Could There Be Life in Other Planets - Term Paper Example

The search for life on other planet in the universe is the central theme of scientific activity in this century. While humans have been trying to figure out how humans came to the earth, they have also been trying to understand the likelihood that other planets have given life to earth. Until mid-1195 it was believed that our solar system might be unique as far as the presence of Jupiter is concerned (Léger et al., 1996). This was because of the lack of discovery of giant planets. By fall 1995 discoveries pointed out to the existence of giant gaseous plants and a large diversity among planetary systems. Before attempting to determine of life exists on other planets, it is essential to first understand the meaning of life and intelligent life. Life can be defined as "a condition that distinguishes organisms from inorganic objects and dead organisms, being manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally" (Borghino, 2008). “Intelligent life” is the condition in which a particular form of life has also developed a technology level comparable to ours. Spiritualists such as Rutler and Moniot (1997) believe that when people ask if there is life on other planets, it is an inner quest to know what is life and what is the nature of our being. Life, according to Kleefman (1997), means carbon based organic life forms that need liquid water to exist and hence not all planets are capable of sustaining life. There are more than 250 extrasolar planets and more are being discovered (Whethington, 2007). BBC (2009) says that Mars, Titan and Europa are likely to have life as astronomers believe that life has a good chance of evolving where conditions are right. While some argue that life may exist on other planets but the existence of intelligent life is doubtful had intelligent life existed on other planets, they would have visited Earth and communication signals could have been detected (UFO Casebook, 2009). Spiritualists also raise the question of evolution and creation. If water is found on any –planet, it indicates life (Moore, 2005). When NASAs rover Opportunity discovered evidence that Mars had once been wet, people became excited because where there is water, there may be life (Bostrom, 2008). However, life in Mar was dismissed in 1976 (Begley, 2006) but some scientists still argue that they have detected living microorganisms in the soil of Mars (Begley, 2006a). A poll of 250 scientists who study the planet, revealed that only one-quarter thought that life could exist on Mars (The Economist, 2005). Scientists have tried to evidence life by remote sensing but it remains a challenge. If based on organic chemistry, life requires the presence of liquid water. The raw material of the primitive atmosphere of terrestrial planets is expected to be fully oxidized carbon. Now if there is life on other plants it would imply massive reduction of oxidized carbon due to photosynthesis and the release of oxygen (Léger et al., 1996). Oxygen is highly reactive with reducing planetary rocks and hence the authors conclude that massive presence of oxygen denotes could be a strong indication of life on other planets. Arnold et al., (2002) however, feel that oxygen is not a universal by-product of biological activity as demonstrated by the existence of anoxygenic photosynthetic bacteria. There are signs of stellar light transformation into biochemical energy. This is evident from the plant surface colour from vegetation. This is a more robust biomarker than any biogenic gas such as oxygen. Now it is necessary to test if terrestrial vegetation can be detected remotely. This is possible if the earth is observed with a significant spatial resolution. For the bioprocesses, something more than mere oxygen is necessary. For instance, the presence of water and correlated with seasonal variations could provide more insight than simply oxygen whether life exists on other planets. Water and hence clouds and rain are essential for growth of vegetation, other planets with a low cloud cover and a corresponding high vegetation index are highly unlikely. According to Cartwright (2008), presuming that the earth is the only inhabited planet, is absurd. In our galaxy alone there are billions of planets. Earth is not even situated in the middle of our galaxy. Only the planets that contain water can have life. Mars does have ice/water and Europa is also believed to be having water hidden under its surface. In these two planets signs of past life could be found or perhaps signs of actual living primitive life-forms alive within the ice and water. The possibility of advanced life in our galaxy is remote but there is possibility that life does exist on other planets not in our solar system. However, astronomers believe that the universe is formed of hundreds of millions of galaxies which contain hundreds of millions of stars. The possibility of life on other planets cannot be ignored, according to the Pope (Daily Mail, 2008). Astro biology has made significant advances in recent years. “Panspermia” is based on the established belief that “life comes from life”. Life on earth originated from life and this theory has been postulated by many scientists. In 1978, the presence of icrofosils resembling yeast cells and fungi was rediscovered (Joseph, 2009). Other biological activity like photosynthesizing has taken place in these ancient rock formations and this is evident from the presence of high carbon contents. Life on Earth is believed to have existed from the time the Earth was formed from the debris. Micofossils were also detected and our sun and solar system was also formed from the nebular debris. Spores and bacteria can survive for millions of years and also survive the hazards of space. They could not have acquired these abilities if their ancestral experience had been confined to Earth. Since only life can produce life and since life on Earth came from elsewhere, it suggests that life does exist on other planets. Crick and Orgel (1972) contend that organisms were deliberately transmitted to the earth by intelligent beings on another planet. This is known as Directed Panspermia. Darwin and many other biologists had concluded that since spontaneous generation on Earth is not taking place, life must have evolved on Earth long ago when conditions were more favourable. Some other scientists drew another conclusion that if life does not evolve from terrestrial non-living matter now, then it may never have existed. They, hence, concluded that life has reached the earth as an infection. Kelvin suggested that the first organisms reached the earth in a meteorite but for any known type of radiation-resistant spore, the radiation during the journey from another Solar System to the Earth would be so high that it would not be able to sustain itself. Hence the possibility of massive objects that escape the solar system and come to another planet is small. These explanations against the “infective’ theories of origin of life were argued to be rejected because they only transfer the problem of origins to another planet. Such theories cannot be summarily rejected because there may be another type of planets on which the origin of life may be more probable than our own. The first generation of stars that were formed from light elements, are unlikely to have been accompanied by planets (Crick & Orgel, 2000). At the same time, it is probable that planets not unlike the Earth thousands of years before the formation of our own Solar System. The time that elapsed between the life on Earth and the development of our own technological society, suggests that technological societies existed elsewhere in the galaxy even before the earth was believed to have been formed. It can thus be assumed that a primitive life form was deliberately planted on earth by a technologically advanced society from another planet. Darwin’s theory of evolution gave rise to controversies. He described the process in the evolution and said that many more individuals of each species are born than that can survive. His theory contradicted the biblical theory of life formation. Stanley L Miller came up with an experiment when he zapped a flask filled with methane, ammonia, hydrogen and water vapor with an electrical charge. The vapour condensed and drained back into a water reservoir. Within a week, the water was filled with organic compounds, including amino acids, which are essential to sustain life (Hughes, 2002). This suggested that universe was teeming with life. It was subsequently found that organic matter such as amino acids could be created from inorganic material with the help from natural energy source such as lightning. This suggests that life does not exist elsewhere in the universe. However, according to Richard Dawkins, many complex and organized structure exist in the universe such as waves, crystals, snowflakes, Saturns rings. Life on earth began soon after the earth had cooled and after it gained some respite from the constant bombardment of the material that formed the planets. This implies that life’s creations were not too astronomical and that life exists on other planets. Mars and Venus were expected to contain life and it was found that Venus contained a hellish environment with a thick, poisonous atmosphere. This atmosphere retained so much of the sun’s warmth that any organism that survived the sun’s poisons would be baked in an instant. Mars is benign to life. It has polar ice caps but it does not have water and oxygen. If life does exist on Mars it is hidden and isolated. Jupiter and Saturn are gaseous, giant planets and do not seem likely to contain or maintain life but Moon’s of these planets could contain life. Jupiters Europa and Saturns Enceladus are both icy moons and they generate reservoirs of liquid water beneath the icy surface. Previously sun was considered to be essential for life but hydrothermal vent communities thrived in total darkness. Many scientists thus started believing that life can start in the ocean’s hydrothermal vent environments. Life can also begin in little, ice-encased pockets of liquid water that can remain in the ice even when the ice’s temperature reaches minus 60 degrees Fahrenheit. It can trap impurities including organic impurities. Thus life can exist in different environments and hence it increases the chances that life can start on different planets. Many associate the presence of UFOs with life on other planets. Slick (1995) contends that the UFO phenomenon is occultic in origin and is demonically based. Many claim to have been abducted by the UFOs. According to the author, those that see or have been abducted by UFOs are themselves involved in occult practices and in no way does it prove that life exists on other planets. Scientists contend that photosynthesis, the process that converts sunlight, carbon dioxide and water into plants is merely 2.4 billion years old while life can be traced back to 3.5 billion years (Anonymous, 2009). Hence before photosynthesis, energy must have come from something else. Besides, it is also believed that whatever powered the life on Earth must have also powered life on other planets. The discovery of hydrothermal vents has caused great excitement. The bacteria that extract the thermal energy and thus form the base of the of the hydrothermal ecosystems food chains, might be same as the bacteria that lived before the photosynthesis. However, chemical reactions require oxygen as one of their components. Hydrogen is also used as a source of chemical energy and hydrogen can be found in abundance in the vents. Photosynthesis uses light to split water into hydrogen and oxygen, and hydrogen then combines with carbon dioxide to create energy-rich carbohydrate compounds. Now, since hydrogen is readily available, an energy source such as light or oxidation may not be needed to keep the eco system going. Thus it is likely that life form does exist on other planets. So far no radio signals have been received which could have been transmitted by any extra terrestrial civilization. The earth has not received any one from space and The Search for Extra-Terrestrial Intelligence (SETI) has been employing powerful telescopes and data mining techniques without any evidence of any life elsewhere (Bostrom, 2008). Different opinions and researches suggest that since oxygen is not essential and since hydrothermal vents have been discovered, life on other planets is likely. While there are a lot of debates about mars having life, and since it is believed that life comes from another life, it is argued that life on Earth came from another planet. All these discoveries lead one to believe that there could be life on other planets although there is no evidence yet. 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(1997). Is There Life on Other Planets? What Does This Mean for Revealed Religion? Retrieved online 16 November 2009 from http://www.columbia.edu/cu/augustine/arch/frear/rutler97.htm Slick, M. J. (1996). Does the Bible tell us if there is life on other planets?. Retrieved online 16 November 2009 from http://www.carm.org/christianity/bible/does-bible-tell-us-if-there-life-other-planets The Economist. (2005). Science and Technology: Life on Mars!!! (Not); Astrobiology. London: Mar 5, 2005. Vol. 374, Iss. 8416; pg. 88 UFO Casebook. (2009). Could There be Life on other Planets? Retrieved online 16 November 2009 from http://www.ufocasebook.com/2009c/couldtherebe.html Whethington, S. (2007). Could We Detect Plants on other Planets? Universe Today. Retrieved online 16 November 2009 from http://www.universetoday.com/2007/12/05/could-we-detect-plants-on-other-planets/ Read More