Analysis of Australian sedimentary rocks helped show that the Moon was 60,000km closer to Earth 2.46 billion years ago than it is today.
Although the current distance from Earth to the Moon is approximately 384,400 km (238,855 miles), scientists know it has been adrift for some time. One of the scientific contributions of NASA’s Apollo program in 1969 was to leave mirrors on natural rocky satellites. Subsequent lunar laser range measurement experiments showed that the moon moves 3.8 cm (1.5 inches) from its home planet each year.
This discovery presented scientists with something of a conundrum.
Backward extrapolation indicates that the Moon touched Earth about 1.5 billion years ago, but there is plenty of other evidence that the Earth is about 4.5 billion years old, indicating that the Moon has no evidence of a its collision with the Earth. .
However, the speed at which the moon glides across the sky is not constant. By analyzing the evidence from the rocks of our planet, scientists tried to understand how speeds changed and how soon the Moon and Earth were close.
Joshua Davis, a researcher at the University of Sussex, and Margaret Lantink, a postdoctoral researcher in Earth Sciences at Utrecht University, have developed a technique that seeks to reveal details of the solar system’s distant past. Their study focused on the sedimentary layers of Karigeni National Park in Western Australia, some of which reveal the oldest visible parts of the earth’s crust.
Sharing these ideas, Lantink and Davies suggested that the striped iron layers that formed on the ancient seabed led to the start of the Earth’s cycle, the axial wobble of the Earth associated with its interaction with the Moon. I’ve explained how it can help you make the decision.
Since 1972, scientists have been working on the idea that ancient rock formations are linked to climate change caused by the so-called Milankovitch cycles (the effects of Earth’s movement on climate). These cycles are associated with very cold and warm climates and can affect the size of oceans and lakes, the types of plants that grow and influence the evolution and migration of plants, you can also relate to the patterns of sedimentary rocks.
The current Milankovitch cycle lasts about 21,000 years. However, it changes depending on the distance between the Moon and the Earth.
Looking at evidence from rock strata in Australia and confirming evidence from similar strata in South Africa, the researchers believe the 11,000-year cycle observed in the rocks correlates with cycles of climate change, indicating a high probability. current session.
So they worked in reverse, showing that the precession signal reflected the distance between the Earth and the Moon 2.46 billion years ago.
Their study, published in the Proceedings of the National Academy of Sciences, concluded that the Moon was about 321,800 km (± 6,500 km) from Earth 2.46 billion years ago. This is about 62,000 km closer to Earth than it is today (currently 384,300 km) and 1.5 times the Earth’s circumference. The discovery also indicates that the duration of a day on Earth at that time was 17 hours. Researchers are now looking for other rocks that could help shed light on the past dynamics of the Earth and the Moon.
“Currently, we need more reliable data and new modeling methods to track the evolution of the moon over time, and our research team is ready to uncover further clues to the history of the solar system.” We have already begun the search for the next set of rocks that will help us, “they write. ®
