Scientists have long theorized that life on Earth began when lightning interacted with gases in the early atmosphere, creating organic compounds. However, a recent study published in Science Advances presents a new perspective. It suggests that microlightning in water droplets may have played a key role in the formation of life’s building blocks, offering an alternative to the widely accepted Miller-Urey hypothesis.
How Microlightning Works in Water Droplets
Water droplets of varying sizes develop opposite electrical charges when dispersed. Larger droplets typically carry a positive charge, while smaller droplets have a negative charge. When these oppositely charged droplets come close, they produce tiny electrical discharges, termed “microlightning.” This phenomenon, observed through high-speed cameras, generates enough energy to drive chemical reactions necessary for life.
Formation of Organic Molecules Without Lightning
According to the study, led by Richard Zare from Stanford University, when room-temperature water was sprayed into a mixture of gases—such as nitrogen, methane, carbon dioxide, and ammonia—organic molecules like hydrogen cyanide, glycine, and uracil were formed. These compounds are essential for the development of life.
A Challenge to the Miller-Urey Hypothesis
The Miller-Urey experiment suggested that lightning interacting with gases in early Earth’s atmosphere could have led to the formation of organic molecules. However, this theory relies on infrequent lightning strikes across vast oceans. Zare’s study proposes that microlightning from water droplets may have occurred more frequently, providing a more consistent pathway for the creation of life’s essential molecules.
Implications for Life Beyond Earth
The findings also raise questions about the possibility of life on other planets. Similar microlightning processes could occur on planets with water and atmospheric gases, suggesting that bacteria-like organisms could exist beyond Earth.
The Role of Water Droplets in Chemical Reactions
Zare emphasized that while water is often perceived as chemically inactive, breaking it into tiny droplets transforms it into a highly reactive medium. Previous research from Zare’s team has shown that water droplets can spontaneously generate hydrogen peroxide and contribute to ammonia production.
