Evidence for life on Mars has been mounting ever since astronomers started studying the planet, but actual proof of living organic life on Mars itself has yet to be found. What is clear from the discoveries on Mars is that the planet contains some interesting clues, history and composition that warrants further investigation. Of the findings, new and old evidence of the possibility of life on Mars indicates the presence of water, minerals, riverbeds and fossilized asteroids. A brief chronology of the findings about Mars illustrates some of what evidence of life on Mars, and lack thereof, there actually is.
2000- 2010: Infrared spectroscopy reveals water
In 2010, the Geochemical Society claimed more than just sulfates have been discovered on Mars, but several other minerals that the society says ‘reads like a mineralogy textbook’. Evidence of these minerals reveal themselves through infrared spectroscopy and add to the reasoning that there may have been historical bodies of water on Mars. More so, the data may provide partial corroboration that life could have once existed on Mars. However, the same evidence is not solely evidence of life, and therefore not absolute proof that life did exist on Mars.
2009: Methane gas discovered on Mars
Methane gas, according to NASA is evidence of a ‘living planet’, and possibly life. This is because both deep within the Earth’s crust, and long ago in Earth’s history a biological parallel exists in which microorganisms produce methane using carbon dioxide and hydrogen, both believed to be present on Mars.
2008: Frozen water confirmed on Mars.
After the Mars Phoenix lander arrived at the North Pole of Mars it performed tests that confirmed the existence of frozen water on Mars. Specifically, vaporization of what was believed to be ice on Mars, validated the substances ability to do just that, an attribute shared by frozen water. NASA added to this confirmation when in September of 2009, it announced photographs taken by the Mars Reconnaissance Orbiter revealed subterranean ice just below the surface of Mars after meteorites had struck the area of the photograph.
2004: Evidence of Martian Sulfates discovered
The presence of sulfates and salt deposits on Mars means that it is quite possible the planet held water according to Dave Morrison, on NASA.com. Moreover, a chemical signature of these substances was found by the Mars rover ‘Opportunity’ in 2004 providing further data for the verification of life and/or water on life past or present. However, to conclude life existed on Mars simply due to the presence of water is a false conclusion, as life cannot necessarily be sustained by water alone.
2004: Hematite found in ‘blueberries’
In 2004, after the landings of the Mars rovers Spirit and Opportunity, the presence of ‘blueberries’ were found. These objects aren’t actually blueberries, but a composite material containing hematite that is thought to have been formed during a time when water was present on Mars. These blueberries are more evidential of possible water in the history of Mars, than of the present.
1996: The ALH 84001 Rock
A 1996 discovery relating to a fossilized rock from Mars that was found in 1984 and named ALH 84001 was believed to hold evidence of past life on Mars. According to the Students for the Exploration and Development of Space, the rock, originally from Mars, landed on Earth 13,000 years ago. This Martian rock, that catapulted into Earth after being flung out to space by an asteroid that hit Mars, contains what scientists believe to be fossilized micro-organisms.
Evidence to the contrary:
The findings on Mars isn’t all verification of possible building blocks of life on Mars such as water. Older tests from the Viking Landers do provide nullification to the idea life does presently exist on Mars according to space.com. Moreover, the Viking landers performed tests that would detect organic molecules in soil from the surface of Mars, but came up with no verification.
Additional disqualifiers of new evidence of life on Mars is the simple fact no life has been found yet despite numerous tests from the rovers Spirit and Opportunity. These rovers have been instrumental in discovering what could be possible, and what could have been possible, but have not provided new evidence that life does indeed exist on Mars. So as of yet, the new evidence for life on Mars is that there is no conclusive evidence for such life, but rather indicators that life could exist in some parts of the planet’s interior and possibly have existed in the past.
Sources:
(1) http://seds.org/~spider/spider/Mars/mmetlife.html
(2) http://nasa.gov/
(3) http://www.space.com/scienceastronomy/061024_mars_viking.html
(4) http://phoenix.lpl.arizona.edu/06_20_pr.php
(5)http://www.geochemsoc.org/publications/geochemicalnews/gn142jan10/diverseaqueousenvironments.htm
