Baby planets marinate in life-giving cyanide ‘soup’, detailed maps show
The universe may be teeming with molecules necessary for life, according to a new study. The results come from the most comprehensive maps ever made of the types and locations of chemicals in the gas and dust surrounding newborn stars.
The stars shoot up huge clouds of gas and dust, which collapse under their own weight in disc-shaped structures. The centers of these discs heat up with increased friction and pressure until they ignite into fusion-fueled stars, while the surrounding material slowly agglomerates into larger and larger chunks.
“We have known for some time that planets form in disks around young stars and that these disks contain molecules of interest in predicting the future compositions of the planets,” Karin Öberg, astrochemist at the Harvard University in Cambridge, Massachusetts.
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A few years ago, Öberg and his colleagues decided to use the Atacama Large Millimeter / submillimeter Array (ALMA), a Chilean telescope that sees in the radio part of the electromagnetic spectrum, as part of the Molecules with ALMA at scales forming planets program (MAPS). Due to their shapes and the bonds within them, different chemicals vibrate in unique ways, producing telltale signatures that ALMA can capture, according to ALMA scientists.
The team examined five protoplanetary disks, all between one million and 10 million years old, a few hundred light years from Earth. “This means that they are in an era of active planetary formation,” Berg said.
MAPS not only determines specific molecules in protoplanetary disks, but also their locations. “Planets can form many different distances from the star,” Berg said, so it’s important to know what chemicals are available in each location to build these future planets.
An incredible number of 20 papers from this vast mapping project are being published in a future special issue of the Astrophysical Journal Supplement Series; the first of these papers was made available on the arXiv preprint server on September 15th.
“The great thing is that there are multiple elements rather than one big answer,” Berg said. “I think the 20 articles provide a different piece of the puzzle.”
One of the most interesting discoveries for her was the abundance and distribution of a class of molecules known as cyanides. The simplest member of this family, hydrogen cyanide, is generally considered a poison, although many theories about the origin of life include a major role for this chemical class, she said.
“Seeing them in great abundance means the planets are forming in the kind of soup we would like to see” in order to fuel the emergence of life, Berg added.
The cyanides also tended to be concentrated towards the internal parts and mid-planes of the disks studied by MAPS – exactly where the planets are expected to appear, she said.
Such molecules could only form in an oxygen-poor environment with a lot of carbon, Berg added. This suggests that planets will be born with atmospheres rich in carbon, another point in favor of living things, since carbon is the basis of organic chemistry.
The results show that at least some of the organic building blocks of life are likely available in other star systems, but that doesn’t necessarily make it more likely for humanity to find living organisms elsewhere.
“It’s promising from an origin of life point of view,” said Berg. “But there is still a lot of work to be done.”
Living creatures would have needed a certain subset of chemicals in specific amounts to appear spontaneously, and scientists have yet to agree on what was this recipe for life.
There has been a great deal of effort in the past to understand the chemistry in the clouds that give birth to stars, as well as to analyze the molecules in asteroids and comets, which may contain information about later periods of the star. planetary formation, said Kathrin Altwegg, a planet scientist from the University of Bern in Switzerland who was not involved in the new work.
“But a step was missing,” Altwegg told Live Science – the step that determined the chemistry in protoplanetary disks, and the results of this project are now helping to fill in unexplored details.
The findings also imply that much of the complex chemical formation already takes place before the birth of stars and planets, suggesting that these molecules originate from interstellar clouds and are therefore widely distributed in space, he said. she adds.
Originally published in Live Science.