News > For a billion years, Earth's days were only 19 hours long

For a billion years, Earth's days were only 19 hours long

A new study suggests that Earth's day length stabilized approximately 19 hours about one to two billion years ago. The research challenges the notion that day length consistently decreased over time due to the moon's influence. This stalling of Earth's rotation coincided with significant rises in oxygen levels, indicating a possible link between the evolution of the planet's rotation and the composition of its atmosphere.