Scientists have discovered that silk can withstand temperatures as cold as space.
Silk is a natural polymer fibre, a large molecule made of lots of subunits. Most other polymer fibres get brittle in the cold.
But scientists from the universities of Oxford, Shanghai and Beijing discovered natural silks can withstand the cold and some even get stronger the colder they get.
The team examined the behaviour and function of several animal silks cooled down to liquid nitrogen temperature of -196 C and found that silk's toughness is based on its tiny fibres.
The fibres studied included spider silks, but focused on the thicker fibres of the wild silkworm Antheraea pernyi.
Silkworms produce silk fibres from their jaws, they produce the threads to make cocoons.
Silk biologist Fritz Vollrath of Oxford University said: "No-one would have thought that toughness at cryogenic temperatures would be among [silk's] properties."
The scientists think the silk could be used to create new materials for use in some of Earth's coldest regions, or even the depths of chilly space.