Earth’s Rotation Is Slowing Down And The Culprit Is The Moon

Image source: Max Pixel

The moon is responsible for things on Earth, like our tides and possibly even our weird dreams during a full moon, and now a new study claims that the moon is actually slowing down Earth’s days. Scientists believe that the days on Earth 1.4 billion years ago were about 18 hours and that over time the moon actually slowed down Earth’s rotation enough that our days are now 24 hours.

This study was published in the journal Proceeding of the National Academy of Science (which can be found here). Researchers have developed this theory by using an interesting approach called “astrochronology”. Wikipedia defines astrochronology as (which can be found here):

Astrochronology is the dating of sedimentary units by calibration with astronomically tuned timescales, such as Milankovic cycles, or even sunspot cycles. When used in concert with radiometric dating, it allows the resolution of timescales to a high degree of accuracy. If orbital precession cycles are identified, the dating error can be as low as 21,000 years.

Basically, astrochronology uses astrology observations about our solar system and planets and combines it with geological data and observations about the Earth. By marrying these two approaches together researchers can trace back different astrological data that gives some very interesting results. Now there is no concrete proof saying that the days on Earth were in fact 18 hours, but scientists believe that the moon’s gravitational pull is interacting with our Earth’s gravitation, causing the rotation to slow down to where it is today. One of the researchers of the study, University of Wisconsin-Madison professor Stephen Meyers said in a statement about the research, “One of our ambitions was to use astrochronology to tell time in the most distant past, to develop very ancient geological time scales. We want to be able to study rocks that are billions of years old in a way that is comparable to how we study modern geologic processes.” Can this theory ever be proven? No, not technically, but we can look at geologic records to see different time scales and even climate changes as the Earth changed over time. That means that we can study the Earth’s geologic processes to help us understand not just our own planet, but it can help us understand the moon and even our solar system.

A lunar eclipse. Image source: Wikipedia

We do know that the moon drifts away from our Earth at a rate of 1.5 inches a year, which does create a pull that has slowed the planet down. Researchers were able to use that information to trace back distances to know that 1.4 billion years ago the moon was considerably closer to the Earth. That closeness made the Earth spin faster, and one full rotation took about 18 hours. Over time the gravitation forces from the moon have acted against the gravitational forces of the Earth, which is what is causing the moon to pull away from the Earth. One of the researchers gave an example to help explain the theory. 1.4 billion years ago the moon was closer, making the Earth spin like a ballerina with its arms pulled close to their body. Over time, as the moon pulled away the Earth started slowing down, like a ballerina extending their arms to slow their rotation. As scientists are able to understand and thoroughly research this theory we can possibly predict what future events might occur.

This theory does also beg the question about our understanding of the moon, how it affects us, and how would the Earth fair if the moon were no longer here.

The Moon

An up-close view of a full moon. Image source: Wikipedia
The Moon Facts
Satellite of:Earth
Diameter2,160 miles
Orbit period:27 days
Average daytime temperature:212 Fahrenheit
Average nighttime temperatureMinus 343 Fahrenheit
Distance from the Earth:238 thousand miles
Perigee (where it is closest to Earth):225 thousand miles
Apogee (where it is farthest from the Earth):252 thousand miles
Orbit circumference:1.5 million miles
Average orbit speed:1.02 km/s

Earth would not be the planet we know and love without the moon. If you think that the moon doesn’t really affect us, check out what would happen if the moon were to suddenly disappear:

  • We could get hit by more asteroids since the moon would not be there to help protect us
  • There would be no more tides
    • Tides are caused by water’s gravitational pull to the moon
    • There would probably still be waves since waves are affected by the sun, but tides would be gone
    • Without tides, lots of sea life would be killed off without nutrients given by tides
  • Say goodbye to seasons
    • The moon actually keeps the Earth from tilting on its axis too far one way or another
    • Without the moon, the Earth could theoretically tilt towards the sun then violently tilt towards Jupiter because of the massive planets gravitation pull
    • The moon provides enough of a pull on the Earth so our planet doesn’t go haywire and we can very easily predict the seasons changing
  • Not enough hours in the day
    • As we stated earlier the moon has slowed down Earth’s rotation to a 24-hour cycle
    • Without the moon, our days could be as short as 8 to 10 hours
    • That means working all day and having absolutely no time to play video games, watch TV, or read articles on your favorite science website
  • Earth’s core might get triggered
    • This is obviously just an idea, but without the moon, our Earth might just shift around
    • Tectonic plates could shift because they would be without the moons gravitational forces for the first time in a long time

The Moons Origins

We wanted to quickly touch on the origin theories of the moon. There are many theories on the web, some saying that there was a catastrophic collision between Earth and a smaller planet and the moon was formed while other theories claim that the moon is a conglomeration of asteroids that converged into one massive moon that got caught in our pull billions of years ago. The true answer is that we have no idea where the moon came from. Any theory you see on the web, no matter how wacky it might seem, could actually be the true answer. Just like with not being able to 100% prove that the moon slows down the Earth’s rotation, we can’t really 100% say where the Earth came from. What we can do is take educated guesses and further research different ideas so we can know just a little bit more about our incredible Earth and moon.

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