To date, existence of life on other planets other than the Earth has elicited a lot of discussion. There have been investigations of several planets in search of favorable conditions for human survival. Major basic factors have been considered, especially those that make the Earth habitable. These concurrents include the presence of oxygen, favorable temperatures, availability of water, and protection from life-hazardous radiations, as well as favorable atmospheric pressure and gravity. The length of days is also an important factor. Mars appeared to be more supportive to organic and human life of the planets studied so far (Wiley, 2008, p. 340).
Various similarities exist between the Earth and Mars. A day in Mars lasts 24 hours, 39 minutes and 35.244 seconds whereas on Earth it is 24 hours, which is a very slight difference. The area of dry land on our planet is 29.2% of the Earth surface while Mars covers a total of 28.4% of the surface area. The axial tilt of the Earth is 23.44%u25CF while that of Mars is 25.19%u25CF, which makes the seasons similar. Just like the Earth, Mars has an atmosphere that filters cosmic radiations from the surface. Observations made by NASA in their space exploration have confirmed the existence of ice water on Mars. The elements that support life have also been found in sufficient quantities (Weissman, Johnson, & Mc Fadden, 2007, p. 65).
Various differences exist between the Earth and Mars. There are no water bodies in comparison to the Earth. The temperatures on Mars vary between -63%u25CFc and -140%u25CFc. On Earth, the lowest ever recorded temperature in the Antarctica was -89.2%u25CFc. Gravity on the Mars surface is 38% of that on Earth. Atmospheric pressure is approximately 6 millibars while that on Earth is 1013.25 millibars. Carbon dioxide forms the main component of the Martian atmosphere with a partial pressure that is 15 times higher than on mother Earth. In addition to this, levels of carbon monoxide exist in significant levels on Mars while these levels are insignificant for earthly inhabitants (Hewitt & Jackson, 2009, p. 76).
The similarities between our native planet and Mars give some hope that if something inevitable happens to our mother Earth, we will successfully settle on Mars. The similarity in the length of days makes Mars similar to Earth. There is also the advantage of connatural seasons despite the fact that they last twice longer than on Earth. Furthermore, Martian atmosphere gives some protection from cosmic radiation. Presence of ice at least gives hope for terraforming Mars to acquire water. The fact that all the necessary elements in order to support life are available on Mars is also an encouragement for humans in the hope for settlement on this planet in case of emergency (Weissman, Johnson, & Mc Fadden, 2007, p. 200).
However, various factors tend to diminish the hopes for human settlement on Mars. The low gravity may bring weightlessness and its related health effects. Human life will then require finding means of adjusting to the very low temperatures, which occur on Mars. The lack of standing water bodies would also pose a great challenge to life as water is essential for existence of people. The pressure below, which people cannot survive without, foresees the use of pressure suits set at the Armstrong limit of 61.8. That means that the very low atmospheric pressure on Mars would present a challenge to life. Abundant levels of carbon monoxide and carbon dioxide are also poisonous to life (Hewitt & Jackson, 2009, p. 321).
Terraformation of Mars is possible. This would allow humans to survive on Mars unaided. In April 2012, German Aerospace Center confirmed the remarkable capacity for adaptation of lichen and cyanobacteria photosynthesis in simulated Martian conditions. This shows the feasibility of viewing Mars as our next home after the Earth (Weissman, Johnson, & Mc Fadden, 2007, p. 57).