Days on Earth did not always last 24 hours. There was a time when one revolution of our planet took less than 10 hours. If we want precision, a day on our planet lasts 23 hours, 56 minutes, and 4 seconds. Even so, conventionally, days in calendars and clocks consider 24 hours, but it was not always this way.
In the middle of the Proterozoic era, the days on Earth only lasted 19 hours. The duration of our days is due in large part to our only natural satellite – the Moon. When the Moon was created, the Earth rotated at a speed that would seem impossible to us today. In just 10 hours, one day could be considered finished. However, the Moon came to revolutionize everything.
Bodies in space attract each other according to their weight and distance. In the case of the Earth and the Moon, their gravitational attraction caused a change in the rotation of our planet, slowing it down by around 1.7 milliseconds every century. Although the change seems insignificant, after millions of years, the sum of those milliseconds ends up becoming hours.
Unlike the Moon, the Sun accelerates the rotation of the Earth. According to a study published in the journal Science, the central star of our planetary system has a very important impact on the duration of Earth days. The Sun also produces an atmospheric tide with the same type of bulges, which speeds up the Earth’s rotation instead of slowing it down like the Moon.
During the research, the authors also explored the effects of the climate crisis on the duration of Earth days and concluded that they can be prolonged by the increase in temperature in our atmosphere. As we increase the Earth’s temperature with global warming, we are also increasing the resonant frequency, which could potentially result in longer days over the centuries.
These findings shed light on the mechanisms that have shaped the length of Earth’s days throughout history. Understanding the factors influencing the duration of our days is not only fascinating from a scientific standpoint but also has implications for various aspects of life on our planet.