Some 4 billion years ago, the sun shone with only about three-quarters the brightness we see today, but its surface roiled with giant eruptions. This is significant because the young sun produced a lot of energetic protons. Overall, solar protons outperformed lightning by a factor of a million. Protons also tended to produce more carboxylic acids (a precursor of amino acids) than spark discharges. While protons (solar flares) formed amino acids with methane concentrations as low as 0.5%, spark discharges (lightning) required about a 15% methane concentration before any amino acids formed at all. Kobayashi's team shot the gas-filled chamber with protons (simulating solar particles) or ignited it with spark discharges (simulating lightning), comparing which worked best. Next, they set about re-creating the Miller-Urey experiment with a mixture of gases matching early Earth’s atmosphere as we understand it today. These accelerators could be used to create energetic protons of the type produced by strong solar flares and CMEs. "I was fortunate enough to have access to several near our facilities," says Kobayashi. In 2016, Airapetian suggested a different idea: energetic particles from our sun.Ĭhemistry professor Kensei Kobayashi of the Yokohama National University heard about Airapetian's idea and offered to help test it. Others cited solar ultraviolet radiation. Seeking alternative energy sources, some scientists pointed to shockwaves from incoming meteors. These gases can still yield amino acids, but in greatly reduced quantities.
Scientists now believe ammonia (NH3) and methane (CH4) were far less abundant instead, Earth's air was filled with carbon dioxide (CO2) and molecular nitrogen (N2), which require more energy to break down. "From the basic components of early Earth's atmosphere, you could synthesize these complex organic molecules."īut then things got complicated, with further research suggesting different ingredients in the young Earth's atmosphere. "That was a big revelation," says Airapetian.
A week later, Miller and his graduate advisor Harold Urey analyzed the chamber’s contents and found that 20 different amino acids had formed. In the 1950s Stanley Miller of the University of Chicago filled a closed chamber with methane, ammonia, water, and molecular hydrogen – gases thought to be prevalent in Earth's early atmosphere – and repeatedly ignited an electrical spark to simulate lightning.
"The production rate of amino acids by lightning is a million times less than by solar protons," says Vladimir Airapetian of NASA's Goddard Space Flight Center, a coauthor of the paper, published in the April 2023 issue of Life.Ībove: An artist's concept of the early EarthĮarly research on the origins of life mostly ignored the sun, focusing instead on lightning as an energy source. New research reveals that solar flares might do an even better job. SOLAR FLARES AND THE ORIGIN OF LIFE: In 1952 the famous Miller-Urey experiment proved that lightning in the atmosphere of early Earth could produce the chemical building blocks of life. No more than minor G1-class geomagnetic storms are expected. Relatively faint and slow-moving, it was hurled into space on May 12th by an erupting filament of magnetism in the sun's southern hemisphere. Neutron counts from the University of Oulu's Sodankyla Geophysical Observatory show that cosmic rays reaching Earth are slowly declining-a result of the yin-yang relationship between the solar cycle and cosmic rays.Ī MINOR CME IS COMING: NOAA forecasters say that a CME could hit Earth's magnetic field on May 16th. Credit: SDO/HMIĬosmic Rays Solar Cycle 25 is intensifying, and this is reflected in the number of cosmic rays entering Earth's atmosphere. Solar activity should remain low for the next 24 hours. All of these sunspots have relatively stable magnetic fields that pose little threat for strong solar flares.
0 kommentar(er)
