Is the moon moving away from the earth? NASA explains why
The moon is gradually moving further away from Earth, a phenomenon explained by NASA scientists as a result of complex gravitational interactions. Currently, the moon is drifting away at a rate of about 4 centimeters per year, a process influenced by the tidal forces between Earth and its satellite. This steady separation, while imperceptible on a human time scale, has profound consequences for the Earth-moon system and its long-term evolution, according to the space agency.
The role of tidal forces in the drift of the moon
Earth’s gravity creates bulges in the shape of the moon, while the moon’s gravity exerts similar forces on Earth, particularly on the oceans. However, Earth’s tidal bulges lag slightly behind the moon’s position, due to the time it takes for water to respond to changes in gravity, NASA says. This deceleration causes friction, slowing the Earth’s rotation and transferring energy to the moon, sending it into a higher orbit.
NASA explains that this interaction causes the moon to drift and extends Earth’s day by about 2 milliseconds per century. Over billions of years, this dynamic exchange of energy has significantly shaped the relationship between the two celestial bodies.
Implications for the distant future
If this process continues for another 50 billion years, the moon’s orbit will become so large that the Earth itself will become stuck to the moon. This would mean that only one hemisphere of Earth would ever see the moon in the sky. A similar phenomenon is already observed in the Pluto-Charon system, where the two bodies are tidally locked together.
Although such changes occur on timescales far beyond human experience, they highlight the ongoing evolution of the Earth-moon system, which began when the moon formed about 4.5 billion years ago. NASA’s research continues to unravel the complexity of these tidal interactions and provides insights into planetary systems inside and outside our solar system.
