A recent study reveals that there was a time when a day on Earth lasted only 19 hours, and this lasted for approximately 1 billion years, known as the “boring billion”.
During this phase, Earth’s tectonic activity decreased, and the process of continental drift began. On the other hand, the evolution of life almost stagnated, even in its simplest forms.
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Earth once rotated for 19 hours in a day – Photo: Earth.org
It was also during this time that the Moon was closer to Earth than it is today and remained at a constant distance. “Over time, the Moon stole rotational energy from Earth, propelling itself into a higher, more distant orbit,” explained Ross Mitchell from the Chinese Academy of Sciences and Uwe Kirscher from Curtin University, Australia, in a research paper published in the journal Nature Geoscience.
Due to the Moon’s outward movement, Earth’s rotation slowed down. Sometimes, there were days with slightly longer sunlight on Earth.
Numerous previous studies have discovered that the day on our planet has gradually lengthened over billions of years, at a rate of 0.000015 seconds per year.
In these studies, most models of Earth’s rotation predict that the length of our planet’s day has steadily increased over the past 3 to 4 billion years. For instance, a study in 2018 found that a day on Earth 1.4 billion years ago lasted 18 hours.
However, any changes in Earth’s rotation have left no geological traces.