2023-05-03 02:40:42
To understand the origins of life, many scientists try to explain how amino acids were formed. Photo: Europa Press
A series of chemical experiments have shown how the solar particleswhen colliding with the gases of the primitive atmosphere from Tierracan form amino acids and carboxylic acidsthe basic components of proteins and the organic life.
The findings, which suggest that our young sun and active could have catalyzed the precursors of life more easily, and perhaps earlier than previously assumed they were published in Life magazine.
To understand the origins of lifemany scientists try to explain how the amino acidsthe raw materials from which the proteins and all cellular life. The best known proposal originated at the end of the 19th century when the scientists speculated that life might have started in a “little warm pond“: a soup of chemical products, energized by lightning, heat and other sources of energy, which could be mixed in concentrated amounts to form organic molecules.
In 1953, Stanley Miller of the University of Chicago attempted to recreate these primordial conditions in the laboratory. Miller filled a closed chamber with methane, ammonia, water and hydrogen molecular, gases which are believed to prevail in the primitive atmosphere from Tierra, and repeatedly ignited an electrical spark to simulate lightning. A week later, Miller and his graduate advisor, Harold Ureyanalyzed the content of the camera and found that 20 different amino acids had been formed.
“That was a huge revelation,” he said in a statement. Vladimir Airapetianstellar astrophysicist of the center of Goddard Space Flight from NASA and co-author of the new work. “From the components basic from atmosphere from Tierra primitive, you can synthesize these complex organic molecules.
But the last 70 years have complicated this interpretation. Scientists now believe that ammonia (NH3) and methane (CH4) were much less abundant; instead, the air of the Tierra it was full of carbon dioxide (CO2)y nitrogen molecular (N2), which require more energy to break down. These gases can still produce amino acidsbut in very small amounts.
Seeking out alternative energy sourcessome scientists pointed out the shock waves of the meteorites starters. Others cited solar ultraviolet radiation. Airapetianusing mission data Kepler from NASApoints to a new idea: energetic particles of our Sun.
Kepler observed distant stars at different stages of their cycle lifebut their data provide clues about the past of our Sol. In 2016, Airapetian published a study suggesting that during the first 100 million years of Tierrahe Sol it was 30% darker. But the “superflares” solarpowerful rashes which we only see once every 100 years or so today, they would have erupted once every 3-10 days. Are supercalls they launch particles at close to the speed of light that would regularly collide with our atmospherestarting chemical reactions.
“As soon as I posted that article, the team at the Universidad National of Yokohama of Japan contacted me,” Airapetian said.
He Dr. Kobayashiteacher of chemical there, he spent the last 30 years studying prebiotic chemistry. She was trying to understand how galactic cosmic rays (incoming particles from outside our solar system) could have affected Earth’s atmosphere primitive earth. “Most researchers ignore the good heavens galactic cosmic because they require specialized equipment, such as particle accelerators,” Kobayashi said. “I was lucky enough to have access to several of them near our testing facility.
Airapetian, Kobayashi and his collaborators created a mixture of gases that matched the atmosphere of the Tierra primitive as we understand it today. combined carbon dioxide, molecular nitrogen, agua and a variable amount of methane. (The proportion of methane in Earth’s early atmosphere is uncertain, but is believed to be low.) They fired the gas mixtures with protons (simulating solar particles) or ignited them with discharges of sparks (simulating lightning), replicating the Miller-Urey experiment for comparison.
As long as the proportion of methane were greater than 0.5%, the mixes fired by protons (solar particles) produced detectable amounts of amino acids and acids carboxylic. But spark discharges (lightning) required about 15% methane concentration before the sparks formed. amino acids.
“And even with 15% methane, the production rate of amino acids of lightning is a million times smaller than that of protons,” he added. Airapetian. Los protons They also tended to produce more carboxylic acids (a precursor to amino acids) than those ignited by spark discharges.
Other things being equal, the particles solar they appear to be a more efficient source of energy than lightning. But all else probably wasn’t the same, he suggested. Airapetian. Miller y Heart they assumed that lightning was as common in the days of the “warm little pond” as it is today. But lightning, which comes from storm clouds formed by the air warm risingwould have been rarer under a 30% darker Sun.
“During cold conditions, there is never lightning, and the Tierra primitive was under a fairly dim sun,” said Airapetian. That’s not to say it couldn’t have come from lightning, but now it seems less likely to be a rayand the particles solar seem more likely.”
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