On Mars, snow falls in the early morning a Canadian-led research team has reported.
"We found ice clouds and precipitation that were surprisingly Earth-like - certainly more so than expected," said Jim Whiteway, the professor at Toronto's York University who headed the study published Friday in Science. It was the first time precipitation had been observed falling to the ground on Mars.
Whiteway told CBC News that the Martian clouds are similar to very thin clouds seen in Earth's Arctic in the winter.
NASA first reported Phoenix's observations of falling snow in September, but at that time it wasn't clear whether the snow ever made it to the ground. Now that the data has been analyzed, researchers think they have a better understanding of the water cycle on Mars.
During the day, they suggest, the water vapour is lifted by turbulence and convection. At night, as the temperature drops below the frost point, it forms
ice crystal clouds and falls back to the surface as snow.
http://www.cbc.ca/technology/story/2009/07/03/tech-snow-mars-whiteway-clouds.html
