Sooraj Shah ’24
It has been long believed that the requirements for life on Earth were set into motion solely by a plethora of meteorites, which contained vital minerals for the foundation of living organisms. While this is true, recent evidence suggests that lightning may have played just as large of a role. A study conducted by Benjamin Hess, a PhD student at Yale University, focused on the analysis of a sample of mineraloid called fulgurite, which is formed when lightning strikes the ground. The chemical makeup of fulgurite suggests that it played an essential part in contributing to life’s development on Earth.
The team analyzed a 2016 sample of fulgurite formed in Glen Ellyn, Illinois. Using scanning electron microscopy, a surface level image was produced, which revealed the contrasting composition of the core (made of silicon dioxide) and the outer rim (made of alpha quartz). X-ray Fluorescence Spectroscopy and diffraction were used to determine the chemical and elemental composition of the rock.
The study found a phosphorus mineral called schreibersite present in the sample of fulgurite. Although phosphorus was present during the early years of Earth, it was thought to be contained only in minerals that were insoluble in water. Schreibersite, on the other hand, can dissolve in water. When the phosphate within Schreibersite is wetted, organic molecules can be formed, creating basic units of life. Given the frequency and minimal destructive tendency of lightning strikes in comparison to meteorites, it may be plausible that lightning strikes played a bigger role than meteorites in the formation of life on Earth. Hess also noted that lightning strike frequency surpassed that of meteorites when Earth was about 3.5 billion years old, the same age as the oldest discovered microfossils. The study provides a new perspective on the creation of life on Earth, opening avenues for future research that may focus on finding fulgurite composition and formation in environments similar to early Earth and studying how lightning strikes produce phosphorus minerals when it makes contact with the ground.
Works Cited:
[1]. B.L. Hess, et. al., Lightning strikes as a major facilitator of prebiotic phosphorus reduction on early Earth. Nat Commun 12, 1535 (2021). DOI: https://doi.org/10.1038/s41467-021-21849-2
[2]. Image retrieved from:
Young Investigators Review 