Extraterrestrial Life

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Humans have always been wildly fascinated about the possibility that extraterrestrial life could, does currently, or has existed elsewhere in the universe. This is a subject that has been questioned by humankind for at least 2000 years. Lucretius, a Roman poet from the first century B.C., had suggested that “just as life originated by spontaneous chemical interactions on Earth, ‘we must acknowledge that such combinations of other atoms happen elsewhere in the universe to make worlds such as this one…. there are other worlds in other parts of the universe, with races of different men and different animals (Hobson quoting Lucretius, 2006).’” It is thought by many anthropologists that the discovery of life elsewhere in the universe would completely change our world’s sense of self. We would no longer be alone; our understanding of existence would change exponentially.

The Copernican view, suggests that Earthlike conditions elsewhere should lead to intelligent life elsewhere. This is based on the premise that the principles of nature are the same everywhere in the universe. Scientists have estimated that there are about 400 billion stars in the Milky Way galaxy. Observations have shown that about 50% of the stars in our sun’s area, are not a single body of burning gases, but multiple bodies of burning gases. The ideal conditions for planet formation do not occur in the clusters of stars, which appear to be a single star. Planet formation is most likely to occur in single body stars. Of the single stars, there are many of them that are not good for planet formation in that they burn too brightly, and are entirely too massive; ultimately, they burn up their fuel fast, not allowing enough time for planets to form. Stars that are much smaller often burn very dimly. For life to occur, a planet would have to orbit very close to the star, to ensure that the climate is warm enough for life to be sustainable. When planets orbit a star, the star wobbles slightly. This is because of the gravitational pull that the planet exerts on the star. Astronomers can detect this wobbling. They very carefully measuring and tracking the position of the star. It can also be detected by measuring the frequencies of the waves of light that the star gives off. In a 1953 experiment by Stanley Miller and Harold Urey, it was shown that many amino acids and nucleic acids are easily created. The pair used water vapor, hydrogen, methane, and ammonia in a sealed jar, and then put it in contact with liquid water. To stimulate volcanic activity, they heated the mix. For lightening, they sent sparks through the mixture. With in a few days, the liquid water had turned brown. Upon analysis, it was shown that a variety of amino acids and nucleic acids had formed. These are also the building blocks of life. DNA chains are formed when many amino and nucleic acids link to together into strings, which are then developed into a double helix. Since this experiment, it has been learned that the early atmosphere was probably comprised of carbon dioxide, nitrogen, and water, rather than the four used in the experiment. When these three ingredients were used with the same and similar conditions, many more amino and nucleic acids formed. As long as these three ingredients are gaseously combined, chemical reactions occur that create the building blocks of life. Although life developed immediately after conditions permitted it, life stayed in a stagnant state of a simple-single-celled bacteria form for about 2 billion years. At some point during the first billion years, some of the cells developed the ability to absorb water, incorporate the water’s hydrogen atoms into the cell’s structure and then to excrete the oxygen atom. This changed the global climate to an oxygen rich atmosphere. Biological convergent properties are traits that tend to evolve again and again. This can be better understood by looking at wings....
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