One question should be asked what is life Life is an organic form composed of carbon that cannot do without water to exist. One thing man is certain about is that, earth is the only planet that can support life. He is not sure about other planets. For a planet to support life it must meet a certain condition it must be a habitable place (Kleefman, par 1-3). However, it is known that there are some organisms or creatures which can survive in harsh environments here on earth for example, where there is extreme cold temperatures, little water or air (oxygen).These kind of environments are said to be found on other planets (University Corporation for Atmospheric Research, par 1). The question still remains can life really exist on other planets apart from the earth
Life on Saturns Moon
When scientists announced that they had discovered life on the Saturns moon (Titan), it raised so many questions. Even though the moon is characterized by extreme cold temperatures making it impossible to have liquid water, they continue to say that exotic creatures could be living in the liquid lakes of methane and ethane which are found there. The life was discovered by a space craft called Cassini. Another development found is that, hydrogen on the surface of the moon is somehow depleting. It is expected that, the hydrogen produced in the atmosphere should be accumulating on the moon but that is not the case, hence this show that there could be something consuming it (Malaysia Sun, par. 1-7).
Studies continue to show some interesting chemistry happening on the moon (Malaysia sun, par 8). NASA, the US space agency has come out to support that, there could be actually some forms of primitive life on Titan. Titan is the only planet body that has liquid bodies on its surface apart from the earth. According to NASAS latest findings, the moon could actually be supporting primitive forms due to its dense atmosphere (Techtree news staff, par 1-4). These primitive life forms could be different from the earths water based life forms since the findings show that the former may be using hydrogen to survive. The evidence shows that these life forms could be based on methane and thus this kind of environment is not conducive for us humans (Techtree News Staff, par. 5).
Life on mars
In the year 1996, a historical announcement was made by NASA. They announced that they had found microscopic life, an ancient one and had been fossilized. The scientists got it from a meteorite known as the Martian. The meteorite had travelled from the space over thousands of years before it reached the earth but it was discovered in the year 1984 by NASA scientists at Johnsons Hills ice field. There are so many factors that led the scientists to conclude that there could be an ancient life on Mars (Mars News, par. 1-4).
The first evidence is the carbonate globules which were found on the meteorite. The density of the carbonate and how it was patterned somehow relates to how bacteria of terrestrial nature operate. Also present on the meteorite were organic substances or compounds that are known to be created by bacteria. The most convincing evidence found on the meteorite was the presence of structures that resembled some worm like creatures. When these creatures are compared to terrestrial bacteria, the former appear to be much smaller (Mars News, par. 4- 8).
Recently, some evidences were found to confirm the above claims. Two rocks from the planet mars have been found and they also contain structures indicating the existence of some life forms on mars. These two meteorites called Nakhla was found in Egypt in the year 1991 and the other one called Yamato was discovered in Antarctica in the year 2000. A foot print could be observed on Nakhla (MCNBC, par 3, 4, 8).
Conditions that built life on earth
The beginning of life was marked by the solar system development. The solar system is said to be 4.6 billion years old. Although life on earth developed as a result of carbon rich molecules, the rest of the planets and the sun do not have these molecules. At the beginning, the earth was mainly molten rock which slowly underwent cooling through the process of heat radiation into space. The original atmosphere was mainly made up of water, carbon monoxide and carbon dioxide, nitrogen, hydrogen, hydrogen chloride, oxygen and other gases from the molten rock. The atmosphere at that time was very steamy, rich in water which came from minerals that were hydrated at the time and some impacts from other comets (Rawlings, par. 1- 5).
When the earth was still cooling, a torrential rain came down and since the earths surface was too hot, the rain was converted into steam immediately. It then turned into water which was super heated that later collected into seas and oceans which were also warm and hot. These seas and oceans formed above and around crystal rocks which were also cooling at that time, forming sediments. Some asteroids and comets would hit the planet once in a while, ending up re-melting the crystal rocks, making the oceans to go back to their original state of hot mist. However, between 0.2-0.4 billion years, a rocky crust which was stable formed (Rawlings, par. 6).
When the comets and meteorites ceased to bombard the earths surface, the anaerobe microbes started to move and spread to other areas which were wet. They multiplied and adapted to new environment. Some of these microbes got adapted to living on land even though they were single celled. They multiplied 600 times in the earths atmosphere and it is believed that, the amount of methane at that time would have had stronger green house effect more than today but what prevented it was the suns light, which was somehow dimmer approximately 20 at that time(Rawlings, par. 10). However, there were very high temperatures at that time which led to the existence of humid conditions. This was made possible by a water cycle that was very active then. This humid condition was very favorable to methanogens.This active water cycle made the weathering of rocks to continue at a high rate which happened in the continents that existed then. This prevented these continents from using up enough carbon dioxide thus reducing the concentration of the gas in the atmosphere to the level of methane. Despite of this, methane is useful in forming hydrocarbons even though complex ones which undergo condensation to form dust like particles. These particles create a haze of high attitude that helps in absorbing the incoming sunlight thus re radiating it back to space reversing its effects. This prevents the green house effect (Rawlings, par. 10).
Before 1.9 billion years elapsed, large amount of the earths heat must have been removed from its core due to the increasing number of magma plums. It was expected that cooling conditions would have led to formation of more oceanic crust which contained less nickel that was supposed to be used by methanogenic bacteria to form energy and methane by converting food but this did not happen due to high temperatures. Less methane was produced by these methanogens as they could not get enough food. Methane would have been useful in removing oxygen from the atmosphere but since it was in small quantity, the amount of oxygen increased leading to the event of great oxygenation that took place between the 2.2-2.3 billion years (Rawlings, par. 11).
Between the years, 2.1-26 billion years, the anaerobes mutated to form purple bacteria of aerobic nature. These bacteria could feed on molecular oxygen and carbohydrates to produce water and carbon dioxide. There also emerged a symbiosis relationship between different microbes and they achieved this through ingestion that was devoid of digestion (Rawlings, par.16). These microbes used cellular membrane to form nuclei through the process of endosymbiosis and these membranes were supposed to contain the DNA. Some bacteria which were heat and acid resistant may have come into contact with other types of bacteria to form cilia or flagella. It is possible that some of these bacteria may have merged with purple bacteria which used to breathe oxygen. This merging resulted into the formation of the mitochondria within them. Others merged with microbes that breathed in hydrogen to form other organelles. It is also possible that aerobic microbes merged with bacteria of photosynthetic nature to form chloroplasts and plastids, leading to the formation of green algae and other plant cells that are precursors of todays ones. At the end, the microbes which were formed, adapted to the new environment hence they diversified and multiplied in numbers (Rawlings, par. 17).
The photosynthetic bacteria continued to produce oxygen which was absorbed by iron found in the oceans. This led to an ancient rain that was characterized by particles which were minute and rusty. These particles are the ones which formed the ocean floors that are found today. The amount of oxygen increased leading to its conversion to tri atomic form which rose up and came to be known as the ozone layer. The aerobic bacteria continued to multiply but the anaerobic ones continued to die (Rawlings, par. 18).
Later, geologic and weather processes led to the decrease of carbon dioxide from the atmosphere. The huge number of photosynthetic microbes which produced so much oxygen, also led to the decrease of carbon dioxide and methane in the atmosphere reducing the green house effect on the earths surface cooling it completely. This continued until the levels of carbon dioxide and methane rose leading to a melt down although the microbes should have survived to form life forms which were multi cellular such as plants, fungi and animal like microbes (Rawlings, par. 19- 20).
In conclusion, it has been observed that, there could be life forms on other planets apart from the planet earth but studies are still continuing. One thing that has also emerged is that, these life forms are very different from the earth ones and this could be explained by different environments that characterize different planets.
Life on Saturns Moon
When scientists announced that they had discovered life on the Saturns moon (Titan), it raised so many questions. Even though the moon is characterized by extreme cold temperatures making it impossible to have liquid water, they continue to say that exotic creatures could be living in the liquid lakes of methane and ethane which are found there. The life was discovered by a space craft called Cassini. Another development found is that, hydrogen on the surface of the moon is somehow depleting. It is expected that, the hydrogen produced in the atmosphere should be accumulating on the moon but that is not the case, hence this show that there could be something consuming it (Malaysia Sun, par. 1-7).
Studies continue to show some interesting chemistry happening on the moon (Malaysia sun, par 8). NASA, the US space agency has come out to support that, there could be actually some forms of primitive life on Titan. Titan is the only planet body that has liquid bodies on its surface apart from the earth. According to NASAS latest findings, the moon could actually be supporting primitive forms due to its dense atmosphere (Techtree news staff, par 1-4). These primitive life forms could be different from the earths water based life forms since the findings show that the former may be using hydrogen to survive. The evidence shows that these life forms could be based on methane and thus this kind of environment is not conducive for us humans (Techtree News Staff, par. 5).
Life on mars
In the year 1996, a historical announcement was made by NASA. They announced that they had found microscopic life, an ancient one and had been fossilized. The scientists got it from a meteorite known as the Martian. The meteorite had travelled from the space over thousands of years before it reached the earth but it was discovered in the year 1984 by NASA scientists at Johnsons Hills ice field. There are so many factors that led the scientists to conclude that there could be an ancient life on Mars (Mars News, par. 1-4).
The first evidence is the carbonate globules which were found on the meteorite. The density of the carbonate and how it was patterned somehow relates to how bacteria of terrestrial nature operate. Also present on the meteorite were organic substances or compounds that are known to be created by bacteria. The most convincing evidence found on the meteorite was the presence of structures that resembled some worm like creatures. When these creatures are compared to terrestrial bacteria, the former appear to be much smaller (Mars News, par. 4- 8).
Recently, some evidences were found to confirm the above claims. Two rocks from the planet mars have been found and they also contain structures indicating the existence of some life forms on mars. These two meteorites called Nakhla was found in Egypt in the year 1991 and the other one called Yamato was discovered in Antarctica in the year 2000. A foot print could be observed on Nakhla (MCNBC, par 3, 4, 8).
Conditions that built life on earth
The beginning of life was marked by the solar system development. The solar system is said to be 4.6 billion years old. Although life on earth developed as a result of carbon rich molecules, the rest of the planets and the sun do not have these molecules. At the beginning, the earth was mainly molten rock which slowly underwent cooling through the process of heat radiation into space. The original atmosphere was mainly made up of water, carbon monoxide and carbon dioxide, nitrogen, hydrogen, hydrogen chloride, oxygen and other gases from the molten rock. The atmosphere at that time was very steamy, rich in water which came from minerals that were hydrated at the time and some impacts from other comets (Rawlings, par. 1- 5).
When the earth was still cooling, a torrential rain came down and since the earths surface was too hot, the rain was converted into steam immediately. It then turned into water which was super heated that later collected into seas and oceans which were also warm and hot. These seas and oceans formed above and around crystal rocks which were also cooling at that time, forming sediments. Some asteroids and comets would hit the planet once in a while, ending up re-melting the crystal rocks, making the oceans to go back to their original state of hot mist. However, between 0.2-0.4 billion years, a rocky crust which was stable formed (Rawlings, par. 6).
When the comets and meteorites ceased to bombard the earths surface, the anaerobe microbes started to move and spread to other areas which were wet. They multiplied and adapted to new environment. Some of these microbes got adapted to living on land even though they were single celled. They multiplied 600 times in the earths atmosphere and it is believed that, the amount of methane at that time would have had stronger green house effect more than today but what prevented it was the suns light, which was somehow dimmer approximately 20 at that time(Rawlings, par. 10). However, there were very high temperatures at that time which led to the existence of humid conditions. This was made possible by a water cycle that was very active then. This humid condition was very favorable to methanogens.This active water cycle made the weathering of rocks to continue at a high rate which happened in the continents that existed then. This prevented these continents from using up enough carbon dioxide thus reducing the concentration of the gas in the atmosphere to the level of methane. Despite of this, methane is useful in forming hydrocarbons even though complex ones which undergo condensation to form dust like particles. These particles create a haze of high attitude that helps in absorbing the incoming sunlight thus re radiating it back to space reversing its effects. This prevents the green house effect (Rawlings, par. 10).
Before 1.9 billion years elapsed, large amount of the earths heat must have been removed from its core due to the increasing number of magma plums. It was expected that cooling conditions would have led to formation of more oceanic crust which contained less nickel that was supposed to be used by methanogenic bacteria to form energy and methane by converting food but this did not happen due to high temperatures. Less methane was produced by these methanogens as they could not get enough food. Methane would have been useful in removing oxygen from the atmosphere but since it was in small quantity, the amount of oxygen increased leading to the event of great oxygenation that took place between the 2.2-2.3 billion years (Rawlings, par. 11).
Between the years, 2.1-26 billion years, the anaerobes mutated to form purple bacteria of aerobic nature. These bacteria could feed on molecular oxygen and carbohydrates to produce water and carbon dioxide. There also emerged a symbiosis relationship between different microbes and they achieved this through ingestion that was devoid of digestion (Rawlings, par.16). These microbes used cellular membrane to form nuclei through the process of endosymbiosis and these membranes were supposed to contain the DNA. Some bacteria which were heat and acid resistant may have come into contact with other types of bacteria to form cilia or flagella. It is possible that some of these bacteria may have merged with purple bacteria which used to breathe oxygen. This merging resulted into the formation of the mitochondria within them. Others merged with microbes that breathed in hydrogen to form other organelles. It is also possible that aerobic microbes merged with bacteria of photosynthetic nature to form chloroplasts and plastids, leading to the formation of green algae and other plant cells that are precursors of todays ones. At the end, the microbes which were formed, adapted to the new environment hence they diversified and multiplied in numbers (Rawlings, par. 17).
The photosynthetic bacteria continued to produce oxygen which was absorbed by iron found in the oceans. This led to an ancient rain that was characterized by particles which were minute and rusty. These particles are the ones which formed the ocean floors that are found today. The amount of oxygen increased leading to its conversion to tri atomic form which rose up and came to be known as the ozone layer. The aerobic bacteria continued to multiply but the anaerobic ones continued to die (Rawlings, par. 18).
Later, geologic and weather processes led to the decrease of carbon dioxide from the atmosphere. The huge number of photosynthetic microbes which produced so much oxygen, also led to the decrease of carbon dioxide and methane in the atmosphere reducing the green house effect on the earths surface cooling it completely. This continued until the levels of carbon dioxide and methane rose leading to a melt down although the microbes should have survived to form life forms which were multi cellular such as plants, fungi and animal like microbes (Rawlings, par. 19- 20).
In conclusion, it has been observed that, there could be life forms on other planets apart from the planet earth but studies are still continuing. One thing that has also emerged is that, these life forms are very different from the earth ones and this could be explained by different environments that characterize different planets.
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