See-Through Space Worms May Hold the Key to Living on Mars

​Tiny, see-through, floating worms could provide answers that will help us plan manned missions to Mars and beyond.

Those answers are still a few years away, but a team of resear​chers at the University of Delaware is preparing to send worms into space to study the effects of reduced and zero gravity. Right now, the team is doing ground studies to refine the experiments that will take place aboard the International Space Station (ISS) when NASA sends the microscopic invertebrates into orbit in approximately two years.

So, why worms? Well, the team isn't focusing on the immediate effects of reduced and zero gravity on the human body—we actually know quite ​a lot about that due to the hundreds of humans we've sent up to space—they're studying how gravity might affect our genes across generations through epigenetics.

"Epigenetics is similar to genetics, but instead of inheriting DNA, think of it as inheriting little switches that turn genes off and on," explained Chandran Sabanayagam, one of the researchers and an associate scientist at the Delaware Biotechnology Institute.

The researchers want to see whether reduced or zero gravity could alter those little switches, turning them on or off when the next generation is born.

"The organism is going to want to adapt to its new environment and it's not going to adapt by deleting genes or somehow making new genes, it's going to adapt by switching certain genes on and certain genes off," Sabanayagam told me. Unlike evolution, which takes millions of years, these changes in switching genes on and off can occur in just one generation.

To suss out what changes might be happening, the researchers have started by putting the worms (caenorhabditas elegans to be specific) into simulated reduced gravity and microgravity conditions. Reduced gravity is simulated by placing the worms in water—they experience about 8 percent of their normal weight when living in liquid—while zero gravity is simulated by keeping the worms suspended in a sort of perpetual fall:

"Think about taking a bottle of water and putting an object in it. The object begins to fall to the bottom but before it hits the bottom, you flip the bottle upside down," Sabanayagam said. "Before it hits the bottom, you flip it again. If you keep doing it by rotating the liquid vessel, then the worms' trajectory is like an orbit."

They'll then study the worms' DNA to see which switches are flipping, identify which genes they affect, and mark them to study when the worms go to space. The team will then be able to compare the space worms to ones in their lab on Earth and the subsequent generations to observe the effects.

Okay, but what does this have to do with living on Mars? Well these teeny, transluscent worms actually share 70 percent of their DNA with humans, so what the researchers learn about zero gravity's effects on their genes can be translated to help us understand its effects on our own.

It may seem easier just to study the genes of humans aboard the ISS but there are other benefits to the worms. Their life cycle is only about two weeks, so you don't have to wait long to see effects over multiple generations. And unlike humans, they essential produce clones of themselves when they reproduce, making for more direct DNA comparisons across generations. They're also small (adults are less than 1 millimeter long), so it's easy to bring a few hundred of them into space. Oh, and they can live in water or on land, so that spinning water bottle experiment is no biggie.

While we've figured out how to successfully send humans into space for short stints without any long-term damage, there's still a lot we don't know about how living in zero gravity could affect humans long term, especially over multiple generations. These little space worms aren't the only exper​iment NASA is conducting to try to figure that out, but they may hold one of the keys to unlocking the mystery of gravity's long game. If we're want to start colonizing Mars (or Kep​ler-438b), we're going to want to figure it out.