The troof is out there!

[madriver]

"The idea that Mars was alive was a perfectly respectable position in the '30s. Even scientists who declared Mars a "dead" planet admitted that there were probably mosses and lichens to be found. Mosses and lichens! Today, we are calmly told that finding a fossil bacterium on Mars would throw us into an existential shock from which human civilisation might never recover. We have definitely lowered the bar."

http://davidszondy.com/future/otherworlds/otherplanets/mars.htm