Mars (NASA/JPL/USGS)

Fears that water-consuming microbes from the Red Planet would desiccate Earth are absurd.

NRPLUS MEMBER ARTICLE I n a special issue, the last of 2019, the web magazine Quillette deals with the exploration and settlement of Mars. The issue includes contributions from Michael Shermer, Cathy Young, and Michael Solana, all of whom address the question of future governance on the Red Planet. The topic might seem to some to be far-fetched, but it nevertheless provides these able conservative and libertarian writers ample scope to speculate on the always relevant subject of what might be the best principles on which to organize a government anywhere.


So far so good. However, the issue also includes an article — “One Small Step for Man . . . One Giant Leap toward the Annihilation of All Mankind,” by forensic psychologist Armondo Simon — that, written in earnest, is hands down the most absurd piece ever penned about the purported danger of back contamination from Mars.

According to Simon, humans should not go to Mars because they might return bringing microbes that would consume Earth’s ocean, leaving our home planet bereft of all water.

“So a human steps on Mars and returns to Earth carrying the water-eating bug in the folds of a spacesuit,” he writes. “The virus escapes and water begins to disappear — slowly at first and then rapidly. What can be done? Nothing. One cannot apply a vaccine to the ocean.”


The first thing to note about this doomsday scenario is that it is not original. In fact, the device of water-eating Mars bugs endangering Earth was a central element in the plot of “The Waters of Mars,” a Doctor Who episode from 2009. That, however, was comedy.


Even so, could water-consuming microbes be a possibility? By all means. In fact, we have had them on Earth for over 3 billion years. Among the first to appear were algae, which have prospered here in great numbers ever since, supplemented by wave after wave of additional types of photosynthetic organisms (a.k.a. “plants”) that use the energy of sunlight to break down water and carbon dioxide, thereby producing organic materials.

It is even possible, though by no means certain, that the first photosynthetic organisms did come from Mars, since there is natural transport of material from Mars to Earth, as meteoric impacts on the Red Planet scatter fragments that land here. In fact, we still get about 500 kilograms of Martian rocks landing on Earth every year, with a lot more imports coming in annually back in the solar system’s early days when the impact rate was far greater. Careful examination of these rocks has shown that large portions of their material were never raised above 40 degrees Centigrade during their entire career of ejection from Mars, transit through space, and reentry and landing on Earth. So any microbes contained in such rocks would have survived the trip and arrived on Earth in large numbers long ago.


It is this reality, the natural transport between planets, that underscores the irrationality of all back-contamination alarmism, regardless of whether it comes in Simon’s hysteria over the possible arrival of alien photoautotrophs or in the desire of NASA’s Planetary Protection office to take extreme cautionary measures to prevent the return of Martian pathogens. Essentially, government efforts to stop robotic or human Mars explorers from transporting dangerous microbes back from Mars fall into the same category as a campaign by the border patrol to stop tourists from bringing migratory Canada geese into the United States in their cars.


A broader point also eludes the planetary protectionists: that every biological resource on Earth (be it water, organic materials, or actual living organisms) has always been a target for exploitation by millions of species of animals, plants, and microbes already here, actively and constantly evolving and perfecting themselves for that very purpose. There might be water-consuming photosynthetic organisms on Mars, because there is some water and sunlight there. But there is a lot more of both here, and far greater opportunity to evolve life forms to maximize their exploitation. How threatening is the Jamaican bobsled team to the prospects of the northern countries in the winter Olympics? The best water-eaters in the solar system — and the most dangerous pathogens for terrestrial macroflora and macroflora — will always come from Earth.


For the rest, Simon is wrong on every point in his article. He says we should not go to Mars because there could be life there in subsurface lakes. But that is exactly why we should go: The tasks involved in drilling down to Martian groundwater, bringing up samples, and characterizing any life that might be there — to see, for example, whether it uses Earth life’s DNA/RNA system of encoding information, or an alternative — are far beyond the abilities of robotic rovers. We should instead put a base on the Moon “from which we could keep a sharp lookout for near-Earth asteroids,” he says. “Instead of inviting human extinction on other planets, let’s try to keep humanity alive on the one we’ve already got.”

In fact no lunar base is necessary to detect near-Earth objects. That is best done with orbital telescopes. But if we want to be able to do something about an incoming asteroid, we need to become a space-faring species, which will require precisely the technologies for interplanetary flight and deep-space operations needed to send humans to Mars.

It is not through fear of the unknown, but through the courage to face it, that we will find salvation.