Scientists Uncover a New Way to Keep Astronauts Fit on Mars, Thanks to Mice

As NASA and the China National Space Agency plan missions to Mars, one major concern is how the planet’s weaker gravity will affect astronauts. A recent study sheds light on the potential risks, particularly for our muscles. Since gravity on Mars is only about 38% of what we have on Earth, the effects could be serious over time. New research involving mice aboard the International Space Station (ISS) is giving us important clues.

Sending humans to Mars has been a goal for decades, but it comes with a whole set of challenges, especially when it comes to astronaut health. One of the biggest unknowns has been the impact of long-term exposure to reduced gravity, like what would happen during the months-long trip to Mars and once astronauts arrive.

Why Muscles Matter in Space

Our skeletal muscles make up more than 40% of our body mass, and they’re essential for everything from basic movement to metabolic health. But when we’re in space, where there’s no gravity, muscles don’t get the same workout as they do on Earth. This is why astronauts face muscle atrophy during long missions. While we’ve already seen the effects of microgravity in space stations like the ISS, the gravity on the Red Planet is different.

A team of researchers, including scientists from JAXA and the University of Tsukuba, set out to better understand how reduced gravity, like that on Mars, affects muscle tissue. The results are especially important because astronauts will need to keep their muscles strong for tasks like moving, carrying equipment, and even just staying healthy during long missions.

Testing Martian Gravity on Mice

To understand how different gravity levels impact muscle health, the researchers ran an experiment with 24 mice aboard the ISS. As explained in a latest research, published in Science Advances, these mice were exposed to four different gravity conditions: microgravity, 0.33 g (close to Mars’ gravity), 0.67 g, and 1 g (Earth’s gravity). After 28 days, the mice were analyzed for muscle strength, size, and performance. As Professor Marie Mortreux from the University of Rhode Island pointed out:

“We used gravity levels that were equally separated, to have a better picture of the dose-response of each system to gravity,” he explained in a statement available from the University of Rhode Island. “The test group that was exposed to 0.33g was extremely close to Martian gravity (0.38g). Our findings for that group can be translated into actions to enable Mars exploration.”

Mars Missions: Are We Ready Yet?

One exciting takeaway from the study is that scientists discovered several biomarkers, metabolites in the blood that change depending on gravity. These could be used in the future to monitor astronauts’ muscle health during space missions, making it easier to track their physical condition and catch any issues early on.

As Mortreux mentioned, having these biomarkers gives us a valuable tool for space travel. It means that during long missions to Mars, astronauts could be monitored in real-time to see how their muscles are adapting to the lower gravity.

“Since this mission aimed to assess gravity as a continuum, we were perfectly positioned to see if our ground-based results had similar outcomes when reduced mechanical loading was applied in orbit,” he added.