Astronauts’ Memories of Earth’s Gravity May Influence How They Move and Hold Objects, Even After Months in Space

Examining the fine motor skills of space travelers can help improve safety for future missions, scientists say

Sara Hashemi | Daily Correspondent

April 21, 2026

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As humanity heads back to the moon, scientists are trying to understand the impact that being in space can have on the brain. Research has shown that spaceflight can temporarily change the brain’s position and shape, while long-term space travel can re-wire human brains for months. Now, a new study has found that microgravity affects how astronauts grip objects, revealing insights into how the brain adapts to weightlessness.

The work, published in the Journal of Neuroscience on April 20, looked at how astronauts’ motor skills were affected when moving between Earth and space. The findings have important safety implications, the researchers say, as incorrectly gripping an object in space could have grave consequences.

To conduct the study, Lefèvre and his colleagues analyzed the grip dynamics and movements of 11 astronauts—two female and nine male—who lived aboard the International Space Station (ISS) for stints of at least five months each. The astronauts performed repetitive arm movements while gripping objects with the thumb and index finger on Earth and during spaceflight.

“What we observed was totally unexpected,” study co-author Philippe Lefèvre, a biomedical engineer at the Catholic University of Louvain in Belgium, says to Chelsea Gohd at Space.com.

The team found that the memory of gravity impacted how astronauts manipulated objects on the station, even after months in space—they would use a stronger than necessary grip, as if thinking the item would weigh at least as much as it does on Earth. The astronauts tended to overcompensate in microgravity, even though they knew rationally that the object would feel weightless. They also moved their arms more slowly in space and gripped harder when an object was moving more quickly.

“The fact that we were exposed to gravity from early childhood for years and decades—we cannot forget it, even after five to six months,” Lefèvre says to Scientific American’s Claire Cameron. The findings suggest that “astronauts tend to apply a larger safety margin” than what is necessary, Lionel Bringoux, a researcher at the Institute of Movement Sciences at Aix-Marseille University in France who was not involved in the work, says to the publication.

Shortly after the astronauts returned to Earth, they continued to incorrectly predict the weight of objects. But they quickly adjusted, the scientists found. “The adaptation that we had to gravity for decades [means] we do not fully adapt to microgravity, but the advantage is that when we go back to Earth, we readapt that very quickly to the Earth’s environment,” Lefèvre says to Scientific American.

Understanding how our brains respond to gravitational changes is important for future space ventures. With any human missions to the moon or Mars, scientists will need to understand the risks of objects slipping from a human’s grasp—if astronauts are landing on the moon, for instance, they might need training that helps them adapt to partial gravity, Lefèvre says to Theo Farrant at Euronews.

Astronauts need to grip objects correctly to conduct experiments and manipulate other devices. The kinetic energy of an object—or the energy it gets from its speed of movement and mass—affects both the risk of it slipping and the ramifications of a slip, per the paper.

“Even if the risk of slippage is low, the consequence of slippage would be really dramatic,” Lefèvre explains to Space.com. “If you move at high speed [with] a big object onboard the ISS, and you lose the grip, the object will keep going. It’s gonna hit something, and it could be dramatic in terms of safety.”

Sara Hashemi | Read More

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.