How Moon’s movement will create 25-hour day
MANY of us feel as if there are not quite enough hours in a day – but according to scientists, this could change in the future.
Researchers have found that the effect of the Moon moving away from Earth causes our planet to spin more slowly, lengthening the day.
A new study, published in ‘Proceedings of the National Academy of Sciences’, shows that 1.4 billion years ago, a day on Earth lasted just over 18 hours. This is at least in part because the moon was closer and changed the way Earth spun around its axis.
The moon is currently moving away from Earth at a rate of 3.82cm a year, which could mean in around 200 million years’ time, each day will be 25 hours long.
Stephen Meyers, a professor of geoscience at the University of WisconsinMadison and co-author of the study, explained: “As the Moon moves away, the Earth is like a spinning figure skater who slows down as they stretch their arms out.”
This is because the Earth’s movement is at least in part determined by the bodies around it, such as other planets and the Moon, which exert force on it.
Changes in this force can effect changes in the orbit Earth traces around the Sun as well as its rotation around and wobble on its axis.
These variations, called Milankovich cycles, determine where sunlight is distributed on Earth, and so decide the planet’s climate rhythms.
These rhythms can be detected in the rock record, spanning hundreds of millions of years.
Over billions of years, time has changed significantly on Earth, because the Solar System has many moving parts, including the other planets orbiting the Sun.
Changes in the rock record can show changes in Earth’s rotation and allow scientists to map how it moved over time.
This ground-breaking new study used astrochronology, a statistical method that links astronomical theory with geological observation, to discover ancient climate change and reconstruct the history of the Solar System while looking back on Earth’s geologic past. (© Daily Telegraph, London)