of water-ice, rather than carbon dioxide-ice because the temperature for forming carbon dioxide ice is much lower—less than -120 °C. As a result of the mission, it is now believed that water ice (snow) would have accumulated later in the year at this location. Scientists think that water ice was transported downward by snow at night. It sublimated (went directly from ice to vapor) in the morning. Throughout the day convection and turbulence mixed it back into the atmosphere. Climate cycles Interpretation of the data transmitted from the Phoenix craft was published in the journal Science. As per the peer reviewed data the presence of water ice has been confirmed and that the site had a wetter and warmer climate in the recent past. Finding calcium carbonate in the Martian soil leads scientists to believe that the site had been wet or damp in the geological past. During seasonal or longer period diurnal cycles water may have been present as thin films. The tilt or obliquity of Mars changes far more than the Earth; hence times of higher humidity are probable. Interactive Mars map See also Lakes on Mars References Further reading Martel, L.M.V. (July, 2003) Ancient Floodwaters and Seas on Mars. Planetary Science Research Discoveries. http://www.psrd.hawaii.edu/July03/MartianSea.html External links Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention Plains on Mars Mare Boreum quadrangle Ismenius Lacus quadrangle