Good news for those who are pressed for time: as the moon moves away from the earth, the days get longer; 1.4 billion years ago, the duration of the earth's day was only 18 hours.
When geologists say that billions of years ago the Earth was different, they usually talk about an oxygen-free atmosphere, hot climate, unrecognizable outlines of continents and oceans. Once on Earth one and a half billion years ago, you would not have recognized your home planet also because the day was then shorter than now, by as much as six hours. In a new study, published in the journal Proceedings of the National Academy of Sciences, a team of American geologists estimates how the length of the earth's day changes as the moon approaches and the tilt of the earth's axis changes.
“The moon is slowly moving away from the Earth, and our planet behaves like a skater who spins around and slowly stretches out his arms, slowing down the rotation,” explains Stephen Meyers, professor of geology at the University of Wisconsin-Madison, one of the authors of the study. In the article, Mayer's group describes the statistical method with which they were able to calculate the speed of rotation of the Earth fifteen hundred million years ago. The data obtained using this, Mayer hopes, will create accurate models of the Earth's climate change in its distant past.
The movement of the Earth in outer space is influenced by many factors: the gravitational effect of the Sun, the Moon and the planets of the Solar system; under their influence, the angle of inclination of the earth's axis, the speed of its rotation around the axis and the speed of movement along the orbit, the inclination of the orbit and its geometry change. When one or more of these parameters changes, the amount of sunlight and heat received by the Earth as a whole and its individual parts, and the dose of solar radiation reaching the Earth, also change; all this, together with atmospheric factors, determines the climate of the planet. Climate change, in turn, leaves a mark on the geological record. Mayer and his colleagues hope to use new calculations to bring geological data about the Earth's climate in the past and our understanding of the dynamics of the rotation of our planet into line.