The building blocks of life can form even before there are stars or planets, a team of researchers have found in a study.
The new research looked at “dark chemistry”, or the ways that new kinds of materials can form without energetic radiation.
They were able to simulate the conditions that govern chemistry in space, before the stars and planets that today surround us are formed, and there are instead dense interstellar clouds that will eventually go on to form those more solid objects.
Scientists found that even within those clouds, glycine – the simplest amino acid and an important building block for life – can form. Other amino acids can probably form under those conditions too, the scientists said.
The findings are reported in a new paper, published in Nature Astronomy.
In the new study, researchers showed that it would be possible for glycine to form on the surface of icy dust grains, without energy. Previously, studies had suggest that ultraviolet radiation would be required to produce the molecule, but scientists found that could happen through “dark chemistry”.
“Dark chemistry refers to chemistry without the need of energetic radiation,” said Sergio Ioppolo, from Queen Mary University of London and lead author of the article.
"In the laboratory we were able to simulate the conditions in dark interstellar clouds where cold dust particles are covered by thin layers of ice and subsequently processed by impacting atoms causing precursor species to fragment and reactive intermediates to recombine."
Researchers say that the discovery could suggest that those molecules – which could go on to form life as we see it on Earth – could be spread more broadly through the universe than we realised. If that is true then it could be a "precursor to other complex organic molecules”, they say, going on to form them and then include them in objects such as comets, which could deliver them to Earth and other planets.
"The important conclusion from this work is that molecules that are considered building blocks of life already form at a stage that is well before the start of star and planet formation," said Harold Linnartz, Director of the Laboratory for Astrophysics at Leiden Observatory.
"Such an early formation of glycine in the evolution of star-forming regions implies that this amino acid can be formed more ubiquitously in space and is preserved in the bulk of ice before inclusion in comets and planetesimals that make up the material from which ultimately planets are made."
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