Mars Express an ESA probe that has been orbiting Mars for several years has measured the water content of the Martian atmosphere using it’s SPICAM spectrometer. IT found that it is above that of saturation a state called supersaturating. This is the first time this type of measurement has been made on a global scale. The result will help in prove our understanding of Mar’s weather.
This result is also consistent with a catastrophic model of Martian geology. If Mar’s atmosphere had temporarily been raised to allow surface water by dust from impacts and volcanic activity, when Martian atmospheric pressure dropped as this dust settled the resulting evaporation would supersaturated atmosphere. This state would continue because the low pressure makes rain impossible so the only way to reduce it is for the water to slowly bleed off into space.
This is consistent with a young catastrophic model of Mars that is consistent with the Biblical account.