What If We Go to Mars and Find Out It Is Already Inhabited?

October 17, 2017 – Elon Musk wants humanity to establish itself on a second planet and he has focused on Mars as the most likely candidate. But what Musk doesn’t talk about is the potential to find some form of Martian life. We haven’t found it yet, but then we really haven’t specifically looked for it with the landers and rovers that started studying Mars just 41 years ago.

Only the Viking landers were equipped with experiments designed to sniff out potential evidence of life signatures in samples dug from the Martian regolith. The results of the tests, when aired in the press in 1976 stated that life had not been discovered. But in April of 2012, a revisit of the data collected from Viking’s two landers and their Label Release Experiment measuring the gases emitted by soil samples heated to 160 Celsius (320 Fahrenheit) degrees, overturned that assessment.

The results, published in the International Journal of Aeronautical and Space Sciences (IASS) stated there was 99% certainty that microbial life exists on Mars. Unequivocally the results the investigators reported were not caused by any Earth-borne contaminants arriving on the landers but were unique to Mars. The results were also consistent with similar tests run on Earth in Antarctica with conditions resembling the extremes of cold and dryness found on the Red Planet. Since Viking, NASA has sent many landers and probes to Mars including Opportunity and Curiosity (the latest), but strangely the agency has never tried a Viking retest or included more advanced life detection experiments, a surprising oversight by the agency. Instead, we have looked for organic molecules, the presence of water today, and evidence of significant surface water in the Marian past. And we have found all three.

The Mars 2020 lander, which will be the successor to Curiosity, doesn’t include any onboard life detection experiments in its current configuration. One wonders why not? Is NASA deliberately avoiding the question of life on Mars? And if so, why?

There could be several reasons.

One is religious. If life is not unique to Earth then the creation myths of the world’s major faiths are called into question.

The second is the ethical dilemma that Mars presents. An inhabited Mars, even if only microorganisms, is not something to be trampled upon and suborned by alien life brought to the planet by humanity. That would be a criminal act.

The third reason is the profound implications of finding Martian life in a world seemingly inhospitable to it, and what that could mean for other places in the Solar System and beyond where conditions seem equally if not more inhospitable.

Here are just a few relatively nearby examples:

  • Europa, one of Jupiter’s moons, has a subsurface saltwater ocean larger than all of the oceans on Earth. What kind of life can be lurking there?
  • Ceres, today designated a dwarf planet, the largest object in the Asteroid Belt, has also detectable subsurface water. The same question can be asked.
  • Enceladus, where Cassini flew through saltwater plumes at the south pole and detected organic molecules is another life candidate. Once again, the same question.
  • And then there is Titan, Saturn’s largest moon, where life may not be based on water but on other liquids.

Planetary scientists today note that Titan bears similarities to Earth with liquid both on the surface and in its thick atmosphere, that falls as rain and flows through river valleys into lakes and seas. But there are differences as well. It’s not water but liquid methane in those rivers and seas. And the temperatures on Titan are so cold that water exists as ice and forms much of the land mass through which those methane rivers flow.

On Titan there is also an abundance of organic molecules bearing a resemblance to the building blocks of life we find here on Earth. And needless to say life on Titan may be organic-based but one cannot imagine it turning into anything resembling that which exists on Earth. Would a future robotic rover or human visitor even recognize life on Titan if stumbled upon?

Considering the Viking experiments and the controversy associated with detecting or not detecting life on Mars, it is pretty clear that recognizing life we find elsewhere in the near-space of the Solar System will be difficult. And when we can’t devise an experiment to recognize it or visually identify it, yet it’s there, that will certainly be problematic.

That to me makes Elon Musk’s Martian venture and the Mars One project very dangerous steps for our species to take. Establishing colonies there means permanent contamination of an alien ecosystem with the potential extermination of its native life. Or maybe that life kills us before we kill it.

In H.G. Wells, War of the Worlds, the Martians, with their superior technology, arrive on Earth and overwhelm our human defenses. Ultimately, however, it is our native microbial allies that kill them off.

Wells parable should not be taken lightly. We may not come as invaders to conquer Mars, but when we arrive there we may face the risk of being exposed to an incompatible form of life that kills us.

Yet it is clear that we, as a species, are outward bound to go beyond Earth this century. Why does that mean we need to find alien ground to colonize?

We have the potential to engineer communities in space, to make them self-sustaining habitats capable of duplicating conditions on Earth. A Deep Space habitat would use resources mined from lifeless asteroids and comets to provide the material, fuel, water and breathable air needed to be self-sustaining. Such habitats could draw upon the continuous energy of the Sun and move around on the solar wind. Habitats could even simulate Earth gravity, and if and when we want to feel like we are on the Moon, Mars, or elsewhere, we could create habitats that simulate those bodies’ conditions.

To me, this is a far better way for us to establish our off-world presence than what Musk and others are proposing, and certainly, one that is less fraught with risk to both our species and to life that may already exist on nearby alien worlds.


This image is of participants in The Mars Desert Research Station (MDRS), owned and operated by the Mars Society. If astronaut explorers like these arrive on Mars and inadvertently contaminate the planet with Earth microbes they may snuff out existing Martian life. Colonization would do even more significant damage.

Len Rosen lives in Toronto, Ontario, Canada. He is a researcher and writer who has a fascination with science and technology. He is married with a daughter who works in radio, and a miniature red poodle who is his daily companion on walks of discovery.