Dry Venus-Humid Earth-Climate Changes on Mars

6 Dry Venus-Humid Earth-Climate Changes on Mars 

After having discussed the terrestrial planets we address to the question why their evolution was so different concerning their water content. One important criterion is of course the surface temperature. On Mercury, the temperatures are high because of its close position to the Sun and there cannot exist water besides, possibly, near the poles. 

It is reasonable to assume that Venus and Earth and even Mars accumulated similar amounts of primordial water during their accretion phase. So why did Venus lose its water  

Therefore, additional proxies for water content on a planet must be investigated. A study of the surface mineralogy of Venus could provide another proof for the existence of large amounts of water during its early evolution phase. Under the presence of water, hydrous minerals formed on or below its surface. However, these minerals are unstable under the extreme temperature and pressure conditions on the surface (Zolotov et al., 1997 [376]). 

Johnson and Fegley, 2000 [172], argued that the mineral tremolite might indicate a higher water content on early Venus. On Earth, tremolite is found in basic rocks in contact with siliceous carbonate rocks. One possible reaction for the formation is  

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