Life in Outer Space Essay

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Life in Outer Space The answer to the above question is I don't know. This essay is not an essay of answers because nobody knows the answer. What I want to do is speculate. My speculation will be controlled and based on the knowledge we have at present. Like all science, everything I say in this essay could be proved wrong by a new theory or discovery tomorrow. However, the path that we follow will be full of interesting ideas that, I hope, will stimulate the reader. The reason I talk about extraterrestrial life is because there is strong evidence that all life on this planet has a common origin. Chemically and genetically there are evolutionary links between all organisms that more or less…show more content…
That is actually very difficult. The one I will use for this essay is as follows. A living organism is a system that can interact with its environment, exchanging material with the outside, and capable of reproducing itself. Essentially, this is a chemical definition of life. Molecules pass into the organism and are built up to complex molecules distinctive of the organism by a series of chemical reactions. Waste products from this process are passed back out again. Many people believe that life involves something else apart from chemistry. This is a piece of speculation that I will ignore since I know nothing about it. Organic Chemistry ================= The above chemical definition of life actually imposes severe limits on where life can be expected. Life on Earth is made up of complex molecules based on Carbon. This is no accident. Carbon is the only atom capable of forming large complex molecules. The chemistry of carbon compounds is called Organic Chemistry. The chemical reactions of life are subtle and complex. Let us look at the conditions necessary for complex chemical reactions to occur. In nature, matter is found in three states: gas, liquid and solid. In solids the molecules are held together in fixed positions relative to each other. In liquids, the
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