(ORDO NEWS) — At the heart of the Milky Way, molecules seem to be concentrated, which combine to form RNA.
A new study of the thick molecular clouds enveloping the galactic center has revealed the presence of a wide range of nitriles, organic molecules that are often toxic on their own but are also the building blocks of molecules essential for life.
The increase in prebiotic molecules (molecules involved in the origin of life) identified in the galactic center, especially those associated with RNA, are important for our understanding of how life originates in the universe – and how it appeared here on Earth.
“Here we show that the chemistry that takes place in the interstellar medium is able to efficiently form multiple nitriles, which are key molecular precursors to the RNA World scenario,” explained astrobiologist Victor Rivilla of the Spanish National Research Council and the National Institute of Aerospace Technology in Spain.
Exactly how life d arises on Earth is a mystery that scientists are trying to get to the bottom of. This information will provide important clues to the discovery of exoplanets that are likely home to living organisms.
One version is that RNA arose first from metaphorical sludge, self-replicating and diversifying on its own; this is what is called the RNA world hypothesis.
We are unlikely to ever get direct evidence from Earth, but we can gather more and more clues to find out how plausible and plausible this scenario is.
One of the questions raised by this hypothesis concerns the source of prebiotic RNA molecules such as nitriles. Were they here on Earth from the very beginning, or could they have been brought from space on meteorites and asteroids?
We know that the inner part of the solar system, including the Earth, was subject to a period of intense asteroid bombardment very early in its history. We have also found prebiotic molecules on meteors, comets and asteroids hanging around the solar system today. Where do meteors, comets and asteroids come from?
Well, probably the clouds they were born in: cold molecular clouds from which stars are born. Once a star completes its formation from part of the cloud, the remnants of the cloud continue to form everything else in the planetary system planets, comets, asteroids, dwarf planets, and whatever else might be lurking around.
The Solar System Birth Cloud is long gone, but the center of the galaxy is filled with molecular clouds. It’s called the Central Molecular Zone, and scientists have found a group of prebiotic molecules there.
One particular cloud, named G+0.693–0.027, is particularly interesting. There is no evidence of star formation yet, but scientists believe that a star or stars will form there in the future.
“The chemical composition of G+0.693 to 0.027 is similar to that of other star-forming regions in our galaxy, as well as solar system objects such as comets,” Rivilla said.
“This means that studying it could give us important information about the chemical ingredients that were available in the nebula and that make it possible to ascend into our planetary system.”
The researchers used two telescopes to study the spectrum of light coming from the cloud. When certain elements or molecules absorb and re-emit light, this can be seen in the spectrum as a darker or lighter line.
Interpreting these absorption and emission lines can be tricky, but it can also be used to determine which molecules are present: each one has its own spectral signature.
By carefully studying and analyzing the emission characteristics from G+0.693-0.027, Rivilla and colleagues identified a number of nitriles, including cyanic acid, cyanoallene, propargyl cyanide, and cyanopropine. They also made preliminary detections of cyanoformaldehyde and glycolonitrile.
Previous observations G+0.693-0.027 indicated the presence of cyanoformaldehyde and glycolonitrile. This suggests that nitriles are one of the most abundant chemical families in the Milky Way, and that the most basic building blocks for RNA can be found in the clouds from which stars and planets are born.
But there is – Of course, as always, there is still a lot of work to be done.
“So far, we have discovered several simple precursors of ribonucleotides, the building blocks of RNA,” explained astrobiologist Isascun Jiménez-Serra, also of the Spanish National Research Council and the National Institute of Aerospace Technology.
“But there are still key missing molecules that are difficult to detect. For example, we know that 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 form from the simpler precursors available in the interstellar medium.”
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