Bad logic
Hi All
Surely it's easier to prove Mars life than disprove it, therefore the initial hypothesis should be "no known life" but not not "utterly hostile to life". WHat is unproven is life's past and/or current presence, and Mars' active hostility to ALL life. Neither has enough evidence to be given a compelling probability - methane could be geological, formaldehyde might be solar noise in the spectrum etc etc.
Adam
