Well, we do have evidence of past life on Mars - just not conclusive evidence. See https://en.wikipedia.org/wiki/Allan_Hills_84001 https://en.wikipedia.org/wi

Well, we do have evidence of past life on Mars - just not conclusive evidence. See https://en.wikipedia.org/wiki/Allan_Hills_84001 https://en.wikipedia.org/wiki/Allan_Hills_84001 and https://en.wikipedia.org/wiki/Microbially_induced_sedimentary_structure https://en.wikipedia.org/wiki/Microbially_induced_sedimentar... And, of course, that's not evidence that there's still life on Mars.