Mars Water Debate Still Rages

[alexblackwell]

2004 American Geophysical Union Fall Meeting<br />December 13-17, 2004<br />San Francisco, CA<br /><br />The abstracts are now online. Note the Planetary Sciences section.

 

[fangsheath]

Again you have come through, Alex, you have my utmost appreciation.<br /><br />I found the Helbert and Benkhoff abstract to be one of the most intriguing. Here is an excerpt:<br /><br />"One of the scenarios we have looked at is a low thermal conductivity dust layer on top of a sand layer with a significantly higher thermal conductivity. Such configurations can be found for example in the Terra Arabia region. For this case we observed the formation of an ice lens at the boundary between the dust/sand material, effectively closing the pore space and significantly reducing downward diffusion. This leads to an actual enrichment of ice compared to the initially assumed mass of more than 50% within the dust layer. Results depend on the thickness and the parameters used of the layers. We will discuss the implication of such a scenario on our understanding of ice on Mars. The ice enriched layer might lead to an overestimation of the global ice inventory based on GRS and HEND measurements. The process of enriching the ice significantly slows the movement of the ice table to greater depth and can therefore stabilize ice over several thousands of years close to the surface. This implicates that we might indeed observe today the remains of the last Martian ice ages, but the assumed amount of ice moved across the planet can be significantly smaller than previously thought. Furthermore some of the "young" glacial feature one see today would have been formed not during, but after the last ice age and might even exist until today."

 

[alexblackwell]

Here's a peripherally-related, though nonetheless interesting, paper in press with the journal <i>Icarus</i>:<br /><br /><b>Paleo-pole positions from martian magnetic anomaly data</b><br /><i>Icarus</i>, In Press, Corrected Proof, Available online 8 October 2004<br />James J. Frawley and Patrick T. Taylor<br />Abstract

 

[alexblackwell]

Space Resources Roundtable VI<br />November 1–3, 2004<br />Colorado School of Mines<br />Golden, Colorado<br /><br />Program w/Embedded Links to Abstracts

 

[alexblackwell]

From the October 28, 2004 issue of <i>Nature</i>:<br /><br /><b>Recent ice-rich deposits formed at high latitudes on Mars by sublimation of unstable equatorial ice during low obliquity</b><br />Benjamin Levrard, François Forget, Franck Montmessin & Jacques Laskar<br /><i>Nature</i> <b>431</b>, 1072-1075, (2004). <br />doi:10.1038/nature03055<br />First paragraph<br /><br />See also "Severe glacial cycles on Mars."

 

[alexblackwell]

Published online today in the <i>Journal of Geophysical Research-Planets</i>:<br /><br />Leverington, David W.<br /><b>Volcanic rilles, streamlined islands, and the origin of outflow channels on Mars</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E10, E10011<br />10.1029/2004JE002311<br />28 October 2004<br />Abstract

 

[alexblackwell]

<i>Vernadsky Institute - Brown University Microsymposium 40<br />Topics in Comparative Planetology <br />October 11-13, 2004 Vernadsky Institute, Moscow, Russia</i><br /><br />The Program and Abstracts are now online.

 

[alexblackwell]

From the October 2004 issue of <i>Earth-Science Reviews</i>:<br /><br />Mars chronology: assessing techniques for quantifying surficial processes<br />Peter T. Doran, <i>et al</i>.<br /><i>Earth-Science Reviews</i> <b>67</b>, 313-337 (2004).<br />Abstract

 

[alexblackwell]

Two new interesting papers in press with the journal <i>Planetary and Space Science</i>:<br /><br /><b>Martian northern polar cap: Layering and possible implications for radar sounding</b><br /><i>Planetary and Space Science</i>, In Press, Corrected Proof, Available online 28 October 2004<br />Yaroslaw A. Ilyushin<br />Abstract<br /><br /><b>Thermal isostasy and deformation of possible paleoshorelines on Mars</b><br /><i>Planetary and Space Science</i>, In Press, Corrected Proof, Available online 28 October 2004<br />Javier Ruiz, Alberto G. Fairén, James M. Dohm and Rosa Tejero<br />Abstract

 

[exoscientist]

<blockquote><font class="small">In reply to:</font><hr /><p>Vernadsky Institute - Brown University Microsymposium 40 <br />Topics in Comparative Planetology <br />October 11-13, 2004 Vernadsky Institute, Moscow, Russia <br /><br />The Program and Abstracts are now online. <br /><br />Alex R. Blackwell <br />University of Hawaii<p><hr /></p></p></blockquote><br /><br /> Thanks for the links! Lots of great articles here!<br /><br /><br /> Bob <div class="Discussion_UserSignature"> </div>

 

[alexblackwell]

Great Debate<br />Larry Klaes<br /><i>Ithaca Times</i><br />November 3, 2004<br /><br />Note that Shinbrot <i>et al</i>. published their work in the June 8, 2004 issue of the <i>Proceedings of the National Academy of Sciences</i>:<br /><br /><b>Dry granular flows can generate surface features resembling those seen in Martian gullies</b><br />Troy Shinbrot, N.-H. Duong, L. Kwan, and M. M. Alvarez<br /><i>Proc. Nat. Acad. Sci</i>. <b>101</b>, 8542-8546, (2004); published online before print May 28, 2004, 10.1073/pnas.0308251101<br />Abstract<br />Supporting Information<br /><br />See also "Dust rocks martian river theory."

 

[alexblackwell]

Guy Webster (818) 354-6278<br />Jet Propulsion Laboratory, Pasadena, Calif. <br /><br />Donald Savage (202) 358-1547<br />NASA Headquarters, Washington, D.C.<br /><br />News Release: 2004-269 <br /><br />November 4, 2004<br /><br />Spirit Adds Clues About History of Rocks in Martian Hills<br /><br />All the scientific tools on NASA's two Mars Exploration Rovers are still working well, a full 10 months after Spirit's dramatic landing.<br /><br />The ones on Spirit are adding fresh evidence about the history of layered bedrock in a hill the rover is climbing.<br /><br />"Our leading hypothesis is that these rocks originated as volcanic ash that fell from the air or moved in ground-hugging ash flows, and that minerals in them were altered by water," said Dr. Ray Arvidson of Washington University, St. Louis, deputy principal investigator for the mission.<br /><br />"This is still a working hypothesis, not a firm conclusion, but all the instruments have contributed clues that fit," he said. "However, it is important to point out that we have just begun to characterize the textures, mineralogy and chemistry of these layered rocks. Other hypotheses for their origin focus on the role of transport and deposition by water. In fact, it may turn out that volcanism, water and wind have produced the rocks that Spirit is examining. We are just beginning to put together the big picture."<br /><br />Both rovers completed three-month primary missions in April. NASA has extended their missions twice because they have remained productive longer than anticipated.<br /><br />"We're still making good progress even though Spirit has two types of problems with its wheels," said Jim Erickson, rover project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We are working around those problems successfully, but they might be a sign of things to come, as mechanical parts wear out during our exploration of

 

[alexblackwell]

From the October 2004 issue of <i>Today's Chemist at Work</i>:<br /><br /><b>Spirit and Opportunity: Mössbauer on Mars</b><br />Michael J. Felton<br /><i>Today's Chemist at Work</i>, 18-24, (October 2004).<br />236.5 Kb PDF

 

[alexblackwell]

Published online today in the <i>Journal of Gephysical Research-Planets</i>:<br /><br />Byrne, S.; Ivanov, A. B.<br /><b>Internal structure of the Martian south polar layered deposits</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E11, E11001<br />10.1029/2004JE002267<br />09 November 2004<br />Abstract

 

[alexblackwell]

Published online today in <i>Geophysical Research Letters</i>:<br /><br />Jerolmack, Douglas J.; Mohrig, David; Zuber, Maria T.; Byrne, Shane<br /><b>A minimum time for the formation of Holden Northeast fan, Mars</b><br /><i>Geophys. Res. Lett</i>., Vol. 31, No. 21, L21701<br />10.1029/2004GL021326<br />10 November 2004<br />Abstract

 

[alexblackwell]

Workshop on the Role of Volatiles and Atmospheres on Martian Craters<br />July 11–15, 2005<br />Laurel, Maryland<br /><br />First Announcement<br />

 

[alexblackwell]

Mars Gullies Likely Formed By Underground Aquifers <br />By Leonard David<br />Senior Space Writer<br />posted: 12 November 2004<br />08:00 am ET

 

[thermionic]

A strong statement from that little article:<br /><br />"The discovery of hundreds of recent water-carved gullies on Mars indicates liquid water can be found at various depths in a wide array of locations, Stoker said. "<br /><br />Is this credible?<br />

 

[alexblackwell]

<i>Is this credible?</i><br /><br />The "discovery" to which Carol refers is certainly "credible," and well-known, too. The real question centers on what the discovery "indicates." And this question is not one of credibility, but of <i>plausibility</i>.

 

[alexblackwell]

Published online today in the <i>Journal of Geophysical Research-Planets</i>:<br /><br />Smrekar, S. E.; McGill, G. E.; Raymond, C. A.; Dimitriou, A. M.<br /><b>Geologic evolution of the Martian dichotomy in the Ismenius area of Mars and implications for plains magnetization</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E11, E11002<br />10.1029/2004JE002260<br />13 November 2004<br />Abstract

 

[thechemist]

"Water from a Stone" <br />Astrobiology Magazine.<br />featuring an interview with David Bish, Haydn Murray Chair of Applied Clay Mineralogy at Indiana University and co-author of the recent Mg sulfates Nature study.<br /><br />"Summary (Nov 15, 2004): <i>One question that has puzzled planetary scientists is where is the water on Mars today? One answer that is being investigated is mineral storage, particularly hydration of magnesium sulfate salts. If these storehouses protect water from evaporation, a second set of questions arise as to whether their delicate balance between temperature, pressure and humidity could be controlled on any future sample return mission. One priority for future Mars missions is bringing some pristine rocks home during a six months or longer martian journey.</i>" <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[alexblackwell]

From the December 2004 issue <i>Planetary and Space Science</i>:<br /><br /><b>Thermal isostasy and deformation of possible paleoshorelines on Mars</b><br />Javier Ruiz, Alberto G. Fairén, James M. Dohm and Rosa Tejero<br /><i>Planet. Space Sci</i>. <b>52</b>, 1297-1301, (2004)<br />Abstract<br /> <br /><b>Numerical slope stability simulations of the northern wall of eastern Candor Chasma (Mars) utilizing a distinct element method</b><br />B. Imre<br /><i>Planet. Space Sci</i>. <b>52</b>, 1303-1319, (2004)<br />Abstract

 

[alexblackwell]

Mars Express 'divining rod' mission delayed<br />18:33 08 October 04<br />NewScientist.com news service

 

[alexblackwell]

There is a new preprint available in <i>JGR-Planets in Press</i>:<br /><br /><i>Marinova, Margarita; McKay, Christopher; Hashimoto, Hirofumi</i>, — November 2004<br /><b>Radiative-convective model of warming Mars with artificial greenhouse gases</b><br />(2004JE002306)<br />PDF [0.3 MB]<br /><br />Note: I believe <i>JGR-Planets in Press</i> is available to non-subscribers.

 

[alexblackwell]

<i>Published online today in the <i>Journal of Gephysical Research-Planets</i>:<br /><br />Byrne, S.; Ivanov, A. B.<br /><b>Internal structure of the Martian south polar layered deposits</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E11, E11001<br />10.1029/2004JE002267<br />09 November 2004<br />Abstract</i><br /><br />For those without access to <i>JGR-Planets</i>, an ~2.26 Mb PDF reprint is available.