If Humans Live in Space, Will We Lose Our Skeletons?

Journeying to space is an honor bestowed upon a fortunate few, merely information technology comes with some seldom-discussed side effects. For instance, in the absenteeism of gravity, the human body tends to expand—painfully. Astronauts' faces swell up due to excess bodily fluids that no longer take to contend with gravity—a status known as "the Charlie Chocolate-brown consequence"—while forcing all sorts of liquids out their diverse face holes. Grody.

These occasionally gross and painful conditions are inescapable consequences of transplanting the homo torso into an alien environment. And they're perfect examples of how humans are Non designed to live and piece of work outside Earth's temper. But they generally merely concluding "a 24-hour interval or 2" and are modest prices to pay for a trip to the cosmos, right?

There's nonetheless much we don't empathize. NASA astronaut Scott Kelly lived aboard the International Space Station (ISS) for 340 days (the record belongs to Russian cosmonaut Valery Polyakov, who racked up 438 days) and the effects of his stay included os density loss of i.5 percent per month, eye shrinkage (the center shrinks since it doesn't have to work as difficult), radiation exposure (no protective ozone layer), vision problems (eyes adapt to operating in gravity), and even pare irritability (resulting from non constantly coming into contact with things).

While Captain Kelly's prolonged stay resulted in a lot of science, one yr for one individual is notwithstanding a very limited data set—especially if you consider the fourth dimension necessary for a human to travel throughout the solar system with current engineering.

As space exportation and colonization become increasingly viable prospects, we are forced to face a great unknown: what volition happen to our bodies after decades in space? We're kind of rolling the die on this 1, and what happens on the other side is anyone'due south guess. Things might even become super weird.

"Would we, in the future, fifty-fifty have skeletons anymore if we were up in space for a long time," pondered NASA astronaut Scott Parazynski, who stopped by PCMag's offices for our Q&A series The Convo to talk almost his new memoir The Heaven Below.

Bated from his five journeys to space, Parazynski is a medical doc who specializes in infinite physiology and is the co-founder of Bluish Marble Space, which aims to utilise technology to help humans explore space. "That'south such a crazy thing to retrieve nearly it. Only we have skeletons here on Earth to resist gravity. But without it, over many generations, we'd probably evolve in some crazy means."

NASA astronaut Scott Parazynski

This is non to say that astronauts or first-generation colonists are in immediate danger of turning into boneless goo. But it's not insane to question if their descendants will be. When placed in an alien environment, development tin can take some weird turns. Consider the Mexican tetra (AKA the "blind cavern fish"), which long ago found its way into a lightless subterranean surroundings and—over many generations—eventually lost its eyeballs as they became unnecessary drains on resources. Might a similar dropping of dead biologic weight occur in humans on a future space colony? Short answer: Nosotros have no friggin' clue.

At present, there are things like centripetal movement, which tin recreate gravity in a weightless environment (think A Infinite Odyssey or Interstellar), and could be implemented for whatsoever long-term human space habitat. However, the more immediate concern regarding gravity's consequence on our bodies will exist in an environment like Mars, where gravity is but about a third as robust.

Over the generations, human bodies living in low-gravity locations like the Ruddy Planet will change graphic symbol. This may sound like some inconsequential sci-fi pondering, but a man civilisation in space is closer than many realize. The good news is we should be able to engineer our way around whatsoever problems we face.

NASA astronaut Scott Parazynski

"Anything that we humans ready our mind to nosotros tin usually solve. And that seems like a very solvable problem," explains Parazynski. "You've seen all the artists' renditions of future Mars colonies with these modules on the surface of Mars, but they'd probably be cached for radiations protection. And we could do hydroponic plant growth—we tin excerpt water from the soil. There'due south actually a lot of water on Mars. We can then generate oxygen to breathe. We tin do a lot there. But it volition take infrastructure and time. And by the manner, transport money."

I don't think that future colonists will get formless jelly-people, but the fact that nosotros don't know for sure shows just how many unknowns at that place are about humanity'due south ability to survive outside Earth's protective bubble. It'south about fourth dimension we at least start to consider what our weird space future will look like.

The Convo is PCMag's interview series hosted by features editor Evan Dashevsky (@ haldash ). Each episode is broadcast live on PCMag's Facebook page , where viewers are invited to ask guests questions in the comments. Episodes are then posted on our YouTube folio and available every bit an audio podcast , which you can subscribe to on iTunes or the podcast platform of your choice.