The NASA robot Curiosity discovered evidence of methane seasonal variation.
Source: Science News
NASA’s Curiosity rover has found evidence that methane in Mars’ thin atmosphere varies during the year. Higher concentrations appear in late summer and early autumn in the northern hemisphere and lower concentrations in the winter and spring, researchers report in the June 8 Science.
What’s more, Curiosity also spotted organic molecules previously unseen on Mars preserved in mudstone, some of the same researchers report in another study in the same issue of Science. Although neither methane nor organics alone are signs of life, the implications for astrobiology are “potentially huge”.
That finding was exciting, because methane doesn’t last long in the Martian atmosphere before ultraviolet radiation from the sun destroys it. Something must have been creating or releasing the gas as astronomers watched. On Earth, most methane is produced by living creatures, so the plumes raised hopes that Mars supports life.
This is the graphic of methane quantity in parts per billion.
Methane can be abiotically produced by hydrothermal sources, which emit carbon dioxide, causing the following chemical reaction.
Or by basalthic erosion, but the fact there is a season variation, can be interesting.