The formation of water frost is common on Earth, especially in winter when atmospheric water vapour condenses and freezes on the surface. On Mars, the atmosphere is about 100 times less dense than on Earth, but it too contains water vapour. The atmosphere on Mars contains 10,000 times less water vapour than on our planet, however, so icing is less likely.
The exchange of water between the surface and atmosphere of Mars is currently not well understood. The formation of frost would not only be an important clue for helping us understand the water cycle, but also for identifying key resources for potential future human exploration. Water is a necessary for life and could also be used as rocket fuel.
