Further on liquid water in Solis Lacus, Mars.

The latest released images from Mars Express show some interesting
images of Mars in Claritas Fossae and Solis Planum, another term for
Solis Lacus. They show low lying clouds over Solis:

The grabens of Claritas Fossae
http://www.esa.int/export/SPECIALS/M....html#subhead1

The next to last image gives a perspective view and the appearance is
that the clouds contact the higher elevation portions of the area.
These images were taken in mid-southern Autumn and it is possible
during the hottest portion of the day the ice crystals in the clouds
could melt to liquid on contact with ground.
Since on Earth the phenomenon of super-cooling allows water droplets
in clouds and fogs to remain liquid even down to -40 C, it is possible
these clouds consist of liquid water close to the surface even at
below freezing temperatures.


Bob Clark


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From: Robert Clark )
Subject: Will Mars Odyssey prove liquid water in Solis Lacus, Mars?
Newsgroups: sci.astro
Date: 2003-08-08 21:51:54 PST


The following was posted to uplink.space.com in regards to a new paper
by Barlow and Perez:

Martian impact crater ejecta morphologies as indicators of the
distribution of subsurface volatiles.
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. E8, 5085, 2003
http://www.agu.org/pubs/crossref/200...JE002036.shtml


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exoscientist
08/09/03 12:33 AM
JGR-Planets (Articles in Press) - August 9, 2003 [
AlexBlackwell]

Interesting that Barlow and Perez say the fluidized ejecta pattern
generally follows the GRS hydrogen readings. One area where it does
not is in Solis Planum.
Barlow has discussed the fact that Solis was a near- equatorial site
that based on fluidized ejecta patterns would appear to have
near-surface water or ice:

Mars appears to have an underground ice reservoir located in the Solis
Planum region.
By Leonard David
Senior Space Writer
posted: 04:00 am ET
20 September 2000
"The team took a hard look at the smooth plains of the Solis Planum
region on Mars. It is pockmarked with craters and ejecta patterns
consistent, Barlow said, with varying amounts of subsurface water,
both in liquid and ice form.
"Certain crater morphologies indicate ice and other craters, we feel,
are impacts into liquid reservoirs. We see both types in that area.
Water may also be close to the surface in that area, underneath the
ice layer," Barlow said.
"We did not find another big reservoir like the one we found south of
Valles Marineris. This seems to be the biggest one that we've
identified," Barlow said."
http://www.space.com/scienceastronom...ce_000920.html

Mars Watering Hole Found, Scientists Say.
By Leonard David
Senior Space Writer
posted: 03:00 pm ET
13 August 2001
http://space.com/scienceastronomy/so...ce_010813.html

However, the GRS readings suggest Solis to be the driest spot on the
planet:

SEASONAL CO2 OBSERVATIONS ON NORTH AND SOUTH OF MARS AS SEEN BY HEND
(MARS ODYSSEY) AND MOLA (MGS).
Lunar and Planetary Science XXXIV (2003) 1103.pdf
"We averaged the neutron flux within given
latitude belt and studied the dependence of
averaged neutron flux versus solar longitude
(Ls). The normalization was used on the
maximum flux of neutrons, which is
observed in the equatorial region of Mars
near Solis Planum. This region may be
interpreted as the driest surface on Mars."
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1103.pdf

A possible cause for this discrepancy is suggested by earlier Viking
era evidence for water in Solis. This earlier evidence consisted of
water vapor measurements and radar reflectivity measurements both
separately and independently showing variable amounts of water in
Solis depending on season.
The key fact here is that the GRS readings of Solis have not yet been
made when Solis was shown by these earlier measurements to have the
highest water indications. It is also interesting that one of these,
the radar measurements, showed Solis to have low water amounts outside
the high water period, consistent with the GRS readings.

*This period of the highest water amounts in Solis occurred in middle
to late southern Spring and extending into early Summer, as Mars
reaches perihelion*.

However, the intepretation of this Viking era data showing water in
Solis has been disputed. For example, the high radar reflectivity
measurements instead of being due to liquid water brines have been
suggested to be due to Fe containing dust that changes seasonally.
The time period of the high water readings in Solis occurs this
month. If the GRS readings this month suddenly show Solis becoming one
of the wettest areas on Mars, at least among the equatorial sites,
rather than the driest, than I think this will be dramatic indications
of water and indeed *liquid* water on Mars.


Bob Clark

cf.

From: Robert Clark )
Subject: Liquid water in Solis Lacus on Mars.
Newsgroups: sci.astro, sci.astro.seti, sci.geo.geology,
alt.sci.planetary
Date: 2001-03-13 10:42:31 PST
http://groups.google.com/groups?th=c1467cffcf0a00de
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