The Origin of the Moon - Essay Example

The Moon The moon has been the of wonder, story, rhyme and song since the beginnings of mankind. People’s fascination with the moon has extended to fairy tale and myth, religious ceremony, hunting and farming rituals, boating routines and romance. The moon has been a fundamental element of human culture which is understandable given that if the moon did not exist, neither would humans. In the context of the history of man, only relatively recently have humans reached the moon and discovered how it was likely formed and what it consists of. The moon allows and sustains life on Earth, affects its tides daily and though not a mystery to the same degree as it had been throughout all of history, it continues to inspire the imagination and much remains to be learned of Earth’s closest celestial neighbor. Today, people more or less look upon the moon as ‘eye candy’ and pay little attention to its cycles. This was not the case for our ancestors who carefully monitored its movements. Several calendars of ancient civilizations were based on the cycles of the moon and some are currently such as the Islamic calendar. The date of the Chinese New Year is set by the cycle of the moon. The Sun was used by man until relatively recently to measure short intervals of time but the moon was judged more reliable for longer time measurements. What is commonly known as a month is based on the 29-day cycle of the moon. The term ‘month’ is derived from the term ‘moonth.’ “Without the moon’s cycle we might have ended up with a very different way of keeping track of time, and we most probably would have called it something other than a month” (Miles & Peters, 2001). The Christian celebration of Easter is calculated by determining the first Sunday following the first occurrence of a ‘full’ moon subsequent to the beginning of the Spring Equinox. The reason for this is that Christians had traditionally used the light of the ‘full’ moon to aid in their pilgrimage to their holy lands for Easter. Though the moon is the closest object to Earth and has been explored by man, questions remain regarding its exact origins and whether or not life ever existed on or within it or if it could sustain life. It was discovered more than a century ago that the moon’s density is less then Earth’s. Galileo noticed craters on the moon’s surface through the use of the telescope in the 1600’s. Currently, more is known about the moon than any other celestial body, knowledge that was inconceivable until recent times (Hamilton, 2005). Prior to the common use of telescopes, when the moon was viewed unaided, all that could be discerned were two distinct kinds of topography, dark and bright areas configured in a way that produced the illusion of the ‘Man in the Moon.’ This myth was likely known as just that to most persons of the world but before recent times it was not known that the dark areas were produced by the violent impacts of asteroids hitting the moon many hundreds of million years ago. These primordial impacts on the lunar surface played a large part in reshaping the moon’s appearance and could explain why there are two large protrusions on the surface of the moon. “New analysis reveals that shock waves from some of the moon’s early asteroid impacts traveled through the lunar interior, triggering volcanic eruptions on the moon’s opposite side. Molten magma spewed out from the deep interior and flooded the lunar landscape” (Than, 2006). The cooled magma created the familiar dark areas which are termed ‘lunar seas.’ These dark areas unite to form the ‘face’ of the moon. The Man in the Moon’s eyes have been labeled “’Mare Imbrium’ and ‘Mare Serenitatis’. The nose, ‘Sinus Aestuum’ and the mouth, which appears to be smiling, is a combination of the ‘Mare Cognitum’ and ‘Mare Nubium’” (Heiken et al, 1991). The Earth’s sky appears to be blue because its atmosphere diffracts light in such a way that produces this familiar illusion. The moon has no atmosphere therefore its sky appears as it actually is, black. The gravity on the moon is much less (one-sixth) than on Earth. An illustration of the difference could be seen when U.S. astronauts were bouncing around on the moon during the Apollo missions beginning on July 20, 1969. The second man on the moon, Edwin (Buzz) Aldrin hit a golf ball that he said traveled “miles and miles” (Heiken et al, 1991). Located about a quarter-million miles from Earth (an average of 238,857 miles), the moon rotates around the Earth once every 27.3 days. Because the same face of the moon appears to Earth-bound gazers, a common misperception is that it does not spin on its axis as does the Earth. “Both the rotation of the moon and its revolution around Earth takes 27 days, 7 hours, and 43 minutes. The moon takes as much time to rotate once on its axis as it takes to complete one orbit of Earth” (Hamilton, 2005). Precisely how the moon was formed has been a long-standing mystery and still remains just a theory. However, for the past quarter-century, the majority of scientists have agreed upon a likely scenario. According to the general consensus opinion, about four and a half billion years ago, a planet or asteroid about the circumference of Mars collided with the Earth, striking it indirectly. The impact sent the Earth spinning and the part of the Earth’s crust that was disengaged from the impact began circling the Earth much in the same way Saturn’s rings revolve around that planet. This material now caught in Earth’s gravitational pull was made up of both the upper layer of the Earth and the object that struck it. Eventually, this material coalesced into one large mass, the moon (Heiken et al, 1991). This is a viable theory but not the only one. Some scientists theorize that the moon was created by an indefinite means far from Earth then became trapped in a gravitational orbit around the Earth when it passed close by. A hypotheses closely related to the ‘impact theory’ is that “gravitational interactions between the Earth, the Sun, and other developing planets simply tore Earth apart and the moon formed from this debris” (Britt, 2001). Still, most scientists suggest the ‘impact theory’ as being the most probable. Though such a cosmic event was common in the early stages of the solar system, it is very improbable in its present stage of development. “The last stages of planetary accumulation were very violent. An event of this type within 100 million years of the birth of the solar system is not rare at all” (Britt, 2001). The combination of the Sun and moon’s gravitational pull on the earth causes the ocean’s tides. The term ‘tides’ describes the “alternating rise and fall in sea level with respect to the land. Tides are the periodic rise and falling of large bodies of water” (Cooley, 2002). The moon exerts more gravitational influence (56 percent) on the Earth than does the Sun. Much the same as magnets attract, the moon and Earth attract each other thus creating tides. The force of the moon’s influence attempts to draw the Earth closer which has little effect on the solid regions but is able to move the liquid portion of the Earth. Because water is constantly in motion, the Earth cannot control it therefore the moon’s gravitational pull is able to move it. Every day on Earth, two high and two low tides occur. Oceans are in constant motion, alternating from high to low tide then back again with approximately 12-hour intervals between high tides. Tides do not cause waves which are the result of currents and wind. The moon’s gravitational pull causes the oceans to ‘bulge out’ towards the current location of the moon and the opposite side of the earth as well. Because the Earth is pulled in the direction of the moon, water on both sides of the Earth is affected. On the near side of the moon, the water itself is pulled and on the other side, the Earth is being pulled away from the water. As the Earth, moon and Sun interact in this gravitational dance, ocean levels ebb and flow. “As the moon travels around the Earth and as they, together, travel around the Sun, the combined gravitational forces cause the world’s oceans to rise and fall. Since the Earth is rotating while this is happening, two tides occur each day” (Cooley, 2002). Life on Earth first inhabited the seas. Many species such as crustaceans, seaweeds, fish and worms were abandoned to the shores as the rising tides receded. While most did not survive the harsh, forbidding alien land, some managed to adapt to their temporary existence on land during low tide and over millions of years of evolution, fewer still were able to adapt to living exclusively on the shore rather than the sea. “Species adapted to the temporary endurance of dry land developed, and the continuing pressure of competitors saw to it that there was survival value to be gained in developing the capacity to withstand dry-land conditions for longer and ever-longer periods” (Bauman, 2006). Without the moon’s influence on Earth’s tides, this evolutionary adaptation likely would not have occurred because there would have been no reason for life to emerge from the seas. The moon has not only influenced the culture of mankind, it is likely responsible for the very existence of humans in the first place. The subject of stories, myths and wonderment, the moon has directed the course of humans from the earliest beginnings. It is much more just a large light in the night sky that inspires romantic moonlit walks along the beach. It is the giver of life to no less a degree than the Sun or the Earth itself. Works Cited Bauman, Deron. “The Importance of the Moon.” (2006). October 7, 2007 Britt, Robert Roy. “24 Hours of Chaos: The Day The Moon Was Made.” Space.com. (2001). October 7, 2007 Cooley, Keith. “Moon Tides.” (2002). October 7, 2007 Hamilton, Rosanna L. “The Moon.” Solar Views. October 7, 2007 Heiken, G.; Vaniman, D.; French, B. (Eds.). Lunar Sourcebook: A User’s Guide to the Moon. New York: Cambridge University Press, 1991. Miles, Kathy A. & Peters, Charles F. II. “What if the Moon Didn’t Exist?” Starry Skies. (2001). October 7, 2007 Than, Ker. “The Origins of the Man in the Moon.” Space.com. (2006). October 7, 2007 Read More