Lakes On Mars

There are several items of gas properties that may or may not be right in your description of the atmosphere and "lakes" of Mars. If you do the math it may be that H2O gas is too light for the gravity field of Mars to hold. But, if Mars can hold H2O it should also be able to hold N2 & O2 molecules since the mole wt is greater. Do you see these molecules in the atmosphere of Mars? Maybe all the O2 is locked up in CO2 on mars? Could the solid state of all these molecules could be stored somewhere on Mars?

One possibility; hypersaline H20? How far can brine/ minerals in water lower it's freezing point in Mars STP? Apparently, ground temps(as opposed to atmospheric temp. only a few feet high) can easily become high enough to melt water ice.
Another possibility: liquid CO2?? H20 and CO2 at different times, same locations depending on season/ temperature, originating from subsurface sources? How much(if any) can the aforementioned brines affect volatility of a hypothetical CO2 lake at Martian STP??
Any other suggestions??

Re: Questions

At a "high" temperature of 60 degrees Fahrenheit, the mean velocity of water molecules is about 0.52 km/sec whereas the escape velocity for Mars is 5.03 km/sec. There should not be gravitational escape by water vapor. N2 and O2 are present at 2.7% and 0.13% in the atmosphere. Under Martian STP they would not be solid or liquid. Although the cold temperature would promote their solubility in the aqueous phase, their extremely low partial pressures counteracts this effect. Their solubility would be in the 10 to 100 ppm range.

A hypersaline H2O would be the probable generic description of a lake. This would include the particular case of nitrite - nitrate. Take any metal ion and any anion and you have a salt. The lakes probably have a multitude of salts.

An upwelling of heat from below the lake is a very plausible alternative. If this heat brought the lake anywhere near 32 degrees Fahrenheit, the possible compositions would be very broad.

At Martian STP, there would be no liquid CO2. Its triple point is 75.1 psia and -56.6 degrees Celsius. Carbonates could play a very minor role in the lake composition but could not be the commanding ingredient.


Gregg Wilson