team is looking for the other particles, such as basic fats, that are needed to convert nitriles into RNA.
The second author, Dr. Izaskun Jiménez-Serra, a CSIC researcher, added: “So far we have detected several simple precursors of RNA building blocks. But there are still key molecules that are missing that are difficult to detect.
“For example, we know that the origin of life on Earth probably also required other molecules such as lipids, responsible for the formation of the first cells. Therefore, we should also focus on understanding how lipids could be formed from simpler precursors available in the interstellar medium. “