A new study blames the Moon for making days longer on Earth. While studying Earth’s relationship with the moon, geoscientists have found that around 1.4 billion years ago a day on Earth was of about 18 hours and 40 minutes long. This could be partly because the Moon was closer to the Earth at that time and the planet rotated faster on its axis.
The research team claims that the Moon is moving away at a rate of 3.82cm per year, thus adding two milliseconds to our days every century. According to the researchers, the days are going to eventually lengthen significantly.
“As the moon moves away, the Earth is like a spinning figure skater who slows down as they stretch their arms out,” said Stephen Meyers, the co-author of the study. Meyers is a professor of geoscience at the University of Wisconsin-Madison.
It is believed that everything in the solar system has a gravitational field that affects the other celestial bodies nearby. Likewise, Earth’s movement in space is influenced by the force exerted by other planets and the moon. This helps determine changes in the Earth’s rotation around and wobble on its axis, and in the orbit the Earth traces around the sun. These variations are known as Milankovitch cycles.
To reconstruct the ancient history of the solar system, Prof Meyers and his team used astrochronology which is a statistical method that links astronomical theory and geological observation. They used a new computer model and compiled geological records with records of Milankovitch cycles to reconstruct the cycles further back in time.
It was found that the distance between the Earth and the moon accounted for the changes and that the moon’s gradual drift away from Earth caused the planet’s rotation to slow, which as a result has been steadily lengthening the days.
The study has been published in the Proceedings of the National Academy of Sciences.