>>11142213There’s currently no geochemical explanation for seasonal methane fluctuations that doesn’t invoke implausible scenarios outside of present observations. There’s certainly no geochemical explanation for oxygen fluctuations on this scale.
We know the Martian surface had conditions suitable to terrestrial life for a very long time. We know the subsurface could still have conditions habitable for life.
At this point, microbial life on Mars seems like the simplest explanation for observations.
Mars 2020 is going to find fossil bacterial mats and who’s the schizo then?
