So is there life on Mars or is the red planet a barren wasteland that is a sure doom for all forms of life? Well, while the Mars Rover hasn’t stumbled across any tiny green men or located water, scientists are entirely ruling out the possibility of a life cycle on Mars.
This is because the presence of methane gas, the essential building blocks of life have been found on the planet at various levels. Here’s a bit of a recap on the different Mars methane discoveries and what scientists believe is the reason behind the gas’ existence on the planet.
Methane was detected on Mars in 2003, but then found to be absent in 2005, reinforcing the idea that some sort of lifecycle existed on the planet that was using up this methane. Mission project scientist John P. Grotzinger believs that the methane could be a waste product of certain microbes. There’s also the possibility of serpentinizaion. This is when a rock emits both gases and water as result to natural changes. If the methane is being produced from these changes, it gives reason to search for the possibility of life in these hydrothermal areas.
Okay, now cut to 2013, scientists declared that any possibility of life on Mars was unlikely. Then, in November of that year, methane levels spiked and remained high until January before tapering off and rising again in June. Scientists weren’t able to identify the direct source of the gas, but suspected that an underground source had been disturbed.
“These are molecular cages of water-ice in which methane gas is trapped. From time to time, these could be destabilised, perhaps by some mechanical or thermal stress, and the methane gas would be released to find its way up through cracks or fissures in the rock to enter the atmosphere,” University of Michigan professor, Sushil Atreya told BBC News.
The key seems to be determining if the methane has a biological or geological origin. Life on Earth favors a lighter version of the element (carbon-12), over a heavier one (carbon-13). Life can exist only if it has the capacity to trade in carbon molecules and scientists would need to find isotopes of carbon atoms in the gas similar to those found on Earth to determine if life had a genuine shot on the planet.
So until we the Rover stumbles upon a flying saucer with tiny green men, this seems to be our best shot at answering the question: can Mars support life?