Have days on Earth always had 24 hours? Science has the answer!

Currently, the average length of a day on Earth is approximately 24 hours, meaning it takes one day for the planet to complete a full rotation around its axis. But, Scientists say the average time is 24 hours, but the exact time may vary depending on your location.For example, it takes 23 hours, 56 minutes and 4 seconds for the Earth to complete one rotation relative to the stars.

The 24-hour rotation period allowed humans and animals to develop an understanding of the length of a day; society created a set of rules to define time in just this way. It may seem strange, but the Earth did not always offer 24-hour days; that number was considerably lower a few million years ago.

A study recently published in the scientific journal Nature Geoscience suggests that around two billion years ago, a day on Earth lasted only 19 hours. At that time, it was around a billion years. This was mainly due to the proximity of the Moon, which stole some of the planet’s rotational energy. Unfortunately, there were no humans left alive to make the most of the short days.

“Earth has experienced shorter and longer days at different points in history than it does now. Most notably, it was affected by tidal interactions with the Moon. About a billion years ago, the day was only 19 hours long,” Sarah Millholland, a physicist at the Massachusetts Institute of Technology (MIT), wrote in a message on her website Live Science.

You already know that days on Earth are not always 24 hours long, but has this changed much over the years? I have prepared a text with information from astronomers and other experts in the field to better explain the length of days on Earth. Check it out!

How many hours were there in a day on Earth?

The fact is that the length of a day on Earth is 24 hours due to various coincidences. For example, if there was no balance between the gravitational pull of the Moon and the tides of the Sun, the life of the planet could be up to 60 hours a day. But in the distant past, this period was much shorter.

About 4.5 billion years ago, The Moon was much closer to the Earth and therefore the day length was less than 10 hours. During all these years, the natural satellite has been moving away from us at a rate of 3.78 centimeters per year. That’s why today a day lasts 24 hours.

“Accurate knowledge of the instantaneous rotation rate of the Earth is indispensable for accurate navigation and geographic location. Fluctuations in the length of the sidereal day are caused by the exchange of momentum between the Earth’s fluids (i.e. atmosphere, hydrosphere and cryosphere) and the solid Earth,” the study explains, which proposes a period of 19 hours.

scientists too He claims that the length of a day on Earth is constantly changing; period increases by approximately 1.7 milliseconds per century. Due to the planet’s remoteness, within a few million years future human society may experience longer days; Unless climate change destroys them all first.

After all, climate change may also be one of the reasons for the disappearance of thermal tides and, as a result, increase the length of a day on Earth. Increasing the temperature on the planet will cause the resonance frequency to increase, which will reduce the torque from the Sun and cause the days to become longer.

It can take up to 200 million years for the distance of the Moon to affect the length of the day, making a 25-hour day possible. However, there are other factors that can accelerate this process. Researchers suggest that natural events such as earthquakes and asteroid impacts may increase the Earth’s rotation rate.

Did you like the content? So, stay up to date with more curiosities about astronomy on TecMundo. Or take the opportunity to understand why the rotation of the Earth’s core is decreasing.