Produced by: Manoj Kumar
Earth’s days were once only 18 hours long, but the Moon’s gravitational pull is slowing our planet’s spin, stretching days over billions of years.
A study led by Gregory Dick of the University of Michigan reveals how Earth’s slowing rotation directly influenced the oxygenation of its atmosphere.
The Great Oxidation Event, driven by cyanobacteria billions of years ago, was timed with the gradual lengthening of Earth’s days, linking planetary mechanics to life.
At Lake Huron, microbial mats mimic ancient cyanobacteria, showing how oxygen production was limited by short days in early Earth’s history.
Cyanobacteria, the oxygen-producing microbes, are “late risers,” needing long daylight hours to effectively generate oxygen—a limitation tied to Earth’s shorter days.
The Moon’s influence, causing Earth’s spin to slow by 1.8 milliseconds per century, provided the extended day lengths necessary for oxygen accumulation.
Using experiments and models, scientists demonstrated how molecular diffusion and extended sunlight are critical for oxygen release in microbial ecosystems.
The research connects two major atmospheric oxygenation events—the Great Oxidation Event and the Neoproterozoic Oxygenation Event—to Earth’s slowing rotation.
Marine scientist Arjun Chennu highlights the link between molecular diffusion in microbial mats and the grand celestial mechanics of Earth and Moon.