2.5 billion years ago our days were way shorter

Around 2.5 billion years ago, the Earth had way shorter days and bigger Full Moons. As the ages pass, the Moon slowly drifts away from the Earth. In conjunction, the length of our day gradually gets longer. As the years pass, the Moon slowly drifts away from the Earth. In conjunction, the length of our day gradually gets longer.

2.5 billion years ago the moon used to be much closer to the earth and then our day was only 17 hours long. Now the moon is slowly moving away from the Earth, slowing down its rotation at the same time. The periodic changes in the shape of Earth's orbit around the Sun, and the orientation of its spin axis, known as Milankovitch cycles, influenced the distribution of radiation that the Earth received, as well as the climate.

A regular pattern of iron-rich layers alternating with clay-rich layers is formed and measuring the width of these bands allowed scientists to figure out the distance between the Earth and the Moon 2.4 billion years ago, as well as the duration of a day. Scientists could reconstruct the length of the Earth’s day when these formations were laid, 2.46 billion years ago. They found that at the time, the day lasted only 17 hours, much shorter than the current 24.

Currently, the distance between the earth and the moon is around 384,300 kilometres. 2.4 billion years ago, a day on Earth lasted only 17 hours. The banded pattern has been linked to periodic changes in the eccentricity or ellipticity of the Earth's orbit, at a scale of about 100,000 years.

According to research, the Earth underwent climatic changes 2.5 billion years ago because of changes to the shape of the Earth's Orbit. Also, the climate of today does not have an astronomical cause, and these shifts occurring over very short scales are because of human activities.

The current distance to the Moon gives us the very special phenomenon of total solar eclipses. This can only be possible if the apparent size of the Sun and the Moon are the same in our sky. While that’s true for now, in a few hundred million years, the Moon will be too far away, and it will be too small to give us total solar eclipses.