On Tue, 27 Jan 2004 09:48:38 -0600, "Paul F. Dietz"
wrote:

Cardman wrote:

A lava flow according to them, but yes there is water everywhere. Does
not that ground look a touch wet to you?

No. BTW, liquid water cannot exist over almost all the Martian surface --
the pressure is too low.

Well, there is one theory that morning heating of the top soil causes
a brief water ice change to flowing water before the low atmospheric
pressure causes it to evaporate.

Due to the rapid evaporation of water ice in the top soil, then this
would increase atmospheric density in the few centimeters above the
top soil before a brief time.

Thus very cold water could flow.

I believe that's the case at that location.

My point more goes along the line that Odyssey findings indicate that
water content in the top few meters of soil exceeds any scientist's
expectations.

If I recall correctly, then a site like this could have around 30%
water ice content in the soil, where it is assumed to be mostly
contained below the immediate top soil in ways that they do not fully
understand.

In other colder parts of Mars the water ice content is assumed to even
exceed 50% of the soil mass even going up to about 70%.

One theory to explain why there is so much water ice in the top soil
is that there is simply tons of liquid water in the lower layers,
which is kept warm by the top blanket and any remaining heating from
the core of Mars.

The other factor is that as there is crap loads of water on Mars, then
this simply does not go away due to the low pressure.

So what all these factors together can tell you is that maybe warmish
water deep below Mars is slowly rising to the surface, where of course
it would quickly cool.

However, the further warmer water below this is constantly pushing
upwards and is warming this above cooler water.

And so when you get to the surface there is a sudden change where this
low atmospheric pressure causes a sudden change from water ice to a
gas as it evaporated away.

The thing in this is that there is always more water coming up from
below during the early daylight hours, which is constantly keeping the
top soil packed with water ice from below.

Naturally, when things turn dark and gets a lot colder, then so can
your water in the atmosphere return to the ground.

My point I guess is that scientists have a very long way to go before
they understand how Mars works, where this vast volume of water in the
top soil must be moving around somehow.

Since they do not yet understand how there could be so much water ice
in the top soil, then it is a little early to say that the top soil
does not look wet.

It looks a touch wet to me.

Cardman
http://www.cardman.com
http://www.cardman.co.uk