There is a funny story about when Carl Sagan brought James Lovelock into the NASA exobiology think tank set up to design experiments that could determine if the

There is a funny story about when Carl Sagan brought James Lovelock into the NASA exobiology think tank set up to design experiments that could determine if there was life on Mars. Lovelock, being your archetypal scientific maverick got to thinking and with his experience with CFCs and Gaia theory he deduced that all one needed was a telltale signature: a seasonal pattern of waste compounds excreted into the atmosphere. He told Sagan, they trained the appropriate detectors and started looking. Sure enough, there were quite obvious seasonal waste deposit blooms exactly where Lovelock had anticipated. Conclusion: there IS life[-like processes] on Mars. The fact that this was not "hard" evidence drove the revelation under the rug because it does not play into the hands of the scientific community as a whole which needed experiments that required us to send probes and develop technologies to get "hard" evidence. Which I don't refute is the correct method (we would need this before a categorical "life on mars" conclusion could be given the weight of the scientific community), but I think it would be a kind of vindication of Lovelock's brilliance that HIS method is more "useful" in the real search for exobiology. Mars is in a very sweet spot that allows us to confirm our suspicions and validate our methods before we go looking and finding this "life" shit all over the place (literally). EDIT: as other comments are pointing out I think "seasonal" is misused, but I think you get my point.