When his team nailed how the droplets were electrically charged and the microlite phenomenon worked, they recreated Miller Urie’s experiment. Only without spark plugs.
Ingredients of life
After microlightning began to jump between droplets with a mixture of gases similar to those used by Miller and Urey, the team examined the chemical composition on a mass spectrometer. They confirmed that glycine, uracil, urea, cyanoethylene, and many other compounds were made. “Microlightning created all organic molecules previously observed in the Miller-Rey experiment without applying external voltages,” Zare argues.
But is it really coming closer to explaining to us the beginning of our lives? After all, Miller and Urey have already demonstrated that these molecules can be produced by electrical discharges in the atmosphere of the primitive Earth. Zare argues that is the case.
“Lightning is intermittent, so it would be difficult for these molecules to concentrate. However, when you see the waves hitting the rocks, you can assume that the spray will easily enter the gaps in these rocks,” suggests Zare. He suggests that the water in these gaps will evaporate, and the new spray evaporates over and over again. Cyclic drying allows chemical precursors to accumulate in more complex molecules. “When you go through this type of drying cycle, it causes polymerization. This is how you create DNA,” Zare argues. Because spray sources are likely common on early Earth, Zare believes the process can produce far more organic chemicals than potential alternatives such as lightning strikes, hydrothermal holes and impacts on comets.
But even if Microlightning actually produced the basic building blocks of life on Earth, it remains to be seen how they are combined with living creatures. “We didn’t create life. We demonstrated a mechanism that could give us some compounds you can find in life,” says Zare. “It’s very important to have a lot of humility in things like this.”
Advances in Science, 2025. doi: 10.1126/sciadv.adt8979
