Begs the question...how long do we spend trying to find evidence of life on Mars before we just plant some there?
I’ll bet if they just planted a single Kudzu vine with the next probe, in 10 years it would be a green planet. (Kudzu jokes to follow...)
Or following that same line of reasoning, they say that ants, cock roaches, and certain insects will out live the nuclear war. Why not deliver a nest of those? It doesn’t sound like what you would like to populate a planet with, but over time, they might accumulate the organic decay matter that makes it possible for other life to take hold...
Paging Lewis Grizzard, paging Lewis Grizzard.
"KUDZU: Nothing grows faster than a kudzu vine. It has been known to cover entire homes in Georgia where the families are asleep for the night. They are then trapped inside and can’t get to a convenience store, so they starve. Those who try to eat their way out of kudzu quickly have their innards entangled in the vine because no matter how much you chew it, the blamed stuff just keeps on growing."