Could bacterial life travel between planets, carrying life through the universe?
Some scientists think so – and an experiment has shown just how tough some bacteria are.
Researchers at University of Vienna in Austria found that a bacteria, Deinococcus radiodurans, survived for a whole year on a platform outside the International Space Station (ISS).
The researchers said the results could be important for future missions to Mars, allowing scientists to understand how long bacteria can survive on the outside of spacecraft.
They analysed how the bacteria survived the environment of outer space, resisting galactic cosmic and solar UV radiation, extreme vacuum, temperature fluctuations, desiccation, freezing and microgravity.
The idea of alien life spreading like ‘seeds’ through space isn’t new – the theory is known as panspermia.
The new research helps us understand just how far such organisms could travel, the University of Vienna team said.
Tetyana Milojevic, head of space biochemistry group at the university, said: “These investigations help us to understand the mechanisms and processes through which life can exist beyond Earth, expanding our knowledge to survive and adapt in the hostile environment of outer space.
“The results suggest that survival of D. radiodurans in LEO [low Earth orbit] for a longer period is possible due to its efficient molecular response system and indicate that even longer, farther journeys are achievable for organisms with such capabilities.”
The team wrote: “These results should be considered in the context of planetary protection concerns and the development of new sterilisation techniques for future space missions.”
In 2019, researchers tested a new drug-resistant coating on the International Space Station to fend off potential infections.
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They have warned that bacteria on the space station can get tougher, as they adapt to the harsh conditions in space – as they test a new antimicrobial coating to fight them off.
“Spaceflight can turn harmless bacteria into potential pathogens,” said senior study author Professor Elisabeth Grohmann, from Beuth University of Applied Sciences Berlin.
“Just as stress hormones leave astronauts vulnerable to infection, the bacteria they carry become hardier, developing thick protective coatings and resistance to antibiotics, and more vigorous, multiplying and metabolising faster.”
Scientists tested a new antimicrobial coating based on silver and ruthenium, which reduced levels of bacteria on contamination-prone surfaces.
Grohmann said: “After six months exposure on the ISS, no bacteria were recovered from AGXX-coated surfaces.”