If space travel wasn't hard enough, imagine trying to do it with two heads.
A flatworm sent to the International Space Station aboard a SpaceX rocket in 2015 as part of a biological study grew a second head after the first one had been partially amputated before launch.
Flatworms are often sent into space because of their regenerative capabilities, but this particular one (there were both whole and amputated worms sent into space) was able to grow a second head.
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