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| How our days have become longer because of regular distance from the moon |
Throughout human history, the moon has been an impenetrable specter above the earth. Its mild gravity sets the tides, while its dim light enables the nocturnal mating of many species.
All ancient civilizations have set their calendars according to the moon because it is always waxing and waning, and some animals and insects find their way around with the help of sunlight reflected from the moon.
More importantly, the Moon helped create the conditions that, according to some theories, made life possible on our planet, and the Moon even helped start life on Earth. Its whimsical orbit around our planet also plays a role in some of the major weather systems that dominate our lives today.
But the moon is also slipping from our grasp
As it performs its finely balanced space dance around Earth, it orbits but never rotates, and this is why we always see only one side of the Moon. It is gradually moving away from our planet which is known as "moon distance". By firing lasers from reflectors placed on the moon's surface by Apollo mission astronauts, scientists have recently succeeded in measuring with great precision how fast the moon is receding.
They confirmed that the Moon is moving away from Earth at a rate of 1.5 inches (3.8cm) per year, and as a result, our days are getting slightly longer.
'It's all about waves,' says David Waltham, professor of geophysics at Royal Holloway University in London. The tides in the oceans slow down the rotation of the Earth and the energy generated by this causes the Moon to accelerate.
Basically, as the Earth rotates, the Moon's gravity cycles over the oceans resulting in high and low tides. These tides are actually upwellings of water that extend in an elliptical shape toward and away from the Moon's gravity. But the Earth spins on its axis much faster than the Moon's orbit above, which means that friction from the sea surface running below also pulls the water along. In other words, the water bounce or bulge moves slightly ahead of the moon in its orbit, which tries to pull it back. This gradually drains the Earth's rotational energy, slowing its rotation while the Moon gains energy, causing it to move into a higher orbit.
According to the latest analysis, this increase in our planet's rotation means that Earth's average day length has increased by about 1.09 milliseconds per century since the late 1600s. Other estimates, based on more ancient observations of solar eclipses, put the figure at 1.78 mm per century.
While none of this sounds like much, it all adds up to a profound change throughout Earth's 4.5 billion-year history.
The Moon is believed to have formed in the first 50 million years or so after the birth of the Solar System. The most popular theory among scientists is that a planet the size of Earth and Mars collided early on our Earth, forming the Moon from the resulting debris and other material.
During this early period of the solar system, the Earth was spinning so fast that the length of the day on our planet was so short that there were two sunrises and two sunsets every 24 hours.
The Moon is currently 384,400 km (238,855 miles) from Earth. But a recent study suggests that about 3.2 billion years ago, the Moon was only 270,000 kilometers (170,000 miles) from Earth, about 70 percent of its current distance.
"The rapidly rotating Earth reduced the length of the day so much that (in 24 hours) there were two sunrises and two sunsets," says Alan Feld, a physicist at Friedrich Schiller University in Germany. 'This may have reduced the temperature difference between day and night, and may have affected the biochemistry of photosynthetic organisms.'
However, other studies of this type show that the rate of the Moon's distance from Earth has also not been constant, but rather has accelerated and slowed over time. A study by geologist Venina López de Azarevic of Argentina's National University of Salta suggests that about 550-625 million years ago, the Moon was retreating by 2.8 inches (7 cm) per year.
The speed at which the moon was moving away from Earth certainly changed over time and will continue to do so in the future says Allenfield. However, for most of its history, the Moon has been moving away at a much slower rate than it is now.
Moon's Mysterious Far Side
In fact, we are living in an age when the rate of the moon's distance is unusually high. The Moon would only have to shrink at its current rate for 1.5 billion years to reach its current position, but this process has been going on since the Moon formed 4.5 billion years ago. This means that the process was very slow even in the past.
'At the moment the tides are three times higher than we expected,' says Waltham. This may also be due to the increase in the volume of the Atlantic Ocean" If the North Atlantic were slightly wider or narrower, this would not be the case," says Waltham. The models show that if you go back a few million years, the strength of ocean waves decreases because the continents were in different positions.
But this is likely to continue to change in the future. Modeling predicts that a new tidal resonance will appear 150 million years from now, and then disappear as a new 'supercontinent' forms around 250 million years from now.
So, could we eventually reach a point in the future where our moon is gone?
Given the rate at which the Moon is moving away from us, it is unlikely that the Moon will ever leave Earth completely. The sun itself may die in about five to ten billion years, and humanity may have died out long before that.
However, in the short term, humanity itself can reduce the amount of water on Earth due to self-induced climate change, which can shorten or lengthen the length of the day on Earth.
"The ice essentially suppresses the waves," says Waltham, noting that around 600-900 million years ago, when our planet is thought to have entered a particularly cold period At that time, the rate of the Moon's retrograde slowed dramatically. However, its impact is difficult to assess.
In theory, the next generation of astronauts traveling to the moon with NASA's Artemis program could be able to say they saw their home planet from a much greater distance than their predecessors in the Apollo program did 60 years ago.
As far as we humans are concerned, our own lives are so short that we don't even know the distance because our day length is increasing by only a picosecond per day. is also less for.