The Possibility Of Life On Mars
Introduction
Other than planet earth, Mars is the only body in our solar system that is capable of accommodating life as it has the right thermal and atmospheric conditions. Controversy arises from the limited evidence of life on mars and therefore, it must be examined further to see if there are any traces of life that prove life has previously existed on Mars.
Research
In 1975 NASA launched the Viking 1 rocket into space on a 500-million-mile journey headed to the surface of Mars, and a month later its twin lander Viking 2 was launched. Almost one year later, the Viking Lander 1 completed its historical journey and reached the surface of Mars. Here, it spent 6 years collecting data and photos, all the while attempting to answer the controversial question; is there life on mars? Subsequently, Viking Lander 2 made it to Mars and began to collect evidence such as photographs and soil samples, to gain a closer look at this foreign planet. The first LR (labeled release) experiment used a robotic arm to collect Martian soil samples. Following the injection of nutrients into the soil, the radioactivity response was immediately very high. This positive response aligned with the idea that Martian soil could indeed support life.
In a subsequent experiment performed in 2013, Martian and Moon soil were collected and stored in a controlled glasshouse. Demineralized water and ambient air were used to mimic the conditions on Mars and the Moon. The experiment lasted 50 days and the results showed that the Martian soil had the highest biomass and germination percentage when compared to the Moon and Earth soil. The experiment raised this crucial question; if plants can grow in Martian soil in pots on earth, would this extend to growing plants on Mars itself in open soil? Answers to this question remain elusive require further research and experimentation. ExoMars - launched in 2016 - is a more recent and ongoing study, which consists of a joint mission with the European Space Agency (ESA) and Rosice Rosice Space Agency in a two-part mission to Mars. The first part of the project launched a satellite, used for communication and research, into orbit around Mars. Additionally, a stationary landing vehicle equipped with Trace Gas Examiners (which capture methane and other gases in the Martian atmosphere, so that they can be analyzed) was launched onto the surface of the planet. Part two of the experiment is planned to launch in 2020 to complete a scientific mission that will last for two years. The primary goal of these missions is to look for previous bio-signs of life on Mars and to investigate Martain waters, the environment, gases and their sources. Hopes run high for this mission to Mars, and the scientific community will continue to search for any signs of life on Mars in the years ahead.
Discoveries
Although the planet Mars has been deemed inhospitable to life today, research has shown that previously, conditions on mars were indeed conducive to life. At one point in time, Mars had a much warmer climate and denser atmosphere than it has now. These factors could have protected forms of life, especially microorganisms, from ultraviolet and cosmic radiation. In laboratory-based experiments, microbes were able to grow in conditions very similar to those of the lacustrine systems on ancient Mars. These specimens used a mixed metabolic approach (chemolithoautotrophic and chemoorganoheterotrophic) to survive, which emulates what might’ve been the beneficial metabolic system of organisms on ancient Mars.
In the 1990’s life-like forms were discovered embedded into the surface of a meteorite from Mars, which inspired further research into the possibility of life on Mars. Subsequently, ice, minerals and soil were uncovered leading many scientists to believe that Mars is indeed habitable. Furthermore, in 2003 researchers found slight traces of methane gas in the atmosphere, which could only be expelled by living and breathing organisms. In approximately 300 years on mars, UV radiation and oxidants destroy methane gas completely. This proves that methane is being continuously synthesized on Mars; perhaps by living organisms.
The Controversy
Many people are critical about the possibility of life on Mars, so it is important that we are open to all perspectives regarding the controversy. In the scientific and social communities, there were extensive objections to a paper published by Giordano Bruno (which outlined his exobiological theory) that suggested the possibility of life on Mars. However, these objections were more sociopolitical, rather than scientific. The reason for this could be that if Mars is found to be habitable, this would change the way that we, as humans, view the universe and life. For many, this is an incredibly complex subject that deals with the nature of life as we know it, so becomes very controversial. Although there is convincing evidence for the possibility of life on Mars, many academics have raised objections to this theory. One of the most convincing arguments for why Mars is inhabitable is the surface temperature. The average temperature on mars is about -125°c, making it unlikely to be able to support life. The differences in size between Earth and Mars, could be key in explaining why mars is unable to support life. Mars has a much smaller surface area than earth, making it unable to retain heat.
Another argument can be can established for why humans should not colonize Mars, as suggested by entrepreneurs like Elon Musk. Even if there was a practical way to survive on and colonize Mars, as some have suggested, the arrival of humans on mars would contaminate the planet with human bacteria and fungus, which could be detrimental to the natural environment on Mars. Looking at this through an ethical perspective, we can’t colonize mars without violating the Principle of Scientific Conservation. If we invade Mars with an array of human life, this could potentially be destructive to the possibility of Martian life; and many of our questions concerning the matter may be left unanswered.
