The moon is the heart of our sky, illuminating the night and sometimes even showing its grey face during the day. Shards, crescents and full moons... people have been following the cycle of a celestial body for thousands of years. However, the usual movements of the moon were not always the same as those we observe every night in our time. The moon was much closer to Earth billions of years ago and is still moving away from Earth at a rate of 3.8 centimetres per year, NASA discovered in 1994.
When Apollo eleven landed at the Moon in 1969, the astronauts located a reflector array with inside the place of the Moon's floor called the Sea of Tranquillity. The reflector is made from fused silica half-cubes, referred to as nook cubes, established in a rectangular aluminium panel. When laser beams are directed at it from Earth, they get better off the reflector to be amassed via way of means of clinical contraptions on our planet. “Lunar ranging includes sending a laser beam thru an optical telescope,” Dr. Jean Dickey stated in 1994. “The beam enters the telescope wherein the attention piece could be, and the transmitted beam is multiplied to come to be the diameter of the primary mirror, then bounced off the floor in the direction of the reflector at the Moon.” Through this process, NASA calculated the space among Earth and the Moon at a given time. By tracking distance data, astronomers have discovered that the moon is actually drifting away from Earth as it orbits. The distance between them increases by 3.8 centimetres per year. However, this speed cannot have remained constant since the moon formed about 4.5 billion years ago, because mathematics would have put the moon and earth in the same place 1.5 billion years ago.
According to Joshua Davis and Margriet Lantink, authors of the publication, along with several other scientists, the mystery of how close the moon used to be can be solved by looking at the layers of rock.
By examining ancient erosional sediment layers in Australia, researchers were able to study the Milankovitch cycle. Milankovitch cycles are natural cycles that have changed over time and affect the perception of sunlight. These include the length of Earth's orbit and the inclination of its axis. This includes the cycle of climatic precession. "As the Earth spins, its axis wobbles in circles," explained science writer Tereza Pultarova. “This effect is called axial precession. As a result, in our time, the axis points north toward the North Star, known as the North Star. In the future he will point somewhere else.
Scientists was able to postulate that the moon was much closer 2.5 billion years ago when the rocks were forming by linking deposits in ancient rocks to this cycle. It was about 60,000 kilometres (or 37,282 miles) closer to Earth, and the day lasted just 17 hours. "It is amazing that the past dynamics of the solar system can be determined from small variations in ancient sedimentary rocks. However, one important data point does not give us a full understanding of the evolution of the Earth-Moon system," Davis and Lantic wrote. “Now we need other reliable data and new modelling approaches to follow the Moon's evolution over time. And our research team is already searching for the next group of rocks that could help us find more clues about the history of the solar system."