Worms in Space sounds like the title of some cheesy Sci-Fi movie from the 1950’s, but scientists actually sent worms to space to test their ability to grow and to adapt to a weightless environment.
Researchers from Tuft University sent a species of flatworms that has the ability to grow a new head if it loses one to space. Since a flatworm on Earth can lose its head and simply grow a new one, scientists sent some with amputated heads, and others that were fully intact. The worms were transported as part of the payload on a SpaceX mission, and spent five weeks on the International Space Station, before they were shipped back to Earth. SpaceX is the company that conducts missions under contract with NASA founded by Elon Musk, who also started the Tesla Motor Company.
The report from Tuft University said that the worms with amputated heads exhibited an amazing, rare phenomena. They grew back two heads instead of just one. This never occurs on Earth. Scientists who have studied 15,000 worms over an 18-year period have never seen even a single incidence of a flatworm growing back two heads when one was lost.
After the worms returned to Earth, they were studied for twenty months where the biological differences between the space worms and worms kept on Earth were analyzed. Some of the space worms that grew two heads had them amputated again when they returned to Earth. To the scientists’ amazement, they grew back two heads again, meaning there were permanent genetic mutations made from the time they were sent to space.
Another surprising occurrence was that some of the whole worms sent from Earth to space experienced spontaneous fission. This means they split into two identical copies of themselves, though none of the worms on Earth split into clones of themselves. Scientists are not sure if it was the space travel that caused this, or if it was caused by the differences in temperature experienced by the worms sent to space when compared to the control worms on Earth.
When the worms sent to space first returned to Earth and were placed in normal conditions in Petri dishes filled with natural spring water (their usual living environment) they had a bad reaction. They curled up, were partially paralyzed, remained mostly immobile at first, and needed about two hours to become re-acclimated to the Earth’s conditions. This shows there was a strong adaptive effect that the worms sent to space underwent that seriously changed their responses to certain living conditions, which they were previously quite used to experiencing. Flatworms of this species are especially interesting because they can rapidly change in response to certain stimuli.
The worms that had been sent to space also exhibited a preference for being in light after they returned to Earth. When compared to the control worms on Earth, the space worms liked to stay in the darkness for 70.5 % of the time and the Earth control worms preferred darkness 95.5% of the time.
The meaningful results from this study will help scientists understand the microbiological, morphological, and behavioral changes that occur in weightless environments, and will help scientists further understand the requirements needed for human beings to spend extended periods traveling in space.