WATER ON MARS
MAINSTREAM MARTIAN WATER & GEOLOGICAL DATA
08 Nov 2000  Harry Mason

MOC Image Tests of the Mars Ocean Hypothesis MGS MOC Releases
MOC2-180 to MOC2-183, 1 October 1999 

Asking questions and testing hypotheses is central to scientific investigation. One idea about Mars that emerged in the middle 1980s as people were investigating Viking orbiter images (obtained 1976-1980) is the "Mars ocean hypothesis". Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images obtained during the spacecraft's first year in orbit have recently been used to test this hypothesis. Pictures presented by clicking on the icons below show what MOC has found in areas proposed to have been ancient coastal environments on Mars.

The ocean hypothesis envisions that the Martian northern lowlands were once covered by either a single, continuous body of water or incompletely covered by a series of smaller seas connected by spillways. The ocean hypothesis is very important, because the existence of large bodies of liquid water in the Martian past would have a tremendous impact on ancient Martian climate and might also have implications for the search for evidence of past life on the planet.

Prior to the ocean hypothesis, most of the data gathered in the 1960s and 1970s seemed to suggest that Mars had a very dry past, not a wet one. Understanding how much water was once present on the red planet is critical to unraveling the planet's entire history.

Scientists usually present their observations, conclusions, and new hypotheses in papers that are written for scientific journals. These articles are commonly subjected to a process known as "peer review". Before an article describing a body of research is published, the journal editor sends it out to several other scientists who are usually experts on the subject of the paper. These scientists review the paper, examine it for flaws and/or provide suggestions for improving the work and its presentation.

If the reviewers raise significant questions or indicate that revisions to the paper are necessary, then the editor returns it to the author for improvement and clarification. Sometimes, after the paper is revised, the editor might send it out for an additional review. Eventually (unless the paper is rejected), the editor is satisfied that the author has presented the work well and that the paper represents an important advance in its scientific field, and the paper is published.

One of the key elements of the Mars ocean hypothesis has been the identification and publication of possible shorelines around the margins of the Martian northern plains. Only a few papers have been published in peer-reviewed journals that provide maps and figures that describe the proposed ancient coastlines of Mars.

During the Aerobraking and Science Phasing Orbits portion of the MGS mission (September 1997 to September 1998), the MOC science team devoted about 2% of its observations to taking images of the proposed and previously published shorelines. Looking for ancient shorelines is not easy.

On Earth, it is often difficult to identify the coast of an ancient lake, sea, or ocean using high resolution satellite or aerial photographs. Ancient shorelines may be discontinuous because they have been modified after the body of water disappeared (e.g., they can be covered by lava or sand dunes), or may be difficult to see because of either very steep or very shallow topography. People who map ancient shorelines on Earth find that it is very important to visit the site in person to confirm any suspected shoreline seen in a photograph.

Often, what makes a shoreline appear in a photo is a variation in vegetation that results from the way plants grow in soils of different permeability and porosity--both of which can be a function of the size of sediment grains and compaction of the sediment along an ancient coastline. Obviously, on Mars the problem of identifying ancient coastlines is hindered by the lack of vegetation and the fact that people presently cannot visit the planet and check the landforms in person.

Despite the difficulties of finding and confirming the presence of ancient shorelines in aerial and satellite pictures, MGS MOC images of places that were already proposed--on the basis of Viking orbiter images--to be ancient coastlines were examined and the results of that examination described in a paper recently published in the American Geophysical Union's journal, Geophysical Research Letters.

The figures and captions presented here describe and elaborate upon results presented in this paper, titled, "Oceans or Seas in the Martian Northern Lowlands: High Resolution Imaging Tests of Proposed Coastlines," by MOC scientists Michael C. Malin and Kenneth S. Edgett.

Prior to the identification of possible shorelines in the mid-1980s, no evidence had been found to stimulate the idea that Mars once had seas or oceans. Rare discussions of large bodies of water on Mars were considered highly speculative at best. The purported shorelines changed this: if shorelines existed on Mars, then bodies of water must have once existed to form these features. One would think that the converse must also be true: if the shorelines did not exist, then the "evidence" used to suggest that Mars had seas or oceans did not exist, and thus the idea that such seas or oceans once existed could be forgotten.

However, once a speculative interpretation is proposed, it is often very difficult to subsequently prove that the thing proposed doesn't exist (a process called "proving the negative").

The MGS MOC images from 1997 and 1998 do not show any obvious or unambiguous coastal landforms where previous researchers--working with lower spatial-resolution Viking images--indicated that shorelines might occur. If these peer-reviewed and published shorelines never existed, then the oceans and seas that were proposed to have created the putative shorelines also never existed.

But once proposed, it is not possible to disprove such ideas with any certainty. Thus, the idea that Mars at one time had seas or oceans cannot not be ruled out, but the basis for the 1980s "ocean hypothesis" appears to have been incorrect.

Thus, these new MOC results can not be viewed as anything more than a contribution to the on-going study of Mars

and the nature of its ancient past, albeit one that challenges some popular views. For additional information, click on the icons below to see pictures that illustrate the MGS MOC results. Also read the Malin Space Science Systems PRESS RELEASE on the same subject.   

REFERENCES: Papers Regarding Past Oceans and Seas on Mars October 1999
Check your nearest university library for these: 

1986: 
.. "Sedimentary deposits in the northern lowland plains, Mars," by B.K. Lucchitta, H.M. Ferguson, and C. Summers, Journal of Geophysical Research, supplement, v. 91, p. E166-E174, 1986. 1989: 

.. "Transitional morphology in west Deuteronilus Mensae, Mars: Implications for modification of the lowland/upland boundary," by T.J. Parker, R.S. Saunders, and D.M. Schneeberger, Icarus, v. 82, p. 111-145, 1989. 1991: 

.. "Ancient oceans, ice sheets, and the hydrological cycle on Mars," by V.R. Baker, R.G. Strom, V.C. Gulick, J.S. Kargel, G. Komatsu, and V.S. Kale, Nature, v. 352, p. 589-594, 1991. b.. "Mars Elysium Basin: Geologic/volumetric analyses of a young lake and exobiologic implications," by D.H. Scott and M.G. Chapman, Proceedings of Lunar and Planetary Science, v. 21, p. 669-677, 1991. 1992:  

.. "New evidence of lacustrine basins on Mars: Amazonis and Utopia Planitae," by D.H. Scott, M.G. Chapman, J.W. Rice, Jr., and J. M. Dohm, Proceedings of Lunar and Planetary Science, v. 22, p. 53-62, 1992. 1993: 

.. "Coastal geomorphology of the Martian northern plains," by T.J. Parker, D.S. Gorsline, R.S. Saunders, D.C. Pieri, and D.M. Schneeberger, Journal of Geophysical Research, v. 98, p. 11061-11078, 1993. 1995: 

.. "Map of Mars showing channels and possible paleolake basins," by D.H. Scott, J.M. Dohm, and J.W. Rice, Jr., scale 1:30,000,000, U.S. Geological Survey Miscellaneous Investigations Series, Map I-2561, 1995. 1997: 

.. "Water on early Mars: Possible subaqueous sedimentary deposits covering ancient cratered terrain in western Arabia and Sinus Meridiani," by K.S. Edgett and T.J. Parker, Geophysical Research Letters, v. 24, p. 2897-2900, 1997. 1998: 

.. "Oceans in the past history of Mars: Tests for their presence using Mars Orbiter Laser Altimeter (MOLA) data," by J.W. Head III, M. Kreslavsky, H. Hiesinger, M. Ivanov, D.E. Smith, and M.T. Zuber, Geophysical Research Letters, v. 24, p. 4401-4404, 1998. 1999: 

.. "Oceans or seas in the Martian northern lowlands: High resolution imaging tests of proposed coastlines," by M.C. Malin and K.S. Edgett, Geophysical Research Letters, v. 26, p. 3049-3052, 1999.

MALIN SPACE SCIENCE SYSTEMS, INC. SAN DIEGO, CA 92191-0148 TELEPHONE: (858) 552-2650, EXT. 500 http://www.msss.com/ 
Contact: Michael Ravine,
http://www.msss.com/press_releases/shorelines/index.html 

RELEASE 1 OCTOBER 1999 HIGH-RESOLUTION IMAGES SHOW NO EVIDENCE OF ANCIENT OCEANS ON MARS 

Scientists at Malin Space Science Systems (MSSS) of San Diego, CA, have used high resolution images of Mars taken with the Mars Orbiter Camera (MOC) on Mars Global Surveyor to test the hypothesis that oceans once covered much of the northern hemisphere of Mars. The possibility that such a body of water once existed was suggested by features in Viking images that were interpreted by a number of researchers as remnants of ancient coastlines.

During 1998, MSSS scientists Michael Malin and Kenneth Edgett targeted about 2% of the MOC images in places that would test shorelines proposed by others in the scientific literature. The MOC images have a resolution five to ten times better than Viking provided. With this closer inspection, none of these features appears to have been formed by the action of water in a coastal environment.

Their analysis was published this week in Geophysical Research Letters, in a paper entitled, "Oceans or Seas in the Martian Northern Lowlands: High Resolution Imaging Tests of Proposed Coastlines." 

"The ocean hypothesis is very important, because the existence of large bodies of liquid water in the Martian past would have had a tremendous impact on ancient Martian climate and implications for the search for evidence of past life on the planet," said Dr. Edgett, a staff scientist at MSSS. "The MOC images we took last year do not show any coastal landforms in areas where previous researchers--working with lower resolution Viking images--proposed there were shorelines." 

As presented in the Geophysical Research Letters paper, the analysis focused on four different areas that had been proposed as coastlines. One of these areas is northwest of the great volcano, Olympus Mons (see inset at lower right of Figure 1).

Viking images of the linear feature separating the western margin of the Lycus Sulci from the lower elevation smoother Amazonis plains (upper left in Figure 1) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. 

moc2_msss_sh_aur_cntx_100.gifmoc2_msss_sh_aur_cntx_100.gif 

Figure 1. The Amazonis/Lycus Sulci Contact. This Viking image taken in the late 1970s shows the location of a proposed shoreline. The three small white boxes show the locations of the MOC images targeted on the feature in 1998. The inset at the lower right is a Viking image showing the location of the proposed shoreline with respect to Olympus Mons (click on image for higher resolution view). Figure credit: NASA/JPL/Malin Space Science Systems. 

[I suggest the Skywatch viwer visit the URL  http://www.msss.com/press_releases/shorelines/index.html  
to see these figures - H. Mason] 

Three MOC images were acquired along this proposed shoreline, covering the areas indicated by the white boxes in Figure 1. Each image was targeted to straddle the feature, a rise that runs diagonally across the scene from near the lower left toward the upper right. The middle section of the central image (SPO2-428/03), shown in Figure 2, was taken in July 1998. The Lycus Sulci uplands (lower half) here are roughly-textured while the flat Amazonis plains (upper half) appear more smooth. This image shows that the contact between Amazonis and Lycus Sulci is clearly not a wave-cut cliff, and that there are no features that can be unambiguously identified as coastal landforms.   

moc2_msss_sh42803_100.gifmoc2_msss_sh42803_100.gif   

Figure 2. MOC Image SPO2-428/03, providing a close-up view of the proposed shoreline in Figure 1. The picture has a resolution of 15 ft and covers an area about 3 miles across. It is illuminated from the right (click on image for higher resolution view). Figure credit: NASA/JPL/Malin Space Science Systems.   

[I strongly suggest the Skywatch viewer visit the URL  http://www.msss.com/press_releases/shorelines/index.html 
to see these images - H. Mason]  

"Even on Earth, looking for ancient shorelines from the air or space is a challenge," said Dr. Malin. "But, despite the difficulties in identifying ancient coastlines remotely, we believe these MOC images of the proposed shorelines are of a high enough resolution that they would have shown features indicative of a coastal environment had there been an ancient ocean on Mars." 

While the suggestion that Mars at one time had oceans cannot not be ruled out, the foundation for the "ocean hypothesis" developed in the 1980s on the basis of suspected shorelines appears now to have been incorrect. However, it should be understood that there is significant other evidence of water on Mars in the past, both from Mars Global Surveyor and from previous missions. Today, the MOC continues to acquire new high resolution pictures, each one helping to search for clues to the very important question of the role of water in the evolution of Mars. 

Additional details and more images from the Malin and Edgett paper can be found at:  http://www.msss.com/mars_images/moc/grl_99_shorelines/  

H. Mason Comment :- 
NB. I personally disagree with the (MOC) Malin Group interpretation of these images. If you take the USGS Mars Digital Elevation Data and these new Malin images and the copious volcanic lava flows plus dust storm sediment deposition that has probably occurred since any sea "existed" then the resultant coast line image features are quite reasonable ........ 

On Earth it IS VERY difficult to detect old coast lines of just a few million years age. There is one such coastline in Southern Australia (WA-SA border region) along the northern edge of the Eucla Basin (Nullarbor Plain) where Tertiary age seas lapped onto the older Palaeozoic-Proterozoic age basement of the Officer Basin. 

There are coastal heavy mineral sand deposits buried along an old strand line there. These mark the edge of the ~50 Million Year old Tertiary age Carbonate deposits that deepen southwards to the then open sea. This ancient coastal geology is partly masked by younger windblown sand and regolith weathering and requires shallow drilling and very close observation insitu to determine the coastal geo-history. The 20 meter resolution TM Satellite Imagery and ~270 meter pixel resolution DEM coverage of the Eucla Basin area closely resemble the Martian "coast" line imagery in many respects. 

There is a raised dune cum strand line visible on the higher definition Australian DEM imagery, together with a very large ancient dendritic river system that until recently flowed from the Australian Interior southwards into the then Eucla Basin sea. The raised strand line and beach dune system is poorly visible on the 20 meter pixel resolution TM satellite imagery. 

No such strand line or coast parallel dune system is visible on the Martian 1ooo meter DEM or the latest detailed Malin Mars satellite imagery - as shown by the Malin group..... It actually looks like the plain is higher than the adjacent foothills to the Olympus Mons volcano complex. Thus implying no ancient sea coast exists - as per their "findings". But note that their detailed images are reversed with craters showing as small bumps rather than hollows - you must invert the detailed image figure #2 to see the true picture ..... 

You be the judge of if these features represent something like an ancient sea or large lake bed coast line. It certainly still looks so to me - Malin Group research findings - or not !!! 

Further if we look at the ~ 75 million year old Cretaceous age section of the Canning Basin in northern Western Australia - which also edges out onto the same Proterozoic basement as the younger Tertiary age Eucla Basin further south - one can see that the Cretaceous sea edge of the Canning Basin has no strand line or dune edges visible - in the field, or on DEM, or on satellite imagery. 

In all probability it's Cretaceous sea coast of strand lines and linear dune fields has been removed by younger weathering and obliterated by younger high speed winds which have covered the entire Canning Basin in very young ribbon dunes and sheeted sand deposits. Such winds did NOT cover the Eucla in extensive ribbon dunes. There are a few dunes and some sheeted sand deposits - but nothing to compare to the Canning Basin coverage. 

The inference is that the high winds and palaeo rain fall helped strip away or cover the strand line edges to the older ~75 million year Cretaceous Canning Basin seas. This has not happened to the ~50 million year Eucla Basin sea strand lines. However even the Eucla strand lines are difficult to detect on satellite imagery and show up more readily on the DEM image - especially so when the DEM data is number crunched to show the first derivative rate of change of elevation. 

The Canning Basin Cretaceous sea does NOT show up as a depressed flat plain on DEM imagery. It has been raised and dissected due to minor tectonic activity and can not NOW be detected by such a DEM method. It looks very similar in surface pattern to the adjacent Proterozoic terrain. It does not show up on satellite imagery either. We only know it was there from field observation of the rocks and mark one eyeball geological mapping. 

The point being that DEM data allows you to search for very young undisturbed seas and coast lines, but not necessarily for older ones; whilst satellite imagery is a very unreliable method in the search for either young or older seas and coast lines - especially where tectonic action and subsequent weathering have obliterated the features being sought. 

I believe therefore that any seas visible on Martian DEM data are liable to be fairly young (assuming that Martian erosional rates are similar to Earth's - not necessarily so !!). 

The Malin Group stated that: "The MGS MOC images from 1997 and 1998 do not show any obvious or unambiguous coastal landforms where previous researchers--working with lower spatial-resolution Viking images--indicated that shorelines might occur."  Well you would be very hard put to meet these conditions on Earth where we "KNOW" where our ancient seas were ................. 

One oddity of Malin's site is that downloads of the close up detailed image of figure # 2 are reversed such that the craters become bumps instead of holes and the shore and "on-shore" sea coastal topography looks lower than the flat plain of the possible former sea. Was this done to mislead the viewer ??? Load the image into your own image software and invert it to see it as it should be viewed - then the sea looks very real !!! 

Taken with the recent USGS statements re olivine detection and "thus" a dry-cold Mars throughout her geo-history, one wonders if we are now meant to believe that Mars has no water and never had - I wonder why this shift in science viewpoint (and possible attempts at deception ?) has occurred ??? 

Although the evidence is NOT totally conclusive it certainly looks as if Mars has had large amounts of water and continues to have limited amounts of water. 

Lets go there and find out for sure !!! 
H. Mason 

A Global View of Martian Surface Compositions from MGS-TES Joshua L. Bandfield, * Victoria E. Hamilton, Philip R. Christensen 

Thermal Emission Spectrometer (TES) data from the Mars Global Surveyor (MGS) are used to determine compositions and distributions of Martian low-albedo regions. Two surface spectral signatures are identified from low-albedo regions. Comparisons with spectra of terrestrial rock samples and deconvolution results indicate that the two compositions are a basaltic composition dominated by plagioclase feldspar and clinopyroxene and an andesitic composition dominated by plagioclase feldspar and volcanic glass. The distribution of the two compositions is split roughly along the planetary dichotomy. The basaltic composition is confined to older surfaces, and the more silicic composition is concentrated in the younger northern plains. 

Department of Geology, Arizona State University, Tempe, AZ 85287-1404, USA.  To whom correspondence should be addressed. E-mail:

Lunar Impact History from 40Ar/39Ar Dating of Glass Spherules 
Timothy S. Culler, 13* Timothy A. Becker, 4* Richard A. Muller, 23* Paul R. Renne 14* 

Lunar spherules are small glass beads that are formed mainly as a result of small impacts on the lunar surface; the ages of these impacts can be determined by the 40Ar/39Ar isochron technique. Here, 155 spherules separated from 1 gram of Apollo 14 soil were analyzed using this technique. The data show that over the last ~3.5 billion years, the cratering rate decreased by a factor of 2 to 3 to a low about 500 to 600 million years ago, then increased by a factor of 3.7 ± 1.2 in the last 400 million years. This latter period coincided with rapid biotic evolutionary radiation on Earth. 

1 Department of Geology and Geophysics,

2 Department of Physics, University of California, Berkeley, CA 94720, USA.

3 Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

4 Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, USA. *

These authors are listed alphabetically. 

To whom correspondence should be addressed. E-mail:

Internal Structure and Early Thermal Evolution of Mars from Mars Global Surveyor Topography and Gravity 
Maria T. Zuber, 14* Sean C. Solomon, 2 Roger J. Phillips, 3 David E. Smith, 4 G. Leonard Tyler, 5 Oded Aharonson, 1 Georges Balmino, 6 W. Bruce Banerdt, 7 James W. Head, 8 Catherine L. Johnson, 2 Frank G. Lemoine, 4 Patrick J. McGovern, 2 Gregory A. Neumann, 14 David D. Rowlands, 4 Shijie Zhong 1 

Topography and gravity measured by the Mars Global Surveyor have enabled determination of the global crust and upper mantle structure of Mars. The planet displays two distinct crustal zones that do not correlate globally with the geologic dichotomy: a region of crust that thins progressively from south to north and encompasses much of the southern highlands and Tharsis province and a region of approximately uniform crustal thickness that includes the northern lowlands and Arabia Terra. The strength of the lithosphere beneath the ancient southern highlands suggests that the northern hemisphere was a locus of high heat flow early in Martian history. The thickness of the elastic lithosphere increases with time of loading in the northern plains and Tharsis. The northern lowlands contain structures interpreted as large buried channels that are consistent with northward transport of water and sediment to the lowlands before the end of northern hemisphere resurfacing. 

1 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

2 Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA.

3 Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA.

4 Earth Sciences Directorate, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA.

5 Center for Radio Astronomy, Stanford University, Stanford, CA 94035-9515, USA.

6 Groupe de Recherches de Geodesie Spatiale, Toulouse, France.

7 Jet Propulsion Laboratory, Pasadena, CA 91109, USA.

8 Department of Geological Sciences, Brown University, Providence, RI 02912, USA.

* To whom correspondence should be addressed. E-mail:
Present address: Lunar and Planetary Institute, Houston, TX 77058. USA. 

Related articles in Science:

PLANETARY SCIENCE: Buried Channels May Have Fed Mars Ocean

NB. This could possibly be an image of a developing "dust devil" and not a water spout ??? [H. Mason] 

We are calling for the JPL to give some consideration to photographing the area of the water spout that Dr. Leonard Martin of Lowell Observatory published in 1980 in the NASA Activities (Dec. 1980, vol. 11, number 12). Then we are asking that this site be considered as the primary landing site for the upcoming Mars Pathfinder Mission Rover. There were two overlapping photos taken 4-1/2 seconds apart which clearly show this geyser eruption of water. This area is significant in establishing that water still exists on Mars. What this means is that if the area is percolating with hot water, two things are apparent: 

. 1. The peroxides that are present all over the surface of Mars would be vanquished from this wet area.

. 2. Any microbial life would thrive in this area. 

Like all of the work that we have done on the Cydonia region, Dr. Martin's work has never been seen or heard from again since 1980. When I went to Flagstaff, to the Lowell Observatory a few years ago, the attendants at the visitor's center informed me that Dr. Martin was still there, but none of them had ever heard of the water spout, and of course, the pictures were NOT on display. It seems like almost a conspiracy to cover-up any evidence that Mars could have or still contains the prime ingredients for life. What do you think? How do we get NASA to consider this area to put the lander on to do the soil sample analysis for life forms?? 

You may also wish to refer to my book (pps. 60-66) which gives the details and frame numbers of this discovery by Dr. Martin. 

Sincerely, 
Vince DiPietro

REPORT OF FINDINGS OF THE FACE ON MARS 
by Vince DiPietro 
DiPietro on Dr. Barthalamew Nagy 

A New Case for Liquid Water on Mars 
Published: 1998 July 23 3:25 pm ET (1925 UT) 

A father-son team of scientists, including one who worked on the Viking missions in the mid-1970s, believe that liquid water -- in limited amounts and for limited times -- can exist on present-day Mars. 

Dr. Gilbert Levin of Biospherics, Inc. and his son, Dr. Ron Levin of MIT's Lincoln Laboratory, presented their analysis, based on Viking and Mars Pathfinder data, July 20 at the annual meeting of the Society of Photo-Optical Instrumentation Engineers (SPIE) in San Diego. 

According to their research, a thin frost forms in some regions of the planet overnight, as the atmosphere cools and the trace amounts of water vapor freeze out. This frost was seen on a number of Viking images. As the Sun rises, the ground warms enough to melt the ice. 

The ice would not sublime directly to vapor and return to the atmosphere, the Levins conclude, because the atmosphere just a meter above the surface remains too cold to hold must water vapor. Data collected by Mars Pathfinder showed that temperatures a meter above the surface were often dozens of degrees colder that those at the surface. 

Since the atmosphere is too cold to hold the water as vapor and the ground is warm enough to melt the ice, the Levins conclude, the water must melt into a liquid. The liquid water would remain on the surface until the temperature of the atmosphere rises enough to allow the water to evaporate. 

The Levins believe that this liquid water would be enough to support the existence of microorganisms in the Martian soil. "Terrestrial experiments in natural environments, including the Death Valley sand dunes of California, demonstrated that the amount of soil water moisture predicted by the model is sufficient to sustain survival and growth of common soil icroorganisms," the elder Levin said. 

Gilbert Levin has been a long-time proponent of life on Mars. A scientist involved with the Viking missions in the mid-1970s, he believes data from the Labeled Release (LR) experiment on the Viking landers showed that primitive life does exist on present-day Mars. Most scientists believe the data from the experiment are inconclusive, and that the existence of strong ultraviolet radiation at the surface and highly oxidizing chemistry rules out life on the surface. 

"This model [for the formation of liquid water] removes the final constraint preventing acceptance of the biological interpretation of the Viking LR Mars data as having detected living microorganisms in the soil of Mars," Levin said. "It comes at a time when a growing body of evidence from the Earth and space are supporting the presence of life not only on Mars, but on many celestial bodies." 

Mars Water marswater.gif 

Water is the key to the most important scientific questions dealing with Mars.
a.. It is vital to the existence of life on that planet, past or present.
b.. Apparent fluvial erosion features constitute the most convincing evidence of dramatic climate change on Mars.
c.. The utilization of insitu water will be necessary for the successful human exploration of Mars. Based on spacecraft and Earth-based observations of Mars, we have a good understanding of the annual cycle of water vapor in the Martian atmosphere. The most important source of this water is the north residual polar cap from which large quantities of water vapor sublime during late spring and early summer. The apparent regularity of the cycle allows us to make a model prediction of today's atmospheric water vapor distribution on Mars. Note that the total amount of water in the atmosphere is very small (measured in precipitable micrometers). If all the water in the Martian atmosphere were to rain out at any given time, it would make a puddle less than a hundredth of a centimeter deep! Detailed computer modeling allows us to infer that there is another significant reachable reservoir of water on Mars, besides the polar caps and the atmosphere. Approximately 10 times the total atmospheric inventory of water can be found adsorbed in the top few centimeters of the Martian soil. This could represent an important resource and will be the object of future landed spacecraft missions.

Indications are that this adsorbed water supplies much of the atmospheric water vapor that exchanges between the hemispheres during the course of the Martian year. http://www-mgcm.arc.nasa.gov/  

PLANETARY NEWS with Simon Mansfield: 

Reseacher Suspects Liquid Water on Mars 

San Diego - September 1, 1998 - Dr. Gilbert V. Levin, Mars Viking Experimenter, claims that his studies reveal water exists on the Red Planet's surface in sufficient amounts to sustain microbial life. 

His findings were presented to the Annual Meeting of the Society of Photo-Optical Instrumentation Engineers (SPIE) in San Diego in early July. Dr. Levin, President of Biospherics in Beltsville, Maryland, shared authorship with his son, Dr. Ron Levin, physicist at the MIT Lincoln Laboratory in Boston. The importance of the study, Dr. Gilbert Levin said, is that it clinches the case that his Viking LR experiment found life on Mars in 1976, a conclusion that he announced in 1997. 

In recent years, all arguments against the LR experiment had been eliminated except the claim that there was no life-requiring liquid water on the surface of the Red Planet. Last February, in discussing Mars against the background of startling new findings of life in hostile Earth environments, Dr. Wesley Huntress, NASA's Associate Administrator for Space Science, said: "We used to think that life was fragile, but wherever liquid water and chemical energy are found, there is life. There is no exception. Life may be a cosmic imperative." 

Dr. Levin described a dynamic daily cycle on Mars in which the extreme cold of the Martian atmosphere greatly restricts its ability to hold water vapor. Thus, the scant water vapor on Mars is forced down to the surface, where it is deposited in frozen form. As the sun rises, the ice melts, but its evaporation is restricted by the low vapor capacity of the overlying cold atmosphere. Levin cited Pathfinder's results to show that the atmosphere immediately above the surface warms considerably, equaling a spring day on Earth, but, just a couple of feet above the surface, temperatures are sub-freezing. The warmed surface layer of air absorbs water vapor until saturated. No more water can then evaporate from the surface, and the ice remaining there melts into liquid water. As the sun mounts, the temperature of the atmosphere above the surface warms sufficiently to permit any remaining water and ice to evaporate. However, during this daily cycle, the soil has been moistened with enough water to sustain microorganisms. 

Dr. Levin explained: "Based on Viking and Pathfinder data, and consistent with the principles of thermodynamics of the triple point of water, a model has been created for a diurnal water cycle on Mars. The model predicts the presence of several tenths of a percent to one percent water moisture in the topmost layer of the surface material over large regions of Mars.

Images taken by the Viking Lander cameras show nightly deposits of surface water frost, even snow, verifying the prediction of the model. Terrestrial experiments in natural environments, including the Death Valley sand dunes of California, demonstrated that the amount of soil water moisture predicted by the model is sufficient to sustain survival and growth of common soil microorganisms." Levin states: "This model removes the final constraint preventing acceptance of the biological interpretation of the Viking LR Mars data as having detected living microorganisms in the soil of Mars. It comes at a time when a growing body of evidence from the Earth and space are supporting the presence of life not only on Mars, but on many celestial bodies." As a result, Levin pressed for early Mars biology missions, none of which is currently planned by NASA, to verify and study life forms, and for caution in current plans for returning a Mars sample to Earth. 

Under its motto, "Technologies for Information and Health," Biospherics' mission is to provide guidance and products to improve the quality of life. In addition to its BioTechnology unit, the Company offers telecommunications and database management information, and proprietary environmental, food and medical innovations.  

Biospherics 
September 1, 1998: Living Earth microbes recovered from 1967 moon lander Surveyor 3 by Apollo 12 may the most significant thing ever found on the Moon. full story at NASA's Space Science News. 

Image of Martian River System:
http://www.aas.org/~abstract/dps98/sort/73.htm  

Category 3 - 3. Mars Geology and Geophysics August 11, 1998 

[3.73] Determining the Distribution of Subsurface H2O on Mars from Impact Crater Ejecta Morphologies C. Perez, N. G. Barlow (U. Central Florida). 

Most fresh Martian impact craters are surrounded by lobate ejecta patterns emplaced by fluidization processes. Two theories exist to explain how this fluidized pattern is emplaced: (a) impact into and vaporization of subsurface volatiles, and (b) atmospheric entrainment of ejecta. Based on the observation of a diameter - latitude correlation among different ejecta morphologies by Barlow and Bradley (1990), the first theory appears dominant in the formation of the Martian fluidized ejecta morphologies. 

We have instituted a study to determine if longitudinal variations in ejecta morphology occur, which will provide information about the distribution of subsurface ice vs liquid water reservoirs on Mars. We have completed the analysis for 0-30N, longitude 315W westward to 180W. We used Viking Orbiter imagery with about 100 m per px resolution. We found interesting relations within the study area, suggesting that longitudinal variations in ejecta morphology do exist and likely provide information about subsurface properties. We found double lobe (DL) crater, although normally quite rare within our study area, make up a larger percentage of ejecta craters in 20-30N 50-90W. This area corresponds with the depositional regions of several outflow channels, suggesting that DL craters form by impact into layered material from the river deposits. We found multiple lobe (ML) craters make up a larger percentage of ejecta craters between 0-25N, 315-10W. This corresponds to an area of heavily cratered ancient terrain and suggests that liquid water reservoirs are more prevalent here. The most common ejecta morphology is single lobe (SL). SL craters are proposed to form by impact into ice, indicating that subsurface ice is prevalent throughout our study region. Finally the radial ejecta morphology (Rd) is more common around craters in the Tharsis region, suggesting that drier material is found around the volcanoes. 

Category 3. 3. 
Mars Geology and Geophysics August 11, 1998 3.50 
The "Face on Mars" at Cydonia: Natural or Artificial?
T. Van Flandern (Meta Research)

3.59 The Existence of Isolted Crater Clusters on Mars
N. G. Barlow (U. Central FL)

3.73 Determining the Distribution of Subsurface H2O on Mars from Impact Crater Ejecta Morphologies
C. Perez, N. G. Barlow (U. Central Florida)

3.129 TES Observations of the South Pole
T. N. Titus (Oak Ridge Associated Universities), H. H. Kieffer, K. F. Mullins (U.S. Geological Survey)

3.131 A First Look at Thermal Inertia from Mars Global Surveyor
M. T. Mellon, B. M. Jakosky (University of Colorado), H. H. Kieffer (U.S. Geological Survey), P. R. Christensen (Arizona State University)

3.178 The Color of Mars: Oxidation of Exogenic Metallic Iron
A. S. Yen, B. C. Murray (Caltech)

3.195 The Biological Potential of Mars, the Early Earth, and Europa 
B.M. Jakosky (Univ. of Colorado), E.L. Shock (Washington Univ. at St. Louis)

3.271 HST STIS and NICMOS Observations of Mars During 1997
J.F. Bell, III (Cornell Univ.), M.J. Wolff (Space Sciences Inst.), R.L. Comstock (Central Washington Univ.), P.B. James (Univ. Toledo)

3.331 A model for the chemical deposition of minerals in an evaporation basin on early Mars
David C. Catling (NASA Ames Research Center)

3.337 Mars Delay-Doppler Radar Observations with GSSR: 10 Year Review
A. F. C. Haldemann, R. F. Jurgens, M. A. Slade (JPL/Caltech, MS 238-420, Pasadena, CA 91109-8099), F. Rojas (Univ. Arizona, Tucson, AZ 85719), T. W. Thompson (JPL/Caltech, MS 300-227, Pasadena, CA 91109-8099)

3.370 Mariner 7 IRS Revisited: Evidence for Goethite on Mars
L. E. Kirkland (Lunar and Planetary Inst. / Rice U), K. C. Herr (Aerospace Corp.)

3.413 A Unique Mars Analog Site: The Haughton Impact Crater and Surroundings, Devon Island, Canadian High Arctic
P. Lee, A. P. Zent (NASA Ames Research Center)

3.415 Mars: New Results on History and Erosion/Deposition Conditions From Mars Global Surveyor
W. K. Hartmann (Planetary Science Institute)

3.450 Characterization of Dark Streaks on Martian Slopes
L. K. Fenton (California Institute of Technology), G. E. Danielson (Jet Propulsion Laboratory), A. Albee (California Institute of Technology)

3.461 Low Spatial Resolution Mars Global Surveyor Thermal Emission \\ Spectrometer Imaging Spectroscopy Maps of Mars: A Global Perspective  
R.N. Clark, T.M. Hoefen (USGS), R. Pearson (USBR), N. Gorelick, P. Christensen (ASU)

3.500 Mars Orbiter Camera: The First Year 
Michael Malin (Malin Space Science Systems) 

DPS Meeting, Madison 

Category 3 - 3. Mars Geology and Geophysics August 11, 1998 

[3.331] A model for the chemical deposition of minerals in an evaporation basin on early Mars 
David C. Catling (NASA Ames Research Center) 

Geological features on the surface of Mars seem to indicate an earlier epoch of sustained hydrological activity during the Noachian period [1]. Given the lower luminosity of the Sun at this time, liquid water would require a much larger greenhouse effect than the present atmosphere provides, and it has been widely hypothesized that this was most probably caused by a higher partial pressure of carbon dioxide (pCO2) in the early atmosphere [2,3,4,5]. Minerals forming in evaporite basins on Mars [6] may act as tracers of this early atmosphere [7]. Furthermore, it is possible that evaporitic minerals from this period and later epochs may be present in Martian meteorites [8,9]. 

Aqueous thermodynamic calculations are used to investigate the solute fractionation in a closed basin resulting from sequential evaporation. The model calculates the endogenic precipitates in a water column including carbonates and other minerals. The basin is assumed to be fed initially with terrigenous stream-water containing ions derived from the weathering of young ultramafic volcanic rocks in a thicker CO2 atmosphere. Siderite (FeCO3), the most insoluble of the major carbonates, is always the first carbonate to precipitate, provided the atmospheric pCO2 level exceeds \approx 0.1~bar. In conditions of seasonal water supply and evaporation, siderite varves would be an important facies component in early Martian sediments. Generally, a carbonate sequence of siderite, calcite/dolomite and hydromagnesite interspersed with silica (chert) is predicted, followed by gypsum and highly soluble salts like halite. Higher pCO2 causes gypsum precipitation earlier in the sequence at the expense of calcite. In ice-covered lakes, super saturation of trapped CO2 [10] may lead to little calcite and much gypsum. Further development of such models is important for interpreting future insitu mineralogy from landers and rovers, returned samples, and remote sensing results. 

{bf REFERENCES}:

[1] M. H. Carr (1996) {\it Water on Mars}, Oxford University Press.

[2] J. B. Pollack et al. (1987) {\it Icarus}, 71, 203-224.

[3] J. F. Kasting (1991), {\it Icarus}, 94, 1-13.

[4] F. Forget and R. T. Pierrehumbert (1997) {\it Science}, 278, 1273.

[5] Y. L. Yung et al. (1997) {\it Icarus}, 136, 222-224.

[6] R. D. Forsythe and J. R. Zimbelman (1995) {\it J. Geophys. Res.}, 100, 5553-5563.

[7] D. C. Catling (1998), LPSC XXIX, 1568-1569.

[8] J. C. Bridges and M. M. Grady (1998) LPSC XXIX, 1399-1400.

[9] P. H. Warren (1998) {\it J. Geophys. Res.}, 103, 16759-16773.

[10] D. Anderson et al. (1998) {\it Antarctic Science}, 10, 124-133. 

Category 3 - 3. Mars Geology and Geophysics August 11, 1998 

[3.178] The Color of Mars: Oxidation of Exogenic Metallic Iron
A. S. Yen, B. C. Murray (Caltech) 

The origin of the maghemite inferred to be present in the Martian soil by the Pathfinder and Viking magnetic properties experiments remains uncertain. Recent experimental results show that metallic iron can be oxidized into maghemite and hematite under conditions similar to the current Martian environment. 

These data suggest that non-aqueous weathering of meteoritic iron could be the source of the pigmenting oxides in the soils on Mars. The discovery of 1% to 7% of a magnetic mineral, believed to be maghemite, by the Viking Landers [1] was confirmed by Pathfinder [2]. The conventional explanation for the origin of the ferric oxides on Mars is based on the dissolution and subsequent oxidation of ferrous iron from silicate minerals in aqueous environments [e.g., 3]. We present the idea that oxides of exogenic, rather than locally derived, iron could be responsible for the Mars surface spectra. This concept is not new [4], but here we introduce a pathway for oxidation without liquid water. New experiments which monitor the conductivity of electron-beam evaporated Fe show that metallic iron can be efficiently converted to oxide in the presence of ultraviolet radiation and oxygen. Analyses of the resulting oxide phases by FTIR techniques show both maghemite and hematite. A test of the meteoritic origin of at least some of the iron at the Martian surface can be conducted with a measurement of the Ni content of the soil. Assuming an average of 7% Ni in iron meteorites and assuming roughly a quarter of the Fe at the Martian surface is exogenic, 0.1% to 0.5% Ni should be present in the surface soil. 

[1] Hargraves et al., JGR, 82, 4547-4558, 1977.

[2] Hviid et al., Science, 278, 1768-1770, 1997.

[3] Burns, Geochimica et Cosmochem. Acta, 57, 4555-4574, 1993.

[4] Gibson, Icarus, 13, 96-99, 1970. 

Category list 

Category 3 - 3. Mars Geology and Geophysics August 11, 1998 

[3.370] Mariner 7 IRS Revisited: Evidence for Goethite on Mars
L. E. Kirkland (Lunar and Planetary Inst. / Rice U), K. C. Herr (Aerospace Corp.) 

Spectra acquired by the 1969 Mariner Mars 7 Infrared Spectrometer (IRS), spanning the wavelength region 1.8-14.4µm, have recently been recovered and calibrated (Kirkland {\it et al}. LPSC XXIX abs. 1516, 1998). Absorptions detected at 2.4, 3, 11.25, and 12.5µm provide strong spectral evidence for the presence of a hydrous weathering product on the Martian surface, interpreted to be goethite. The 11.25 and 12.5µm bands do not correlate with atmospheric path length, neither do they correlate with 12.6µm atmospheric CO2 band depth, or the 9µm atmospheric dust band depth. Thus we ascribe the 11.25 and 12.5µm bands to the surface. An in-depth examination of the 2.4 and 3µm band strengths must await completion of the more comprehensive calibration that is currently in progress. The presence of a hydrous weathering product is geologically significant and has important implications for the present and past climate on Mars. These spectral features are consistent with spectra recently returned by the Mars Global Surveyor Thermal Emission Spectrometer (TES), covering 6-50µm. IRS and TES have similar spectral resolution in the ~10 to 13µm region. The 11.25 and 12.5µm bands may be examined in IRS spectra directly, but the lower spectral sampling of TES precludes a direct examination of the 12.5µm band without an atmospheric removal. However, TES spectra exhibit a band at 11.25µm that matches very well the feature in IRS spectra. Furthermore, TES spectra show a 23µm band, and this is consistent with the goethite interpretation. 

SOURCE: Harry Mason