These are called “nanoceria” – tiny ceramic particles which mimic the behaviour of biological enzymes.
In a recent experiment aboard the International Space Station and conducted by researchers from the European Space Agency, nanoceria were combined with living human cells and exposed to zero-gravity conditions for six days, before being frozen and shipped back to Earth inside a SpaceX Dragon spacecraft.
The material is set to be examined by researchers to see how it has been affected by radiation exposure, potentially offering clues to the hazards of long-distance space travel.