There are currently six astronauts on board the International Space Station, but they are not alone. NASA has created a comprehensive catalogue of all the microbes on the space station, and found it is teeming with non-human life.
The agency hopes this knowledge will help it develop safety precautions for future long-term space travel, such as sending humans to Mars.
Microbes thrive on the ISS thanks to its unique combination of microgravity, radiation and tightly confined living space. A lack of competition from microbes normally found on the ground also …