Six Moon myths and the facts behind these popular beliefs

The Moon is our only permanent natural satellite. It has a radius of about 1,080 miles and is approximately 238,855 miles away from us. For most of human history, people believed the Moon was unique, and that's the reason our natural satellite is known as 'the Moon' because no one knew that other moons even existed. In 1610, when Galileo Galilei discovered four moons orbiting Jupiter, people learned that there was more than one moon.

Since then, scientists have discovered endless facts about our natural satellite. Yet even after centuries of scientific discoveries, the Moon continues to be surrounded by myths, misconceptions, and long-held beliefs. Here are a few of the most common myths and the truth behind them.

The Moon is not moving closer to the Earth. Rather, it’s quite the opposite. As per the calculations from the laser ranging measurements, the Moon is slowly drifting 3.78 centimeters away from Earth each year. A key to this lies in Earth's tides. Tidal bulges are created when the Moon’s gravity exerts on our oceans. Our planet has a faster rotation than the speed at which the Moon orbits. This causes the bulges to stay slightly ahead of our natural satellite. Their gravitational pull transfers a small amount of Earth's rotational energy to the Moon. This results in nudging it into a slightly higher orbit and gradually farther away from our planet. 

According to Jeff Mangum of the National Radio Astronomy Observatory, “Calculations of the evolution of the Earth/Moon system tell us that with this rate of separation, in about 15 billion years the Moon will stop moving away from the Earth.”

Does the Moon have an atmosphere? Well, surprisingly, the answer is yes. However, the lunar atmosphere is pretty much different from what we experience on our Blue Planet. An extremely sparse layer of exosphere surrounds the Moon. It is so thin that the molecules rarely collide. 

The Moon's exosphere is made up mostly of helium, neon, and argon. Interestingly, scientists have also detected traces of hydrogen, which have drawn attention because hydrogen is a key ingredient in water.

The Moon does have water. But you won’t find lakes or rivers on the Moon. Instead, water can be found in the form of ice and water molecules on the lunar surface. The largest deposits of water are present in the regions that never receive sunlight. 

It exists in different forms, such as ice sheets. Or it might be buried inside the soil. Contrastingly, the chances of finding water molecules in the sunlit regions are difficult. As per NASA, “The sunlit Moon, however, has 100 times less water than the Sahara Desert, but the poles of the Moon may contain tons of ice.”

Is the Moon perfectly round? Well, when viewed from the Earth, it does seem so. But the reality is quite different. Earth's natural satellite has a slightly lopsided shape, meaning it's a bit flattened at the poles. 

University of California, Santa Cruz researchers provided their insights on the matter. They stated that billions of years ago, the young Moon was much closer to Earth. Back then, it also spun faster. As it was predominantly molten beneath a thin crust, the Earth’s gravity tugged on the Moon’s soft interior. Additionally, the rapid rotation altered its shape. Gradually, the Moon went through its cooling and solidifying process, and these distortions became permanent.

There's a common belief that the Great Wall of China is the only human-made structure that is visible from space and the Moon. The wall is very long (about 13,170 miles). But it is still not visible from the Moon with the naked eye. 

Although it's very long, it is too narrow (an average of 4 to 9 meters wide) to be seen from that distance. Despite the International Space Station being in a lower Earth orbit, the crew of the ISS also cannot spot the Great Wall of China with the naked eye from space.

As National Geographic noted in a 2019 article, an analysis of Apollo-era data revealed that the Moon is tectonically active. The moonquakes originate around cliff-like features on the lunar surface. However, unlike Earth, the Moon doesn't have erupting volcanoes or shifting tectonic plates.

Dr. Thomas R. Watters, senior scientist in the Center for Earth and Planetary Studies of the National Air and Space Museum, Smithsonian Institution, shared, "The whole idea that a 4.6-billion-year-old rocky body like the Moon has managed to stay hot enough in the interior and produce this network of faults just flies in the face of conventional wisdom." The Moon is slowly shrinking as its inner core cools. This is another reason behind the wrinkles and cracks in the lunar surface.