While the orbit of the Moon appears remarkably regular, the natural satellite has actually been slowly moving away from Earth. Given this, is Earth bound to lose the Moon in the future?
What Makes the Moon Drift Away?
These drifts take place due to the gravitational effects that the Moon and Earth have on each other. As per NASA, the gravitational pull of the Moon forces oceans on the Earth to bulge towards this pull. This results in lunar tides. The gravity of the Earth also has a similar effect on the Moon.
Madelyn Broome, an astrophysicist from the University of California, Santa Cruz, mentioned to Live Science that back when the Moon was formed, Earth's rate of rotation would have been remarkably faster.
According to Live Science, these forces have slowly drifted the Moon away from Earth. Broome explains that because of the gravitationally interacting systems shared by both the Moon and Earth, complete angular momentum should remain the same for the two. Angular momentum refers to the energy that a spinning object contains. Faster spinning speeds mean that angular momentum is higher, and vice versa.
Broome adds, however, that spinning rate is not the only factor that affects angular momentum. One's distance from a system's center is also important. Being farther equates to higher angular momentum, and being closer leads to lower angular momentum.
In the case of the Moon and Earth, in order to conserve angular momentum as the rotation of Earth slows down, it is important to boost the system's angular momentum. This may be an orbiting cosmic object, such as the Moon, that is moving farther away.
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How Fast Is the Moon Creeping Away?
Scientists have also been looking into the rate at which the Moon is creeping away from Earth. They were able to do so, thanks to reflective panels that were installed during NASA's Apollo missions.
In the span of more than five decades, researchers have expelled beams from the earth toward such mirrors. They also gauged the time it took for them to pick up the pulses that were reflected. With the speed of light, these specialists estimated that the Moon is getting farther from the earth by around 1.5 inches each year.
Will the Moon Leave the Earth?
Futurism notes, however, that despite this evident drift, it may only need time and space for both the Moon and Earth to solve things. According to Futurism, in roughly 50 billion years, the Moon will stop drifting away and will have a stationed and stable orbit. When this is met, the Moon and Earth will end up tidally locked to one another. Because of this, the Moon will appear at the same spot in the night sky.
However, as per Live Science, in roughly 5 billion years, the sun will start dying. It will end up swelling and becoming a huge red star, which may lead to disruptions between the earth and the moon's systems. By this time, if the Moon keeps on drifting at its current rate, it would have moved around 189,000 kilometers when the Sun consumed it.
This goes to show that the Moon and Earth are not getting separated from each other. However, there is another pressing concern: the Sun gobbling up both of them.
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