In 1952, Stanley Miller and Harold Urey fired sparks in a gas-filled flask with the aim of reflecting the composition of the Earth’s atmosphere about 3.8 billion years ago. Their results suggest that lightning may lead to amino acids and other prebiotic molecules necessary for the evolution of life. At that time, scientists thought that the early atmosphere was mainly methane and ammonia, but by the 1990s, experts insisted on an atmosphere filled with carbon dioxide and molecular nitrogen.
Now, new research suggests that the composition of the Earth’s primordial atmosphere probably made it difficult to generate. LightningThis may have increased the time it takes to generate and accumulate life-critical prebiotic molecules.
Lightning behavior in different atmospheric compositions
Electrons behave differently in an atmosphere composed of methane and ammonia and in an atmosphere composed mostly of ammonia. carbon dioxide When Molecular nitrogen.. It is not surprising that lightning discharges also behave differently, which can affect the potential for prebiotic molecules to form on the early Earth. However, few have modeled how lightning discharges change in different atmospheric environments.
To find out how often electrons and gas molecules collide in two versions of the early Earth’s atmosphere, Köhnetal. Modeling the probability of discharge sparks — Lightning strike.. They found it difficult for lightning to disperse sparks in a carbon dioxide and nitrogen atmosphere.
“Basically, in a nitrogen- and carbon-rich atmosphere, a stronger electric field is needed to initiate a discharge,” said Christoph Korn, a scientist at the National Institute of Space Research at the Technical University of Denmark, who led the study. I am.
Model revealed carbon dioxide and nitrogen atmosphere A nearly 28% stronger electric field was required for the streamer to discharge because it is unlikely that gas molecules and electrons would collide and accumulate charges that could cause a lightning strike. Spatial and time scale-ups suggest that lightning strikes may have been less early in Earth’s history, making them less likely to produce prebiotic molecules.
“If lightning discharge is involved in the production of prebiotic molecules, it is important to have a very good theoretical understanding of what happened,” says Köhn. “The big question is still where do all these prebiotic molecules come from?”
In this study, the early stages of a lightning strike, that is, spark Start a strike. For Köhn and his colleagues, the next step is to model the entire lightning strike and combine it with a model of atmospheric chemistry.Together these studies can give a more complete investigation of how lightning may be linked. Prebiotic molecule..
Rebecca Dzombak, lightning was difficult to form in the early Earth’s atmosphere, Eos (2022). DOI: 10.1029 / 2022EO220187 C. Köhnetal, Streamer Discharge in the Primitive Earth’s Atmosphere, Geophysics Research Letter (2022). DOI: 10.1029 / 2021GL097504
American Geophysical Union
This story has been republished in courtesy of Eos, sponsored by the American Geophysical Union.Read the original storyHere..
Quote: The early Earth’s atmosphere was obtained from https://phys.org/news/2022-04-early-earth-atmosphere-conducive-lightning.html on April 11, 2022 (April 2022). 11th) did not encourage
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The early Earth’s atmosphere did not contribute to lightning
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