A recent paper published in the journal Science presents the failed attempts for NASA’s Curiosity rover to detect any significant amounts of methane on Mars. This information is deemed to reduce our chances of finding life on the planet since scientists use methane as an indicator of life.
Methane = Life
The reason for methane being an indicator of life is the connection and strong correlation between life and methane on Earth. Since 90 percent of all Methane in Earth’s atmosphere originates from living organisms.
Scientists thought that there was much more methane on Mars since previous evidence indicated so. But with Curiosity’s much more sensitive instruments, the observations that have now been done provides strong evidence to the contrary.
It should be noted however that Curiosity has found methane but in small amounts. The concentrations also vary with location, time of the day and the season of the year.
This methane could have been created geologically, as when hot water reacts with hydrogen gas and carbon dioxide. But the fact that it could have been created geologically, does not rule out the possibility of it originating from methane-producing lifeforms.
But Life Should not Be Ruled Out
Robert Zubrin is the co-founder and president of the Mars Society, he elaborates on the missing methane in an interview with CNET last week. He said that microbial life may still exist on Mars. And that the low amounts of methane that has been found on the surface do not exclude the existence of life below the surface.
Since much evidence indicates a once warm and wet period on Mars several billion years ago and that something happened to transform the planet to cool down to a dry desert.
The Mars of today lacks a considerable atmosphere and only have sporadic magnetic shielding. This transformation could imply that if life previously existed during this much more life-friendly period, it could have retreated below the surface.
There is still possibly water stored deep below the surface, and if life would exist here, it would also be safe from the dangerous radiation on the surface, with Mars lacking a protective atmosphere.
This data does reduce the chances of finding life on Mars. But a low chance is still a chance. And the question of life on Mars remains unanswered.
Low Upper Limit to Methane Abundance on Mars