Could Lightning Have Sparked Life on Earth? New Study Suggests It Might
A large team of chemists at Harvard University has discovered that cloud-to-ground lightning strikes might have played a role in generating some of the building blocks necessary for life on Earth.
In their paper published in Proceedings of the National Academy of Sciences, the researchers describe an experiment designed to simulate early Earth conditions and observe the results of chemical reactions induced by simulated lightning strikes.
Previous theories proposed that life might have originated from materials delivered by comets or asteroids. Cloud-to-cloud lightning strikes were also considered as a potential source of these materials. However, these theories have become less likely as research progressed. For instance, the frequency of collisions with space objects decreased significantly after Earth’s formation, and cloud-to-cloud lightning is an inefficient method for generating useful materials.
This new study presents cloud-to-ground lightning strikes as a more plausible source. To test this theory, the Harvard team created a laboratory biosphere mimicking early Earth conditions, then simulated lightning strikes across air, water, and land replicas. They analyzed the products formed, particularly those that ended up in the water.
The researchers found that carbon and nitrogen were converted into molecules potentially essential for early life. For example, carbon was transformed into carbon monoxide and formic acid, while nitrogen was converted into nitrite, nitrate, and ammonium.
Further experiments involved adding minerals similar to those found in early Earth rocks to the simulated environment, followed by additional lightning strikes. The results showed the generation of sulfide minerals, akin to those near volcanic eruptions, and an increase in ammonia production, which is crucial for life.
The researchers conclude that cloud-to-ground lightning strikes were more likely to generate life’s building blocks than comets, asteroids, or cloud-to-cloud lightning strikes.
Source: Could Lightning Have Sparked Life on Earth? New Study Suggests It Might
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