Sperm are disoriented in space

The conquest of space underlies the idea that humanity could expand into the cosmos and, inevitably, begin to reproduce there. What is the place of sexuality in this project? The question is not unrelated to biology, because it is still necessary power reproduce in space. However, this may be compromised.

Spanish researchers took 15 samples of human sperm in order to divide it into two groups: one went into space, while the other remained on Earth. Specifically, the samples were sent in parabolic flights; in microgravity therefore. As they report in a study published in October 2024, they were able to identify a significant difference between the two.

Decreased motility, decreased vitality

Sperm exposed to microgravity did not die, and there is some good news: their DNA was not affected and their shape did not change. However, they suffered from two significant deteriorations:

• A decrease in motility (the ability to move, find one’s way, movement);
• A decrease in vitality: fewer viable spermatozoa in total number.

On the motility side, the most problematic was a reduction in the ability of sperm to quickly perform curvilinear movements. In short, they struggle to find their way and are slower. This greatly reduces the fertilization capacity, since it is more difficult for them to reach their goal. Especially since, as the authors of the study write, “ the negative consequences would be even greater if exposure [à la microgravité] was longer. »

As for the causes of these changes in human sperm in microgravity conditions, there is no explanation for the moment, as this type of research is only at the beginning.

But reproduction risks being a delicate issue. This is not the first study on the subject to suggest problems, since mouse embryos were not viable in this environment.

This is not the only negative impact of space on health: some astronauts lose their nails, experience a significant drop in red blood cells and their brain can cope very poorly with the experience. Not to mention food (in space, salads can carry diseases, because plants are susceptible to bacteria in zero gravity).