IN 2018, A spacecraft departed the International Space Station carrying unusual cargo: colonies of bacteria that had spent years hanging out in space. These intrepid microbes were the final samples to be returned to Earth as part of the Tanpopo mission, a Japanese astrobiology experiment studying the effects of the space environment on simple organisms. If the microbes survived long-term exposure to the vacuum, it would be a significant boost for a controversial theory known as panspermia, which suggests that life hitches a ride between planets on asteroids, comets, and space dust

.
A Ball of Bacteria Survived for 3 Years ... in Space! | WIRED