Rocket engines could benefit from a natural Martian lubricant – but not to keep them oiled. A salty sludge that may be lubricating the ice caps of Mars could one day provide fuel.
The ice is too cold to flow normally. But if winds were to carry salty soil particles to the ice cap, they might gradually sink to form a briny bed, kept liquid by the planet’s warmth. This could allow the ice cap to flow like a glacier, say David Fisher at the Geological Survey of Canada in Ottawa, and colleagues.
Such brine would freeze as it moved toward lower temperatures at the edge of the ice cap, forming a ring of concentrated salt. This could one day be mined as a component of solid rocket fuel, says Fisher.