Scientists say colonisation in outer space is at risk as human sperm becomes disoriented in microgravity
Scientists say that colonization in space is at risk because human sperm loses its orientation in the zero-gravity environment.
A study conducted at the University of Adelaide and published in Communications Biology examined how sperm from several mammalian species behaved in simulated zero-gravity conditions, raising questions about the feasibility of having children beyond Earth.
Researchers used rotating laboratory equipment to mimic weightlessness and observed how sperm navigated a maze designed to replicate the female reproductive system.
The findings showed that significantly fewer sperm were able to successfully complete the route in microgravity compared to normal Earth conditions, although their swimming abilities remained unchanged.
The research has implications for Elon Musk’s long-term space colonization plans, including his goals to populate Mars.
Speaking about the findings, study leader Dr. “We were able to show for the first time that gravity is an important factor in the ability of sperm to navigate a channel such as the reproductive tract,” said Nicole McPherson.
He added: “We observed a significant reduction in the number of sperm that were able to successfully find their way through the chamber maze in microgravity conditions compared to normal gravity.”
Dr McPherson continued: “This occurred in all models, although there was no change in the way the sperm physically moved. This suggests that the loss of orientation was not due to a change in motility but rather to other factors.”
The research also identified a potential mitigating factor.
Scientists found that progesterone, a hormone secreted by eggs that helps guide sperm, improves navigation in microgravity; This suggests that chemical signals may still aid fertilization even in the absence of gravity.
However, the team said more research is needed to determine how effective this mechanism would be in real space environments.
The project involved collaboration with the Andy Thomas Space Resources Center, where scientists explored the practical challenges of sustaining human life beyond Earth.
Associate Professor John Culton said: “As we move towards becoming a space-faring or multi-planetary species, it is critical to understand how microgravity affects the early stages of reproduction.”
Additional findings from related studies indicate that reproduction in space faces many obstacles. Experiments involving animal fertilization in simulated microgravity showed a significant decrease in successful outcomes; mouse eggs experienced reduced fertilization rates after short exposure periods.
Long-term exposure led to developmental problems and reduced cell growth in embryos, although some healthy embryos were still observed.
The researchers also highlighted broader environmental risks associated with space settlement, including exposure to radiation that can damage DNA and increase the risk of cancer, as well as the impact of microgravity on hormones and embryonic development.
Other factors such as hazardous dust, spacecraft pollution, limited resources, and psychological stress were also identified as additional challenges to maternal and fetal health.
