While most of us would like nothing more than to jettison ourselves away from this planet, our feeble bodies are not meant to survive in the cold vacuum of space. Though astronauts spend years training to prepare for the rigors of the final frontier, we’ve only scratched the surface of understanding the physical affects of space on astronauts’ bodies, especially when it comes to their brains.

A new study backed by NASA utilized astronaut brain scans to better understand how spaceflight impacts what’s arguably the most important part of the body. According to the research — which was led by Medical University of South Carolina neuroradiologist Donna Roberts — astronauts’ brains might actually shift up in the skull as a result of prolonged exposure to microgravity conditions. The results have been published in the November 2 edition of the New England Journal of Medicine.

“Exposure to the space environment has permanent effects on humans that we simply do not understand,” Roberts says in a statement. “What astronauts experience in space must be mitigated to produce safer space travel for the public.”

Some physical consequences of microgravity are already pretty well-documented, such as bone and muscle loss. That’s why NASA astronauts exercise for about two hours a day aboard the International Space Station (ISS). For this study, the team took MRI scans of 34 astronauts — 18 had spent a few weeks aboard a space shuttle, and 16 spent roughly three months on the ISS. The researchers took brain scans of all the astronauts before and after their spaceflight, and found some interesting changes to their brains, especially in those who participated in longer missions.

Roberts and her team found that the parts of the brain most impacted by long-duration spaceflight are the frontal and parietal lobes, which control movement and other key functions. The brains of astronauts who flew on longer missions also seemed to shift upward, decreasing the amount of Cerebrospinal fluid (CSF) spaces between the brain and the skull. CSF serves as a “shock absorber” that protects the central nervous system, kind of like a buffer for the brain. Oddly enough, astronauts who flew on shorter duration missions did not exhibit these shifts in the brain.


Somehow, things got even weirder. About 94 percent of the astronauts who flew on long-duration missions showed a narrowing of the brain’s central sulcus, which is a groove near the top of the brain that separates the parietal and frontal lobes. About 18.8 percent of the astronauts who participated in short-duration flights also showed this unusual change. Right now it’s unclear what this means, so it’s definitely an open question for future studies to answer.

“We know these long-duration flights take a big toll on the astronauts and cosmonauts; however, we don’t know if the adverse effects on the body continue to progress or if they stabilize after some time in space,” Roberts says. “These are the questions that we are interested in addressing, especially what happens to the human brain and brain function?”

Brain scans from the study.

Hopefully, this study will help researchers better understand an ailment that affects 80 percent of astronauts who’ve participated in long-duration spaceflight called “visual impairment intracranial pressure syndrome,” or VIIP syndrome. No one really knows what causes VIIP, which is why it’s so difficult to treat. But in this study, three astronauts who showed symptoms of VIIP syndrome also experienced narrowing of the central sulcus. This could mean there’s some connection here worth exploring in further detail.

Studies like this one are especially important in the race to get to Mars. Before we send off astronauts on such a long trip, it’s important to know how months and even years in space will affect their bodies. That might shift the timeline of certain billionaires’ plans to get there, but hey, it’s always better to be safe.