Evidence of Prehistoric Bacterial Life found from Mars: I wonder if there are still any possible life-forms on Mars

From the beginning of time, the universe has always been a mystery to mankind. We have been intrigued by the many wonders of the universe and as time elapsed, technology increased, and the minds of human beings have evolved, extraterrestrial life remains a recurring interest. The rising curiosity of extraterrestrial life has plagued the minds of Scientists to common folk. People have held various theories based on their imagination on what life would resemble.
Over time, many great discoveries have been made as well as many excursions into outer space. Planets, stars, galaxies, comets, our moon and sun we’ve discovered. We have advanced enormously within the technology field and this advancement has enabled man to be educated about space and the wonders thereof. However, the greatest question of extraterrestrial life has not been answered. Many of us perceive life forms to be humanlike species or “Cycloptic” (one-eyed) creatures similar to the aliens depicted in Science fiction films. However we fail to realize the life can be as small as bacteria or as enormous as prehistoric creatures like dinosaurs.
The planet Mars, is one which is very close to the characteristics of our very own earth and with recent missions to Mars in the search for life I believe that life does exist on Mars upon recent findings and also theories which dictate the requirements for life, the “Habitable Zone”.
A NASA research team of scientists discovered evidence of what is believed to be primitive bacterial life on mars. The findings were from 1 of 12 meteorites found on earth believed to be from the planet Mars. Several mineral features and signs of biological activity as well as possible microscopic fossils were present. The meteorite “ALH84001” is said to be approximately 4.5 billion years old. The other 11 meteorites date back to 1.3 billion years. The proposed primitive life forms were discovered within mineralized fractures in the meteorite and were all in close proximity to each other. Hydrocarbons also known as breakdown products of dead micro-organisms here on earth, were also found as well as mineral phases consistent with by products of the meteorite. (Williams,2005)
A two-year investigation was underway and co-led by JSC planetary scientists Dr. David McKay, Dr. Everett Gibson and Kathie Thomas-Keprta of Lockheed-Martin, with the major collaboration of a Stanford team headed by Professor of Chemistry Dr. Richard Zare, as well as six other NASA and university research partners.(NASA,1996)
Dr. McKay explains that it was not a single discovery which led the researchers to believe it was evidence of life on mars but a combination of all the findings.
"There is not any one finding that leads us to believe that this is evidence of past life on Mars. Rather, it is a combination of many things that we have found," McKay said. "They include Stanford's detection of an apparently unique pattern of organic molecules, carbon compounds that are the basis of life. We also found several unusual mineral phases that are known products of primitive microscopic organisms on Earth. Structures that could be microscopic fossils seem to support all of this. The relationship of all of these things in terms of location - within a few hundred thousandths of an inch of one another - is the most compelling evidence."(McKay,1996, para. 4)
In recent times, the launch of the Mars rovers; Opportunity and Spirit were responsible for the investigation of water on the planet mars as well as the geological history of Mars and whether it shows signs of water being present at one time. Spirit was launched on June 10th 2003 and Opportunity departed for Mars on July 7th 2003. They Landed on Mars about 7 months later. Spirit landed at Gusev Crater on January 3rd 2004 and Opportunity Landed on Meridiani Plaunum on January 24th 2004. The rovers completed their first missions within 90 days of being on Mars’ surface and are still there today after undergoing many extended missions. Today the Rovers are still gathering data of Mars’ geological formations for scientists here on Earth. The Rovers have taken more than 260,000 photos and sent them back to Earth.
Due to budgetary constraints along with technological resources it is not yet possible to land humans on the surface of mars. Mars’ atmosphere makes it unlike any place on earth. The atmospheric pressure is less than 1 percent less than that on the surface of Earth thus making the air too thin to facilitate survival without a spacesuit. The air contains only trace amounts of oxygen which means that Mars lacks an ozone layer. Therefore human life can be ruled out.
The lack of liquid water on the surface of Mars has not hindered the search for life. Evidence suggesting that pockets of liquid water could still exist underground, kept warm by remaining volcanic heat. In that case, Mars may currently have underground zones of habitability. (Bennett & Shostak, 2007, pg. 279)
The launch of a new rover “Curiosity” is expected to land on August 6th 2012. Its main goal is to determine if Mars has or ever had the environments to support life. The rover is able to drill and dig and is equipped with 10 science instruments which include chemistry labs to test these rocks and identify the elements within them. Previous probes tested for surface water but Curiosity’s focus is to search for other ingredients which facilitate life for example organic carbon, which is vital for life here on earth. Carbon, oxygen, hydrogen and nitrogen make up 96 percent of the mass of a living organism. Ammonia, Methane and Ethane are liquids which also can possibly support life although not yet proven. Radiation also plays a role in determining life’s existence. Organic molecules are said to be destroyed by solar radiation since they are not protected by their atmosphere on the surface.

For life to exist on earth, there are certain environmental requirements which need to be present. Although many species exist in different environments, there are things which must be present such as water, sunlight, and air which living organisms on earth use in order to maintain their survival. If in our search for life on mars, we come across not one but a combination of those basic requirements, there could be grounds to assume that there may be life present. Although life on earth exists within particular temperature ranges, and mars is known to be much colder than earth. We have found micro- organisms living in the harshest conditions near the earth’s core as well as in the coldest regions. Who knows, life on mars could have evolved to adapt to the harsh temperatures present there. With the use of the pictures from the rovers which are deployed to Mars’ surface, we could see physical evidence of probably water or ice if it exists. Life on earth is known to be “carbon based” as carbon is one of the main ingredients in harbouring life, with the assumption that life outside earth will need the same basic requirements, we can presume that life on mars would be “ carbon based”. Humans and some animals need oxygen in order for respiration to take place; other organisms such as plants use it for respiration. Nitrogen and Oxygen are the other 2 main components in air that play a major role in the sustenance of life. With the rovers and other equipment used, we may be able to physically see signs of water, or even a cloud of nitrogen gas. If there is some sort of mechanism present to test the air within Mars’ atmosphere and specimens taken from rocks and other objects found on Mars’ surface then we could combine the data and according to the trends, determine whether it is consistent enough to assume the existence of life. Also by observing rock patterns and radioactive dating we could determine whether water ever existed on Mars, whether in the past or at present.
Though we have come a long way and advanced dramatically with our technologies, the question of life outside earth is still unanswered. As the rover “Curiosity” embarks on a possible life changing voyage we can only hope for some answers. The planet Mars holds many mysteries and therefore the quest for life may not be the only question answered.

References

1.Bennet, J. & Shostak, S. (2007). Life in the Universe (3rd edition). San Francisco, CA
2. Evidence of Ancient Martian Life in Meteorite. Retrieved from :http://nssdc.gsfc.nasa.gov/planetary/marslife.html
3. NASA press release on the discovery retrieved from: http://nssdc.gsfc.nasa.gov/planetary/text/mars_life.txt
4. NASA rover launched to seek out life clues on Mars. Retrieved from: http://www.reuters.com/article/2011/11/26/us-space-mars-idUSTRE7AN0AT20111126