Why Does the Same Side of the Moon Always Face the Earth?
Whether we consider the movement and relationship between the Earth and its Moon coincidence or part of the grand design, the fact remains that the two bodies are closely connected. Our modern calendar is loosely based on the Moon’s rotation of slightly less than 30 days. In addition to the Moon making a complete rotation on its axis in this amount of time, it makes a revolution around the Earth once in 29.5 days.
Astronomers have devoted extensive time and effort to understanding how the movements of the Moon and Earth are connected. They theorize that the Moon actually made the revolution on its axis more quickly than it does currently. These studies indicate that the effect of gravity exerted by the Earth has caused the Moon to rotate more slowly.
Research indicates that the effect of gravity eventually caused the Moon’s movements to be “locked” or permanently connected to the Earth. The rotation of the Moon and its travel around the Earth are so much in tune that people on the Earth see only the side of the Moon that is continuously exposed to us. This phenomenon is known as “tidal locking.” The rotation is considered to be synchronous.
Astronomers also estimate that we don’t actually see a “side” of the moon. Because it is a sphere and appears to be almost perfectly round people on the surface of our planet see just over 40 percent of the Moon at any time, with some estimates ranging up to 59 percent exposed but not clearly visible.
The rotations we are discussing are not perfectly smooth and are not always the same. Because of slight variations in the elliptical orbit sometimes we are able to see slightly more of the lunar surface than at other times.
Scientists have been able to determine that the Earth’s Moon is made of rock, though there are various theories about the origin of the material. One of these theories explains the Moon’s existence as a result of or Big Impact. According to this theory, a large celestial object smashed into the Earth with such force that the object was absorbed into the planet. At about the same time a large portion of the Earth was cast into orbit around the planet. This former portion of the Earth is now the Moon, according to the Big Impact theory.
Extensive study of samples from the Moon show that the material on the lunar surface is very similar to the material that makes up the Earth. Research has shown, however, that the Moon doesn’t have organic material, as does the life-supporting soil of Earth. Not only that, no water has been discovered during exploration.
In spite of these significant differences, the Earth is affected by the existence of the Moon. The force of lunar gravitation pulls ocean water toward the Moon. The ocean on the side of the planet away from the Moon is not affected as strongly. This is the reason for obvious changes in the tides on ocean beaches.
It’s true that we generally see only one side of the moon, even during a new moon. At that time, the sun lights the portion of the moon we can’t see from Earth.