Essay On Forces That Drive Life On Earth
One major force that drives life on the planet is the lunar pull of the moon that causes tides. It is said that around 4.5 billion years ago, when our earth was still a molten mass, another molten mass was thrown into space, and this coalesced into what we know today as the moon. The earth then was already cooling, and had an ocean, but no veritable life was to be found in it. During this time, the moon was about half as distant from the earth as it is now, such that the lunar tides were more extreme and powerful. The moon is receding from the earth at a rate of 1.5 inches annually, and so the own spin rate of the earth is slowing down. As this is happening, an enormous amount of energy is poured into the earth’s oceans every year. This energy then causes the oceans’ tidal movement, bringing heat and nourishment from the equator to the poles. Also, this caused glaciations which in turn helped bring about the evolution of many species. When the species evolved, eventual glaciations also brought about migration of species and the development of even more species. These tidal oscillations are also said to have brought about the salty and low tidal conditions that caused the development of protonucleic acids for the formation of life (Dominey, 2009). Tidal forces are the secondary effects of gravity, and of course, the earth also exerts some forces over the moon, being its only satellite.
As the moon continues to recede from the sun, the rotation of the earth is slowing down. Daytime on earth is thus being lengthened by about two minutes every century. Also, the earth exerts its own gravitational pull on the moon. The concept of the Roche Limit is that of the distance of a celestial body (which is held by its own gravity), at which it will disintegrate due to the gravitational forces of the main body. In this case, the Roche Limit is the distance between the earth and the moon at which the moon will disintegrate due to the excessive forces exerted by the earth on it. If there should be a possibility of the moon coming too close to the earth in the future, then the Roche Limit may be approached (Marine Bio, 2015).
On the other hand, if the moon continues to recede from the earth as it has been doing, the tides would be a fraction of what they are today and the rotation of the earth would definitely slow down, making the days a lot longer than what they are today. Scientists say that in four million years, one day will be about 47 current earth-days long. The pull of the moon would no longer be influential on oceanic currents, and the natural feeding habitats of many marine creatures would disappear (Science Blogs, 2013). When this happens, marine life may disappear altogether, wreaking havoc on the food chain of the earth. For one, if humans can no longer partake of fish, then there may serious conditions and illnesses that may abound. If the larger sea creatures have no more smaller fish to eat, many more species will die out. The tides and currents would not ebb and flow as they used to, and the oceans would be very different from what they are today.
Thus the gravitational forces of the moon are essential to life on earth. Their life-giving effect is seen in the tides and currents around the world that bring heat and food to parts of the oceans that otherwise would have nothing. Many creatures on earth vital to the food chain benefit from these forces. Should these forces weaken, life on earth would change for the worse.
Dominey, B. (2009). Without the Moon Would there be Life on Earth? Retrieved from: http://www.scientificamerican.com/article/moon-life-tides/
Marine Bio. (2015). Currents and Tides. Retrieved from: http://marinebio.org/oceans/currents-tides/
Science Blogs. (2013). The Top Five Things if We Didn’t Have a Moon. Retrieved from: http://scienceblogs.com/startswithabang/2013/08/08/the-top-5-things-wed-miss-if-we-didnt-have-a-moon/