We Don't Have Proof of Life on Mars

Scientific community is very slow to change its opinions, usually. Scientists sometimes are like the little chicks that will peck on chicks of another color,. And scientists do that with scientists that they disagree with. But if at some point we bring back a microbe under a microscope, it will be a sudden paradime shift and there is no life on mars. That's what Thomas coon referred to as a paradime shift.