There are basically three theories about the origin of the moon:
- It was an independent star that, passing close to the Earth, was captured in orbit.
- The Earth and the Moon were born from the same mass of matter that revolved around the Sun.
- The Moon arose from a kind of “swelling” of the Earth that was detached by centrifugal force.
A fourth explanation about the origin of the moon, which is a hybrid of the previous three, is currently accepted: the Earth collided with a massive body in space during its formation. A portion of the material was expelled and came together to create our satellite.
However, a fifth hypothesis recounts the formation of the Moon from the elements that the formative epoch’s gigantic volcanoes flung to high heights.
The Origin of the Moon: The Fission Hypothesis
The fission theory proposes that the Earth and the Moon were once one body, with a portion of the mass evacuated due to the instability induced by our planet’s tremendous rotational acceleration at the time.
The detached portion “retained” some of the initial system’s angular momentum and, as a result, remained in rotation, which, with the passage of time, became synchronized with its translation period.
The section that broke off is said to correlate with the Pacific Ocean, which is around 180 million square kilometers in size and has an average depth of 4,049 meters.
However, opponents of this theory argue that in order for such a significant piece of our planet to detach, it should have spun at such a fast rate that it could spin around in only three hours. Such a fantastic speed appears to be impossible since, if the Earth rotated too rapidly, it would not have formed due to an excess of angular momentum.
The Origin of the Moon: The Capture Hypothesis
A second idea, known as the “capture” hypothesis, holds that the Moon was an independent planetesimal star that originated at a different period and in a different location from ours.
The Moon initially had an elliptical orbit with an aphelion (farthest point from the Sun) near the planet Mercury and a perihelion (closest point to the Sun) at the distance that presently separates it from the Sun. The gravitational impacts of the big planets would have altered this orbit, altering the entire planetary system by expelling numerous things from their orbits, including our satellite.
The Moon journeyed through space for a long period before being grabbed by the Earth’s gravitational attraction. However, it is difficult to explain how the Moon’s substantial slowdown happened in order for it not to escape the Earth’s gravitational field.
The Origin of the Moon: A Binary Accretion Hypothesis
The binary accretion hypothesis proposes that the formation of the Moon and the Earth happened at the same time, from the same material, and in the same region of the solar system. The radioactive dating of lunar materials brought to our planet by numerous space missions, which dates the lunar age to between 4.5 and 4.6 billion years ago, about the age of the Earth, lends support to this notion.
The disadvantage is that if both were formed in the same area and with the same material, how could they have such a varied chemical makeup and density? The Moon is rich in titanium and unusual compounds, elements that are scarce on Earth, at least in the most superficial layer.
The Origin of the Moon: An Impact Hypothesis
The current preference appears to be the impact theory. It is assumed that a collision of the Earth with a body around one-seventh the size of our planet led to the formation of the moon. The impact caused massive pieces of matter to jump into space, where they were accreted into the Moon by a process similar to that which produced the rocky planets around the Sun.
The most skeptic-inducing element of this idea is that there would have to be just too many coincidences. At the beginning of the solar system, the likelihood of colliding with a wandering star was quite high. It is more difficult to explain why the planet did not completely disintegrate in the impact and why the shards were substantial enough to produce a satellite.
The impact theory was recreated using computers, modeling a collision with an object the size of Mars that, at a speed of less than 50,000 km/h, would allow the development of a satellite.
The Origin of the Moon: The Precipitation Hypothesis
Another interpretation, known as the “precipitation hypothesis,” has recently emerged, according to which the energy released during the creation of our planet heated some of the material, generating a hot and thick atmosphere mostly made of metal vapors and oxides. These diffused around the globe and, when they cooled, precipitated dust grains, which, when condensed, gave rise to the Earth’s sole satellite.
The Importance of the Moon to Earth
What would happen if the moon was not there? Since time immemorial, it has been one of the great mysteries of science, but thanks to technological advances, we have been able to understand the importance of the moon to earth.
The moon is the only known natural satellite of the Earth, and it is crucial to animal and plant life, as well as the balance of the many ecosystems in the environment.
The moon is one of the celestial bodies most appreciated by humans due to its crucial relevance and proximity to the Earth, and it, together with the stars, brightens the sky after the sun sets and the sky darkens. It has not been demonstrated if human life would not exist on Earth if the moon did not exist, but it is apparent that nothing would be the same.
Our satelite is gradually moving away from the Earth by about 3.8 centimeters per year, and the consequences of this phenomenon could be devastating in a few centuries, since the moon is responsible for keeping our planet’s climate stable. If the moon is too far away and has no gravitational effect on the Earth, this would have devastating climatic consequences with the progressive destruction of our planet.
Without the affectation of the moon on our lands, the time cycles would become chaotic, the Earth would go around every 8 hours instead of every 24 hours, so that a year, as we conceive it, would be composed of 1,095 days, and this would lead to a reduction in life expectancy to 25 years.
On the other hand, winds would be more hurricane-forceful than ever, with much more power and violence than those we know today. At the same time, the atmosphere would have much more oxygen and the planet’s magnetic field would be three times more intense, so that 80% of animal species would become extinct.
If you want to know more, we recommend watching the BBC documentary “Do We Really Need the Moon?” where scientist Maggie Aderin-Pocock explores and analyzes the factors that could lead to disaster if the moon were to disappear.
Influences of the Moon to Earth
As previously stated, the Moon has an impact on a variety of Earthly occurrences. The Moon has a strong impact on the tides, which are the rise and fall of the sea level every 12 hours. The influence of the moon’s gravity on the Earth causes these tides.
Because gravity increases as the distance between things decreases, when the moon is closer to the Earth, the water level rises; when the moon is farther away, the water level falls. That is, when the moon is over an ocean, the water level increases; when it is on the other side of the Earth, the water level lowers. Other stars, such as the Sun, create tides in our oceans, albeit they are less severe than those caused by the Moon.
Another way we may witness the Moon’s effect on the Earth is during eclipses, when the Moon lies between the Earth and the Sun and stops us from viewing it directly.
Moon’s impact on Individuals
There are several urban legends circulating that discuss the moon’s impact on individuals. Leaving away the most extravagant ones, such as werewolf mythology, there are still a considerable number of them that are accepted as factual despite the lack of scientific proof to back them up.
The Moon is a star that fascinates us, full of secrets and conjecture, and as we have seen throughout this essay, it has a massive impact on the world and how we live. However, we sometimes go too far in condemning it for elements that it lacks.
A common urban legend holds that the moon has an effect on our emotions, stability, or even our sleep phases, which can contribute to insomnia. The fact is that all scientific investigations have disproved this, thus we can conclude that they have no effect on our sleep patterns or moods.