Colonizing Mars may require humanity to tweak its DNA

Artist's impression of a city on Mars, which SpaceX wants to help establish with its Starship transportation system.
Artist's impression of a city on Mars, which SpaceX wants to help establish with its Starship transportation system. (Image credit: SpaceX)

If humanity is ever going to settle down on Mars, we may need to become a little less human.

Crewed missions to Mars, which NASA wants to start flying in the 2030s, will be tough on astronauts, exposing them to high radiation loads, bone-wasting microgravity and other hazards for several years at a time. But these pioneers should still be able to make it back to Earth in relatively good nick, agency officials have said.

It might be a different story for those who choose not to come home, however. If we want to stay safe and healthy while living permanently on Mars, or any other world beyond our home planet, we may need to make some tweaks to our species' basic blueprint, experts say.

Related: Space radiation threat to astronauts explained (infographic)

Genetic engineering and other advanced technologies "may need to come into play if people want to live and work and thrive, and establish their family, and stay on Mars," Kennda Lynch, an astrobiologist and geomicrobiologist at the Lunar and Planetary Institute in Houston, said on May 12 during a webinar hosted by the New York Academy of Sciences called "Alienating Mars: Challenges of Space Colonization." 

"That's when these kinds of technologies might be critical or necessary," she said.

Coming soon?

Genetic enhancement may not be restricted to the pages of sci-fi novels for much longer. For example, scientists have already inserted genes from tardigrades — tiny, adorable and famously tough animals that can survive the vacuum of space — into human cells in the laboratory. The engineered cells exhibited a greater resistance to radiation than their normal counterparts, said fellow webinar participant Christopher Mason, a geneticist at Weill Cornell Medicine, the medical school of Cornell University in New York City.

NASA and other space agencies already take measures to protect their astronauts physically, via spacecraft shielding, and pharmacologically via a variety of medicines. So, it's not a huge conceptual leap to consider protecting them genetically as well, provided that these measures are proven to be safe, Mason said.

"And are we maybe ethically bound to do so?" he said during the webinar. "I think if it's a long enough mission, you might have to do something, assuming it's safe, which we can't say yet."

Tardigrades and "extremophile" microbes, such as the radiation-resistant bacterium Deinococcus radiodurans, "are a great, basically natural reservoir of amazing traits and talents in biology," added Mason, who has been studying the effects of long-term spaceflight on NASA astronaut Scott Kelly. (Kelly spent nearly a year aboard the International Space Station in 2015 and 2016.) "Maybe we use some of them."

Harnessing these traits might also someday allow astronauts to journey farther than Mars, out to some even more exotic and dangerous cosmic locales. For instance, a crewed journey to the Jupiter moon Europa, which harbors a huge ocean beneath its icy shell, is out of the question at the moment. In addition to being very cold, Europa lies in the heart of Jupiter's powerful radiation belts.

"If we ever get there, those are the cases where the human body would be almost completely fried by the amount of radiation," Mason said. "There, it would be certain death unless you did something, including every kind of shielding you could possibly provide."

Genetic engineering at least lets us consider the possibility of sending astronauts to Europa, which is widely regarded as one of the solar system's best bets to harbor alien life. (The Jovian satellite is a high priority for NASA's robotic program of planetary exploration. In the mid-2020s, the agency will launch a mission called Europa Clipper, which will assess the moon's habitability during dozens of flybys. And Congress has ordered NASA to develop a robotic Europa lander as well, though this remains a concept mission at the moment.)

Related: The 6 most likely places to find alien life

Not just us

Genetic engineering almost certainly won't be restricted to pioneering astronauts and colonists. Recent advances in synthetic biology herald a future in which "designer microbes" help colonists establish a foothold on the Red Planet, Lynch said.

"These are some of the things that we can actually do to help us make things we need, help us make materials to build our habitats," she said. "And these are a lot of things that scientists are researching right now — to create these kinds of things for our trip to Mars."

Some researchers and exploration advocates have even suggested using designer microbes to terraform Mars, turning it into a world much more comfortable for humans. This possibility obviously raises big ethical questions, especially considering that Mars may have hosted life in the ancient past and might still host it today, in subsurface lakes or aquifers. (Permanently changing our own genomes for radiation protection or any other reason may also strike some folks as ethically dubious, of course.)

Most astrobiologists argue against terraforming Mars, stressing that we don't want to snuff out or fundamentally alter a native ecosystem that may have arisen on the Red Planet. That would be both unethical and unscientific, Lynch said.

After all, she said, one of the main reasons we're exploring Mars is to determine if Earth is the only world to host life. 

"And how can we do that if we go and change the planet before we go and find out if life actually was living there?" Lynch said.

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook

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Mike Wall
Senior Space Writer

Michael Wall is a Senior Space Writer with Space.com and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.

  • HumboldtRick
    Insanity. We can't even manage our own planet. We don't belong on other worlds until we can live on our own without destroying it.
    Reply
  • netdragon
    I suspect this is pretty typical. For all we know, we may be hybrids created to help colonize Earth.
    Reply
  • netdragon
    HumboldtRick said:
    Insanity. We can't even manage our own planet. We don't belong on other worlds until we can live on our own without destroying it.
    I don't think we have much of a choice. It may save our species and Earth to colonize places without physical life for spillover population. We'll need to figure out how to decrease our impact on Earth in parallel.

    What I'd be more concerned about is damage we could do to other civilizations in the galaxy if we get FTL, based on our history on Earth.
    Reply
  • Edward Coulter
    HumboldtRick said:
    Insanity. We can't even manage our own planet. We don't belong on other worlds until we can live on our own without destroying it.
    That will never happen. Who could decide when all earth's people are living together amicably. Get over it and get on with the exploration and habitation. Our species needs to learn but sitting here (on earth) waiting for things to quiet down would mean never getting off the earth, never exploring other planets and never developing our minds. Stagnation is the alternative you are offering. I would not become much upset if we managed accidentally to destroy a herd of martian bacteria but it is more likely they would destroy the explorer. After all, they are the adapted ones.

    Humans are not going to destroy this earth. Right they have done plenty damage but we are learning how to deal with it. One way to deal with it is to reduce our population by 3 to 4 billion people. Our high population is the enemy, as each person has a demand for resources which we are not going to be able to meet. We are not meeting the basic needs of billions now and it continues to get worse. How many cars do you own? How many do you absolutely NEED?

    A far as damaging other civilizations is concerned, I am much more concerned that once they know we are here they will wage a war of extinction on us. They might more likely have the mind-set of the Japanese or Germans of the last century but with the super-weapons of an advanced civilization. Keep our heads down.
    Reply
  • TonyO
    Isn't this Transhumanism or Posthumanism?
    Reply
  • Space Doc
    TonyO said:
    Isn't this Transhumanism or Posthumanism?

    Yes. :-|
    Reply
  • Space Doc
    "Genetic engineering and other advanced technologies "may need to come into play if people want to live and work and thrive, and establish their family, and stay on Mars," Kennda Lynch, an astrobiologist and geomicrobiologist at the Lunar and Planetary Institute in Houston"

    An astrobiologist/geomicrobiologist knows exactly ZERO about medicine and human genetics. LOL! :D
    Reply
  • KnowBuddy
    people can be so so so stupid. We can't get together to fix our challenges here on earth so we distract ourselves by wasting time and money on some ridiculous star wars fantasy
    Reply
  • Ephasius
    Underground is where to start and lessening the adaptive and development cycle times. This can be exploited here too. Eye adjustment for low lighting and mental performance should be step 1. Anywhere, caretaker colonies could be developed to assist specific ecologies.
    Reply
  • Ephasius
    KnowBuddy said:
    people can be so so so stupid. We can't get together to fix our challenges here on earth so we distract ourselves by wasting time and money on some ridiculous star wars fantasy

    Mankind has no shortage of flaws, but an opportunity to create something more adaptable makes a logical starting point when looking at the long term picture of survival and growth.
    Reply