Moon Recedes 3.8 Centimeters a Year, Ending Total Solar Eclipses in About 600 Million Years
Updated
Updated · spacedaily.com · May 18
Moon Recedes 3.8 Centimeters a Year, Ending Total Solar Eclipses in About 600 Million Years
4 articles · Updated · spacedaily.com · May 18
Laser ranging off Apollo and Lunokhod reflectors shows the Moon is moving away from Earth at 3.8 centimeters a year, one of lunar science’s most precise long-term measurements.
Tidal friction drives that drift: ocean bulges transfer Angular momentum from Earth’s spin to the Moon’s orbit, lengthening Earth’s day by about 1.7 milliseconds per century.
At that pace, the Moon’s apparent size should drop below the Sun’s in roughly 600 million years, leaving only annular and partial eclipses; the plausible window is about 500 million to 800 million years.
Total eclipses are possible now because the Sun is about 400 times wider than the Moon and about 400 times farther away, making both appear nearly the same size from Earth.
The finding means humanity lives in a temporary geometric window unique in the solar system, with today’s total eclipses occurring in the late middle of a finite 4.5-billion-year Earth-Moon history.
Humanity's time coincides with total eclipses. What other fleeting cosmic wonders might we be missing?
Could future geological changes on Earth ever slow or even reverse the Moon's steady departure?
Beyond losing total eclipses, how will the Moon's retreat reshape our planet's tides, climate, and geology?
Climate Change Accelerates the Moon’s Recession: How Human Activity Is Increasing Lunar Drift by 2.6% per Century
Overview
Recent scientific discoveries reveal that human-induced climate change is not only affecting our planet but also accelerating the Moon’s recession from Earth. This happens because climate variations, such as melting ice and rising sea levels, change the way ocean tides work. These evolving tides increase tidal dissipation, which speeds up the transfer of Earth’s rotational energy to the Moon’s orbit. As a result, the Moon is drifting away from Earth faster than before. This subtle but important link shows how climate change can influence even the fundamental mechanics of the Earth-Moon system.