For astronauts toiling in the close quarters of the International Space Station or on a shuttle to Mars, an ordinary germ would be risky enough. But a recent experiment published in the Proceedings of the National Academy of Sciences has shown that a microbe can turn even more dangerous in space than on Earth. In that study, a bacterium particularly nasty for humans—salmonella—was shown to become more virulent after just 83 hours of growing in space.
The experiment on the space shuttle Atlantis was designed to explore how a lack of gravity affects disease-causing microbes in space. Astronauts aboard the space shuttle grew the salmonella, and back on Earth researchers used it to infect a group of mice. For comparison, bacteria grown in a laboratory on Earth in normal gravity infected another group of mice. The mice infected with the space-grown germs had a mortality rate almost three times higher ...
