Latest Mars Odyssey results suggest free water at equator on Mars.
Robert Clark
uplink.space.com in regards to a new paper that suggests clays may
explain the high levels of water detected by Mars Odyssey in some near
equatorial regions on Mars:
Stability of hydrous minerals on the martian surface.
David L. Bish, J. William Carey, David T. Vaniman and Steve J. Chipera
Los Alamos National Laboratory, Mail Stop D469, Los Alamos, NM 87545,
USA
Icarus, Volume 164, Issue 1, July 2003, Pages 96-103.
http://dx.doi.org/10.1016/S0019-1035(03)00140-4
A similar theory is proposed by Tetsuya Tokano:
Spatial inhomogeneity of the martian subsurface water distribution:
implication from a global water cycle model.
Tetsuya Tokano
DLR––Institut für Raumsimulation, 51170, Köln, Germany
Icarus, Volume 164, Issue 1, July 2003, Pages 50-78.
http://dx.doi.org/10.1016/S0019-1035(03)00105-2
Bob Clark
_________________________________________________________________________
exoscientist
07/19/03 04:09 AM
Re: Hydrous Minerals at Mid-latitudes of Mars
Thanks for the link. This might explain the variable amounts of
hydrogen dependent on season seen near the equator in the latest
Odyssey GRS reports:
Latest Odyssey results prove free water at equator.
exoscientist
06/27/03 11:24 AM
http://uplink.space.com/showflat.php?Cat=&Board=sciastro&Number=516193
This idea of clays on Mars containing water that could vary diurnally
according to day/night temperature fluctuations was also discussed in
reports by Bish et.al.:
WATER-BEARING MINERALS ON MARS: SOURCE OF OBSERVED MID-LATITUDE WATER?
D. L.
Bish, J. W. Carey, C. Fialips, Mineralogy & Geochemistry, Los Alamos
National Laboratory, Mail Stop D469, Los
Alamos, NM 87545, b***@lanl.gov
Lunar and Planetary Science XXXIV (2003) 1786.pdf
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1786.pdf
CAN HYDROUS MINERALS ACCOUNT FOR THE OBSERVED MID-LATITUDE WATER ON
MARS?
D. L. Bish1,2, D. T. Vaniman2, C. Fialips2, J. W. Carey2, W. C.
Feldman2, 1Dept. of Geol. Sciences, Indiana University,
Bloomington, IN 47405, b***@indiana.edu; 2Los Alamos National Lab, MS
D469, Los Alamos, NM 87545.
Sixth International Conference on Mars (2003) 3066.pdf
http://www.lpi.usra.edu/meetings/sixthmars2003/pdf/3066.pdf
PROPERTIES OF POTENTIAL MARTIAN MINERALS UNDER SIMULATED SURFACE
CONDITIONS.
D. L. Bish1, D. T. Vaniman1, S. J. Chipera1, and J. W. Carey1,
1Hydrology, Geochemistry, and Geology, Los Alamos National Laboratory,
MS D469, Los Alamos, NM 87545 b***@lanl.gov.
Lunar and Planetary Science XXXIII (2002) 1895.pdf
"A better knowledge of Martian hydrous mineralogy,
measured under conditions representative of the
Martian surface, can provide answers to key questions
such as: (1) Can water deposits formed during early
Martian hydrologic cycles survive for time spans on the
order of hundreds of millions of years over which life
would form; (2) What is the difference in water retention
between polar and equatorial regoliths, and how
would these differences influence a search of Mars for
evidence of life; (3) What are the relationships between
permafrost and hydrous solids on Mars; and (4) Can
hydrous-mineral deposits in a brackish regolith provide
a water resource for human exploration and development of Mars?"
http://www.lpi.usra.edu/meetings/lpsc2002/pdf/1895.pdf
A key question to answer is if this water when released from the
clays could remain as liquid water diurnally and/or seasonally at low
elevation sites.
In the latest Odyssey GRS reports, there is a definite difference in
the readings for the near equatorial area at about 15 degrees N lat.
and 15 degrees E long. for Winter compared to Summer as indicated by
the image in the MSNBC article:
Mars probes find more frozen water.
Northern ice boosts search for ancient life.
"Two false-color images show epithermal neutron flux during winter
(left) and summer (right) in Mars' northern hemisphere. Dark blue
hints at the presence of water ice. The north pole is covered by
frozen carbon dioxide in winter, but a summer "thaw" reveals the
frozen water beneath."
http://www.msnbc.com/news/931744.asp?0cv=TA00
The image appears as Fig. 1 in the recent Science article by
Mitrafanov et.al.:
CO2 Snow Depth and Subsurface Water-Ice Abundance in the Northern
Hemisphere of Mars.
I. G. Mitrofanov, M. T. Zuber, M. L. Litvak, W. V. Boynton,
D. E. Smith, D. Drake, D. Hamara, A. S. Kozyrev, A. B. Sanin, C.
Shinohara, R. S. Saunders, V. Tretyakov
SCIENCE,VOL 300, 27 JUNE 2003, p. 2081-2084
http://www-geodyn.mit.edu/hend.mola.pdf
This seasonal difference for this area is even more clear in a report
given at The 36th Vernadsky/Brown Microsymposium on Comparative
Planetology by Litvak et.al.:
Microsymposium 36, MS063, 2002
SEASONAL VARIATIONS OF SUBSURFACE HYDROGEN AS SEEN BY HIGH ENERGY
NEUTRON DETECTOR, MARS ODISSEY.
M. L. Litvak, I. G. Mitrofanov, A.S. Kozyrev, A.B. Sanin, W. Boynton,
C. Shinohara, D. Hamara, R. S. Saunders.
http://www.planetary.brown.edu/planetary/documents/Micro_36/Abstracts/063_Litvak_etal.pdf
Figure 1 in this report shows the variations in this near equatorial
region for 4 seasons.
I think therefore it would be useful to search for *seasonal*
differences in the high-resolution MOC images in this area.
Also very interesting are the fast neutron maps showing some areas
with moderately high hydrogen amounts. The fast neutron measurements
are most allied with the near surface hydrogen amounts, within a few
centimeters.
See the maps of fast neutrons in these reports:
ATMOSPHERIC CORRECTIONS FOR NEUTRONS REVEAL VARIATIONS IN SURFACE
COMPOSITION IN THE THARSIS REGION.
T. H. Prettyman, W. C. Feldman, W. V. Boynton, G. W.
McKinney, D. J. Lawrence, and M. T. Mellon.
Lunar and Planetary Science XXXIV (2003)
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1950.pdf
Microsymposium 36, MS070, 2002
FIRST RESULTS OF MARS MAPPING OF NEUTRON FLUX BY HIGH ENERGY NEUTRON
DETECTOR, MARS ODISSEY.
I. G. Mitrofanov, M.L. Litvak, A.S. Kozyrev, A.B. Sanin, W. Boynton,
C. Shinohara, D. Hamara, R. S. Saunders.
http://www.planetary.brown.edu/planetary/documents/Micro_36/Abstracts/070_Mitrofanov_%20etal.pdf
These images though don't give the seasonal differences for this close
surface water so you can't tell if there is a seasonal and/or diurnal
variation, which would indicate free water quite close to the surface
near the equator.
In Fig.1 of this first report, there is a strip of dark blue
indicating significant amounts of hydrogen at around -10 to -20 S.
lat. and -165 E long. There are also scattered, small light blue areas
indicating moderate amounts of hydrogen.
These would also be good places to search for seasonal changes in the
MOC images.
I found an interesting image in one of these areas:
Finely-dissected terrain in Memnonia/Sirenum region.
http://ida.wr.usgs.gov/html/m08025/m0802500.html
I had previously been interested in the Memnonia region because it
shows indications of surface fogs that I thought might indicate near
surface water in the near equatorial region:
"Early Morning Surface Fog. The presence of morning fogs in some
crater and channel bottoms is a Viking discovery with possible
implications for the future biological exploration of Mars. These
early morning views of the Memnonia region were taken one-half hour
apart using a violet filter to enhance the contrast of the
condensates. The areas marked by arrows are noticeably brighter in the
later picture. The fogs indicate specific spots where water is
exchanged, probably on a daily cycle, between the surface and the
atmosphere. The surface and lower air layers in this region become
unusually cold at night because of the thermal properties of the
surface. When the surface warms in the morning, it seems that a small
amount of water vapor-estimated to be about one-millionth of a meter
thick if liquefied is driven off; this vapor recondenses in the
atmosphere, which warms more slowly, to form a ground fog of ice
particles. [P17487; 13°S,147° W]"
http://history.nasa.gov/SP-441/ch12.htm
cf.:
From: Robert Clark (rgrego...@yahoo.com)
Subject: Re: And now the weather ... on Mars! (Forwarded)
Newsgroups: sci.astro, alt.sci.planetary, sci.geo.meteorology
Date: 2002-07-03 17:34:57 PST
http://groups.google.com/groups?&selm=832ea96d.0207031634.1821e37f%40posting.google.com
Bob Clark
______________________________________________________________________________
Double-A
[snip]
[snip]
>
> Bob Clark
Whether water is available, or has been available on Mars, the low
atmospheric oxygen content of 0.13% is not a promising indicator that
life has ever been there.
Double-A
Bigdakine
>Mars.
>From: doub...@hush.com (Double-A)
>Date: 7/19/03 10:59 AM Hawaiian Standard Time
>Message-id: <79094630.03071...@posting.google.com>
Perhaps that is a hasty asessment. Life, as far as we know, doesn't require
Oxygen. In fact, Oxygen may prevent life from starting in the first place.
On terra firma, we have sulfur-reducing bacteria, which derive energy from
reducing sulfur compounds. No Oxygen required they. Further, the fruits of
their labors do not include free oxygen either, but H2S. Perhaps a lack of free
O2 and Sulfur compounds would not bode well. But the finding of Sulfides in the
famed meteorite ALH84001 formed part of the evidence that led some researchers
to conclude that Mars did have life.
On the other hand, Mars may have had a much thicker atmosphere at one point,
with a higher concentration of O2.
As to whether there is or was life on Mars probably won't be decided until
there is a thorough investigation of the planet.
In the mean time, I'll be looking at Mars as it nears opposition on August 27.
Folks, this is the closest approach Mars will have made to Earth in over 60,000
years. Pray for clear skies.
Stuart
Dr. Stuart A. Weinstein
Ewa Beach Institute of Tectonics
"To err is human, but to really foul things up
requires a creationist"
George
"Bigdakine" <bigd...@aol.comGetaGrip> wrote in message
news:20030719172959...@mb-m24.aol.com...
Amen to that. I just bought some new lenses for my telescope and am looking
forward to trying them out on Mars this month and next.
Alexander Duerloo
atmospheric structure were not what they are now. There is evidence that
Mars had an earthlike atmosphere and climate (rather chilly).
Rich
In infinite wisdom Alexander Duerloo answered:
> There hasn't always been only 0.13% of oxygen. The planet's climate and
> atmospheric structure were not what they are now. There is evidence that
> Mars had an earthlike atmosphere and climate (rather chilly).
Actually, from what I've seen the evidence for water (or at
least some liquid) on the Martian surface in the past looks pretty
good.
But I'm not aware of the evidence for the composition of the
early Martian atmosphere. Where did this information come from?
Rich
Robert Clark
______________________________________________________________
exoscientist
(B)
07/22/03 04:30 AM
Re: Hydrous Minerals at Mid-latitudes of Mars [re: exoscientist]
This report to be given at the September meeting of the Planetary
division of the AAS argues it may be ice instead of clays responsible
for the high water readings at some near equatorial sites:
DPS 35th Meeting, 1-6 September 2003
Session 9. Mars Surface I
Oral, Chairs: E. R. Kraal and R. C. Quinn, Wednesday, September 3,
2003, 10:30am-12:00noon, DeAnza III
--------------------------------------------------------------------------------
[9.03] Mars Low-Latitude Neutron Distribution: Possible Remnant
Near-Surface Water Ice
B.M. Jakosky, M.T. Mellon, S. Varnes (Univ. of Colorado), W. Feldman
(LANL), W. Boynton (Univ. of Arizona), R.M. Haberle (NASA/Ames)
The Mars Odyssey GRS/NS has provided indications of near-surface water
in the equatorial and mid-latitudes, in amounts typically from 5-10 %
and ranging up to 15-20 %. Although such high abundances could be
present as adsorbed water in clays, other measurements suggest that
clays are not present. The spatial pattern of where the water is
located is not consistent with a dependence on composition (as would
be the case if it were related to clay), topography, present
atmospheric water abundance, latitude, or thermophysical properties.
The "wave-number two" pattern of water abundance is very reminiscent
of something related to an atmospheric phenomenon. We suggest that the
high water abundances could be due to transient ground ice that is
present in the top meter of the surface. Ice would be stable at
tens-of-centimeters depth at these latitudes if the atmospheric water
abundance were about twice the present value, much as ice is stable
poleward of about 60 degrees latitude for current water abundances.
Higher atmospheric water abundances could result under present-day
orbital conditions if the south-polar cap were to lose its annual
covering of CO2 ice; this would expose an underlying water-ice cap
that could supply water to the atmosphere during southern summer. If
this hypothesis is correct, then (i) the water ice is unstable today
and is in the process of sublimating and diffusing back into the
atmosphere, and (ii) the current configuration of perennial CO2 on the
south and not the north might not be representative of the present
epoch over the last ten thousand years.
--------------------------------------------------------------------------------
http://www.aas.org/publications/baas/v35n4/dps2003/52.htm
This also raises the possibility that liquid water could exist there
near surface seasonally.
Note if this water is subsurface then just the overpressure of the
soil may be enough for the water to remain in liquid form. Then it
would not have to be in low elevation sites.
cf:
exoscientist
07/13/03 10:50 AM
Re: Dark Slope Streaks [re: borman]
http://uplink.space.com/showthreaded.php?Cat=&Board=sciastro&Number=526172
Bob Clark
______________________________________________________________
rgrego...@yahoo.com (Robert Clark) wrote in message news:<832ea96d.03071...@posting.google.com>...
> The post copied below was posted to the Space.com board
> uplink.space.com in regards to a new paper that suggests clays may
> explain the high levels of water detected by Mars Odyssey in some near
> equatorial regions on Mars:
>
> Stability of hydrous minerals on the martian surface.
> David L. Bish, J. William Carey, David T. Vaniman and Steve J. Chipera
> Los Alamos National Laboratory, Mail Stop D469, Los Alamos, NM 87545,
> USA
> Icarus, Volume 164, Issue 1, July 2003, Pages 96-103.
> http://dx.doi.org/10.1016/S0019-1035(03)00140-4
>
> A similar theory is proposed by Tetsuya Tokano:
>
> Spatial inhomogeneity of the martian subsurface water distribution:
> implication from a global water cycle model.
> Tetsuya Tokano
> DLR??Institut für Raumsimulation, 51170, Köln, Germany
Lucius Chiaraviglio
>Whether water is available, or has been available on Mars, the low
>atmospheric oxygen content of 0.13% is not a promising indicator that
>life has ever been there.
By far not all life requires or produces molecular oxygen. You can
find whole ecosystems on Earth that operate with no molecular oxygen. And
even if Mars has oxygenic photosynthetic organisms, the low duty cycle in
which they could be active (due to low duty cycle of water availability) would
severely limit the amount of oxygen they could produce (and keep in mind that
splitting water to produce hydrogen and oxygen would drive down the amount of
water, thus decreasing the biological duty cycle). Water availability would
not impose as strict a limit on the abiotic reaction of oxygen with various
materials (including organic matter left over from life forms), so low water
availability would tend to favor low steady-state oxygen concentrations. Of
course, the small measured concentration of oxygen in Mars' atmosphere does
not prove the existence of oxygenic photosynthetic life, either -- until we
get a better handle on the surface composition of larger areas of Mars, for
all we know the oxygen could be produced entirely by photodecomposition of
water and carbon dioxide.
--
Lucius Chiaraviglio
Approximate E-mail address: luci...@chapter.net
To get the exact address: ^^^ ^replace this with 'r'
|||
replace this with single digit meaning the same thing
(Spambots of Doom, take that!).
Robert Clark
Here's another map of fast neutrons, which are most allied with
hydrogen in the topmost layer of soil:
VERTICAL DISTRIBUTION OF SHALLOW WATER IN THE DISTINGUISHABLE REGIONS
AT LOW
AND HIGH LATITUDES OF MARS: NEUTRON DATA DECONVOLUTION OF HEND.
I.G. Mitrofanov, M.L. Litvak, A.S. Kozyrev, A.B. Sanin1, V. Tretyakov,
W.V. Boynton, D.K. Hamara, C. Shinohara2, R. S. Saunders, D. Drake, R.
Kuzmin
http://www.lpi.usra.edu/meetings/sixthmars2003/pdf/3080.pdf
See Fig. 2 here. This does not give the seasonal difference in the
fast neutron amounts so you can't tell if this is free water or
chemically bound water.
However, there are a few scattered areas of light blue to dark blue
in the near equatorial region indicating moderate to significant
amounts of water in some form in those locations.
One particular area of dark blue is located slightly west of 120
degrees E long. and slightly south of 0 degrees lat. Anyone from the
HEND data able to better constain the coordinates of this site?
Here's a map of MOC images covering this general area:
Area between -15°and 0° Latitude and 240°and 255° Longitude
http://ida.wr.usgs.gov/html/areasg/c_07s247.htm
Here's one image from this area:
Transition between deep and shallow portions of valley.
http://ida.wr.usgs.gov/html/e13022/e1302254.html
Note that there are whitish deposits in the lower elevation regions
in the image, in the craters and channels.
In one of the craters there is the definite appearance that this
white material flowed down the sides to the bottom of the crater:
http://ida.wr.usgs.gov/fullres/divided/e13022/e1302254a.jpg
Bob Clark