“There is a ticking clock now,” Princeton astrobiologist Chris Chyba said at last week’s Breakthrough Discuss conference, conducted at Stanford University. The race isn’t to find life on Mars — it’s to find it in time before we contaminate the Red Planet with our Earthly microbial fauna.

We don’t know if there is life on Mars or not. The Red Planet seems like a good candidate, and we’ve found significant evidence that it might have held vast quantities of liquid water on its surface at once point in its geological past — a prerequisite for life as we know it. There’s also a good case to be made against this, with its lack of active tectonics and atmosphere. If Martian life exists, it’s bound to live beneath the surface where it’s shielded from the devastating radiation, and almost certainly microbial. Either way, it’s an exciting area of active research, but we might be on a clock.

With every mission we send to Mars, every lander, and especially with the planned manned missions to Mars, we risk contamination with microbial creatures from Earth. These alien microorganisms (technically, they’re Earth microorganisms, but to Mars, they’d be aliens) could overpower and destroy potentially existing native fauna.

For instance, Elon Musk’s highly anticipated mission to Mars aims to bring people to Mars within the decade, and Boeing CEO Dennis Muilenburg has announced similar plans. For the Martian life, the effects would be unforeseeable — hence Chyba’s remarks. But people weren’t necessarily fond of his idea. Longtime space entrepreneur Jeff Greason, who serves as chairman of the board for the Tau Zero Foundation, poked fun at Chyba:

“If all you want to do with the solar system is look at it, the rest of us would like to borrow it for a while. … There are things to do with these bodies other than science.”

Others have claimed that there’s no reason to believe Earth’s microbes would take over the Martian natives.

“You could terraform Mars, and the microbes on Mars would survive,” said Robert Zubrin, founder and president of the nonprofit Mars Society.

But Chyba makes a very valid point. If we don’t really know what could happen, isn’t it better to take extra precautions? He advocates a precautionary approach, what he calls the Smokey the Bear argument: “Until we know more, let’s be careful.”

To me, this sounds like a sound idea. There are many unknowns when it comes to Mars and its habitability, but we can take measures to limit the potential damage, for instance by ensuring that no microorganisms escape through astronauts’ space suits. If we send people to Mars, microbes are bound to come along for the ride, and the effects can truly be unforeseeable. We shouldn’t just concede that we’re gonna contaminate Mars no matter what.

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