When Curiosity shakes off all the dust from landing and completes all its system checks, it will begin its one-year trek (by the Martian calendar) up Mount Sharp, with one of its aims to discover if Mars was ever habitable for primitive life.
What if it was? Wow! Great, what a find!
What if the life is still there? That would be absolutely … um, problematic.
Do we abandon our hopes for settling Mars and eventually terraforming it if we find the Martians are still around, even if they’re only microbes? We have to admit, that’s not in our nature. The history of humans has been to expand ever outward, invade new lands, and if we find people already living there, decimate the native population.
It was only in the 20th century that we began questioning the deeds we’ve done in the name of manifest destiny, even if the questions didn’t stop those deeds from being inflicted on the invaded with increasingly brutal efficiency. I hope we can do better in the 21st century. But will we do better when we leave this planet?
If we find life exists on Mars, it would be a momentous discovery, the first proof that life exists beyond our home world. Could we then simply wipe it out by transforming the planet to make it suitable for us? Could we resist?
It would be easier to resist if the Martians walked and talked, even if indigenous populations haven’t stopped us before. But microbes? Would we let microbes stand in the way of our destiny to colonize new worlds? Microbes can’t even stand!
There are scientists who argue that we should leave Mars alone if we do find primitive life exists there. There are many others blithely drawing up plans and schemes to terraform Mars as quickly as possible, even if quickly means centuries.
Of course, if the Martians are there, they may have something to say about it. The surface appears poisonous to any life, so any living Martian microbes must be deeper down. We may find the microbes below the surface can coexist with a terrestrial ecosystem above them. We might even make the claim the coexistence can work, and apologize later when it doesn’t – albeit an apology to no one in particular.
The Martian microbes may be so alien to us that they can’t interact with our life forms, letting us live side-by-side without taking any day-to-sol notice of each other. Or there’s a chance the Martians may be related, that life here began out there. It was only when an asteroid blasted into Mars, sending bits of the planet into space, that microbes hitched a ride to Earth billions of years ago.. And if we are related and we can interact, we may sell the Martians short only in our peril. Martian microbes may welcome invaders too warmly, taking their time to infect and decimate the colonists before catching another ride back to Earth.
I hope Mars is dead. Life would be so much simpler that way.