Mount Everest has been preserving climbers' coughs and sneezes

Researchers from the University of Colorado Boulder analysed soil samples from Mount Everest.

They found microbial DNA associated with humans, including Staphylococcus and Streptococcus.

Most of the microbes they found were thought to be dormant, but had been conserved in 'deep-freeze collection zones' near areas of human activity.

This supports the idea that alien life could exist on other frozen planets.