OUR PLACE IN THE UNIVERSE
The earth is the fifth largest of the eight planets and is the third from the sun. It is located on a disc shaped galaxy known as the Milky Way, together with eight other planets, with the common denominator: the sun. The Milky Way is so named due to its appearance, with the name adopted as a direct translation of Latin, via lactea. The planet earth itself is located about two thirds from the center of the Milky Way, which is only one of many galaxies in space appearing to the inexperienced eye as ordinary stars (Glendenning pg 5).
The Milky Way is estimated to be at least ten billion years old, which makes it hard to comprehend not only the vastness of the galaxy, but also the age of various heavenly bodies. Galaxies are usually described according to their apparent shapes and sizes; determined by the number of stars within each one. The smallest galaxies are usually referred to as Dwarf galaxies because they hold fewer stars within their system. Spiral galaxies on the other hand, are disc shaped and usually have dusty curving arms, and it is under this category of galaxies that the Milky Way falls. Further, there are those that lack a regular shape and are therefore referred to as the irregular galaxies (Tucker and Hefner pg 15).
Compared to the other nine planets within the galaxy, only planet earth has a climate capable of sustaining life. This is due to the fact that not only does it have a breathable atmosphere which contains oxygen, but it also has a temperate climate, fit for the survival of living things. In addition, the fact that it is situated about 150 million kilometres from the sun, as well as its size, ensure that it is neither too hot nor too cold. Even though Mars exhibits some similar features such as the availability of air, the cold temperatures would make it difficult for living things, particularly humans to survive. This temperature difference is essentially due to the planet’s positioning within the solar system. Planets which are too far from the sun like Neptune or Uranus are extremely cold while planets that are too close to the sun, like Venus are extremely hot. These extremes make then inhabitable and make them incapable of supporting life, more so human life.
Due to the lack of gravitational pull in space, where the galaxy is located, the planets as well as stars usually appear as if they are suspended in air. The easy view of the sun, moon, and other planets, human beings have been creating stories of what they see in the sky. Many questions have been asked about the existence of the system, but the answers have not been satisfactory. Studies have found that the earth not only rotates, but also revolves around the sun, and as such does not have a fixed point of stability in the center of the universe. This rotation and revolution are what bring about the different seasons, which serve to further make it habitable.
Larger telescopes have revealed that stars are far away in space. Scientists have also proved that the Milky Way is not the only one in the universe, but there exists many other galaxies. Since light travels at extremely high speed, when we look at a star we are able to see it, but it appears as it was long ago when the light by which we now see it left it.
The nearest neighbor from the earth is the moon. The moon is mostly made up of rock and has no water bodies like earth. The other close neighbor to earth is the planet Venus, which appears to be having white clouds. They are fundamentally droplets of sulfuric acid floating in a thick atmosphere consisting of carbon dioxide. Planet Mercury, which is the closest to the sun, is barren and appears to have no air or clouds and looks like a big rock. The surface temperature swings between 800 degrees to minus 300 degrees varying during the day and night.
References
Glendenning N. K. Our Place in the Universe. N Y. World Scientific. 2007.
Matthews C.N. Tucker M.E. Hefner P. When Worlds Converge: What Science and Religion Tell Us about the Story of the Universe and Our Place in It. Open Court Publishing. 2001.
(Editor Comments Ratings)
I rate the editor’s comment at 5. The editor has some solid points on the article when he/she talks about the flow, the short sentences and repetition. On the grammatical aspect I noticed some issues such as errors in the punctuation within sentences and wrong use of vocabulary, which the editor overlooked. Generally the article is informative and straight to the point which I believe is one of its strongest points.
