Potential Life-Harboring Worlds in Our Solar System
Studies of the universe has elicited a lot of interest in regards to the existence of life in other planets and moons. So far, planet earth which revolves around our solar system is the only planet known to favor life. As expected, the curios nature of human beings has pushed them into conducting research on regions outside the solar system to locate any trace of life on other terrestrial bodies. Little has been achieved in proving that there are other body masses in the universe apart from earth which support life. Determining existence of life on other bodies in the universe has thus been turned into probability considerations. Existence of different kinds of factors and environments that support life has led to certain body masses being speculated as being capable to support various forms of life. The paper discusses the different planets and moons speculated to support life, scientific evidence behind the speculations, the conditions and strength of the claims.
Planet Mars is often considered as the best candidate to demonstrate that life actually exists beyond earth. Its proximity to earth has raised a lot of concerns regarding the planet having similar conditions to our planet thus the possibility of harboring life. It is the vast interest that astronomers have had on the planet that led to a series of research to establish its suitability to sustain life. For instance, the year 1976 saw NASA take the big step to send the Labeled Release (LR) experiment to detect the presence of life in the planet. Key scientific discoveries regarding the planet’s suitability to sustain life were realized in the year 2000. NASA through its Mars Global Surveyors was able to take images of the planet. The images revealed that the planet had several large gullies thereby suggesting that water used to flow through the gullies (Christensen, 2003). Don't use plagiarised sources.Get your custom essay just from $11/page
Evidence of water is quite critical in determining the probability of a place to harbor life. Water is considered one of the elements which support life and therefore its presence in Mars indicated that the planet was once capable of supporting life. Several tiny bodies which fall from Mars to earth have also suggested the possibility of life on the planet. For instance, scientific discoveries of the Mar’s meteorites which had fallen in Antarctica established that they resembled fossils. The fossil remains were alluded as being of different forms of bacteria. Evidence of fossils from the stones therefore, pointed out that there was once some form of life in the planet. Recent research on mars have revolved around finding the suitability of the planet to support life instead of focusing on earlier investigations which aimed to prove that life actually existed. Some of the pieces of evidence as demonstrated by presence of hot springs beneath the rocks and instances of precipitation provide a solid argument that the planet can indeed support life.
The idea that life exists on Mars however remains to be an argument whose strength has been questioned. Even though astronomers agree that the planet might have supported life in the past due to the presence of water, its current state as far as facilitating life is questionable considering the fact that the planet is very dry. Also, the claim on fossil presence being an indication of past life on the planet have been refuted as the meteorite structures perceived by to be that of fossils were found to result from chemical reactions and not biological processes.
The scientific discovery of liquid water in Europa, Jupiter’s moon provided indications of the planet supporting life. Scientists discovered that the planet had a lot of buried water beneath its exterior surface. The icy nature of the moon’s surface had made scientists disregard it as a habitable location due to lack of oxygen. However, it was discovered that the buried liquid water beneath it provided much oxygen necessary for survival. The water molecules are broken down by Jupiter’s radiation into hydrogen and oxygen molecules.
The scientific discoveries on Europa allowed astronomers to establish the presence of three critical conditions required to support life. Like in Mars, Europa has a lot of water. Availability of water on the moon was confirmed by the Galileo spacecraft which orbited Jupiter from 1995 to 2003. Images from the spacecraft revealed the presence of a large sea water beneath the planet’s earth. Furthermore, it was established that the amount of ocean water in Europa is much greater than the earth’s. The ocean’s bottom was revealed to be a salty sea floor.
The presence of chemical reactions in Europa is considered another key role that reveals the possibility of life on the moon. For life to exist, several chemical reactions need to occur with the support of key elements such as hydrogen, oxygen, sulfur and many more. Scientists believe that these elements were present in Europa when it was formed. Likewise, scientists believe that bombardment of the body mass by asteroids and comets added more organic elements to its surface hence providing a favorable ground for increased chemical reactions. Energy is another critical necessity for life. Even though the icy state of Europa is regarded as barring the sun’s rays from reaching its surface, it receives a lot of radiation from Jupiter. Radiation is not viewed as the ideal source of energy for life. However, scientists claim that Jupiter’s radiation might not be that destructive as it has to travel long distances before reaching the bottom surface of the moon. There, the radiations provide the necessary energy needed to facilitate chemical reactions hence sustaining life.
Weaknesses in Europa supporting life is however seen in lack of adequate evidence supporting other critical elements required for life. Apart from the availability of salty water and enough oxygen to sustain life, the presence of chemical reactions and adequate energy is still refuted. On earth, photosynthesis is viewed as an ideal way through which energy is generated with the sun’s help. However, the process is not possible in Europa as biodiversity’s can only be found at the bottom of the thick ocean making it hard for the sun rays to penetrate.
Another place outside the world which has led to speculations of life is Titan, one of the moons which orbit Saturn. In fact, Titan is regarded as the closest place besides earth which might support life. Scientific discoveries about the possibility of Titan to support life were revealed after emergence of images from the Cassini mission conducted by NASA and ESA. The images presented Titan as showing signs of molecules which can only be found on earth.
One great evidence to support claims of Titan hosting life is the presence of chemical elements found in various forms of life. Carbon and Amino Acids are some of the great elements common among all forms of life. Lack of proof of the existence of these elements in other terrestrial bodies has therefore contributed to the doubts raised against the existence of life on such locations. However, it has been established that these elements are being made on Titan. The presence of basic elements of life such as carbon and proteins on Titan, therefore, mean that the moon might be harboring different forms of life (Sotin & Tobie, 2008). Availability of chemical substances such as hydrogen, methane and nitrogen provides the probability of chemical reactions occurring. The reactions are driven by the energy provided from sunlight in Saturn’s magnetosphere. Apart from the key elements depicted in various forms of life and the necessary energy, Titan is also depicted to have the necessary water and oxygen required to sustain life. Enceladus, another moon that orbits Saturn produces water plumes which then rain down Titan’s upper atmosphere. It is the water that provides the necessary oxygen needed for survival.
The argument on Titan being one of the places outside earth to harbor life is indeed strong. It points out to the existence of almost every critical element needed to sustain life. They range from the presence of chemical elements which comprise living organisms such as carbon and amino acids, ideal substances needed for chemical reactions and oxygen. However, the major argument against Titan offering habitable grounds is seen in the excessive presence of liquid methane and ethane. The two elements provide quite cold conditions which prove it hard for the organisms to survive.
In conclusion, it has been established that several arguments have arose regarding the possibilities of other terrestrial bodies apart from earth harboring different forms of life. Interest in ascertaining the truth on whether life actually exists on other locations outside the world has been enhanced by the numerous expeditions taken by astronomers to study the structure and composition of terrestrial bodies. The scientific discoveries have established that Europa, Titan and Mars are the terrestrial bodies likely to showcase instances of life existence. These terrestrial bodies are said to harbor characteristics such as presence of oxygen, water, carbon, amino, energy and appropriate grounds for chemical reactions. Despite proof of the above factors, the habitability of such areas by various forms of life remain to be mere speculations as no proof of life has been established. Likewise, the several contradicting opinions brought forward against the existence of evidence on life outside planet earth elicits a debate which can only be decided with the emergence of proof.
References
Christensen, P. R. (2003). Formation of recent Martian gullies through melting of extensive water-rich snow deposits. Nature, 422(6927), 45-48.
NASA. Europa could have the essential ingredients needed for life: https://europa.nasa.gov/europa/life-ingredients/ Accessed 4th February 2020
Shwartz Mark.New findings support prospect of life on Jupiter’s moon Europahttps://news.stanford.edu/pr/00/000126Europa.html Accessed 4th February 2020
Sotin, C., & Tobie, G. (2008). Titan’s hidden ocean. Science, 319(5870), 1629-1630.