Mars Water Debate Still Rages

[rlb2]

From your above link<br /><br /><font color="yellow">Fairen and his colleagues looked at the available Mars data. But it was a river on Earth that caused the new idea to flow forth.<br /><br />Key to preventing carbonates from forming on both planets, according to the analysis, are certain concentrations of iron and sulfates, or salt. The study is detailed in the Sept. 23 issue of the journal Nature.<br /><br />"These ancient oceans probably lasted for near a billion years, totally covering the northern plains of the planet," he told SPACE.com. "Their chemistry was very different from those on Earth, and this is the reason why their existence has been so disputed: they left no Earth-like sediments, such as carbonate minerals."<br /><br />Iron and sulfur acidified the oceans, promoting a chemical evolution totally different to that in Earth's oceans, he said.<br /><br />Importantly, the Tinto River's acidic environment supports a rich biosphere.<br /><br />"Life is highly diverse in the Tinto system, allowing us to suggest comparable ancient acidic aquatic habitats hosting a putative early biosphere on Mars," Fairen and his colleagues write in the journal.<br /><br /><font color="orange">"In this scenario, the origin of life [on Mars] is a probable event," Fairen said.<br /></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>

 

[centsworth_II]

"These ancient oceans probably lasted for near a billion years....In this scenario, the origin of life [on Mars] is a probable event," Fairen said.<br /><br />I <b>like</b> this scenario! <div class="Discussion_UserSignature"> </div>

 

[alexblackwell]

From the September 24, 2004 issue of the journal <i>Science</i>:<br /><br />Solar Wind-Induced Atmospheric Erosion at Mars: First Results from ASPERA-3 on Mars Express<br />R. Lundin, <i>et al</i>.<br /><i>Science</i> <b>305</b>, 1933-1936, (2004)<br />Abstract

 

[alexblackwell]

There is a new preprint available:<br /><br />Martinez-Alonso, Sara; Jakosky, Bruce M.; Mellon, Michael T.; Putzig, Nathaniel — September 2004<br /><b>A volcanic interpretation of Gusev Crater surface materials from thermophysical, spectral, and morphological evidence</b><br />(2004JE002327)<br />PDF [7.51 MB]<br /><br />Note: I believe JGR-Planets in Press is available to non-subscribers.

 

[alexblackwell]

The latest issue of <i>Planetary and Space Science</i> (Volume 52, Issue 11, pp. 963-1071, September 2004), which is a special issue entitled <b>"Planet Mars. Sponsors: Centre National d'Etudes Spatiales (CNES); Centre National de la Recherche Scientifique (CNRS); Observatoire de Paris,"</b> is now online.

 

[alexblackwell]

Mars Global Surveyor<br />Mars Orbiter Camera<br />cPROTO Views of Spirit's Rover Tracks and Athabasca Vallis Flood Features<br />MGS MOC Release No. MOC2-862, 27 September 2004

 

[alexblackwell]

Note also that MSSS has updated the MOC Gallery with ~25,000 images.

 

[silylene old]

<i>cPROTO Views of Spirit's Rover Tracks and Athabasca Vallis Flood Features </i><br /><br />Wow!! That cPROTO picture of Spirit, Bonneville and the rovers tracks is amazing! I'd like to see some closeup pictures of the hills and highlands too.<br /><br />Even moreso, I wish we had cPROTO pictures of Opportunity and its travels. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[alexblackwell]

Mars Orbiter Sees Rover Tracks Among Thousands of New Images<br />September 27, 2004

 

[alexblackwell]

Mars Express latest findings give hints about water loss in the Martian atmosphere<br />27 September 2004

 

[alexblackwell]

From the October 2004 issue of <i>GSA Today</i>:<br /><br />Dilational fault slip and pit chain formation on Mars<br />David A. Ferrill, Danielle Y. Wyrick, Alan P. Morris, Darrell W. Sims and Nathan M. Franklin<br /><i>GSA Today</i> <b>14</b>, 4–12, (2004)<br />Full Text

 

[alexblackwell]

Published online today in <i>Geophysical Research Letters</i>:<br /><br />Feldman, W. C.; Head, J. W.; Maurice, S.; Prettyman, T. H.; Elphic, R. C.; Funsten, H. O.; Lawrence, D. J.; Tokar, R. L.; Vaniman, D. T.<br /><b>Recharge mechanism of near-equatorial hydrogen on Mars: Atmospheric redistribution or sub-surface aquifer</b><br /><i>Geophys. Res. Lett</i>., Vol. 31, No. 18, L18701<br />10.1029/2004GL020661<br />29 September 2004<br />Abstract

 

[alexblackwell]

Published online today in the <i>Journal of Geophysical Research-Planets</i>:<br /><br />Irwin, Rossman P., III; Watters, Thomas R.; Howard, Alan D.; Zimbelman, James R.<br /><b>Sedimentary resurfacing and fretted terrain development along the crustal dichotomy boundary, Aeolis Mensae, Mars</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E9, E09011<br />10.1029/2004JE002248<br />30 September 2004<br />Abstract<br /><br />Webb, Valerie E.<br /><b>Putative shorelines in northern Arabia Terra, Mars</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E9, E09010<br />10.1029/2003JE002205<br />30 September 2004<br />Abstract

 

[alexblackwell]

From the October 2004 issue of <i>Geology</i>:<br /><br />Schultz, Richard A., Chris H. Okubo, Cheryl L. Goudy and Scott J. Wilkins<br />Igneous dikes on Mars revealed by Mars Orbiter Laser Altimeter topography<br /><i>Geology</i> <b>32</b>, 889–892, (2004).<br />Abstract

 

[alexblackwell]

Published online today in <i>Geophysical Research Letters</i>:<br /><br />Lane, Melissa D.; Dyar, M. Darby; Bishop, Janice L.<br /><b>Spectroscopic evidence for hydrous iron sulfate in the Martian soil</b><br /><i>Geophys. Res. Lett</i>., Vol. 31, No. 19, L19702<br />10.1029/2004GL021231<br />02 October 2004<br />Abstract<br /><br />McEnroe, S. A.; Skilbrei, J. R.; Robinson, P.; Heidelbach, F.; Langenhorst, F.; Brown, L. L.<br /><b>Magnetic anomalies, layered intrusions and Mars</b><br /><i>Geophys. Res. Lett</i>., Vol. 31, No. 19, L19601<br />10.1029/2004GL020640<br />02 October 2004<br />Abstract

 

[alexblackwell]

<i>36th Annual DPS Meeting <br />Division for Planetary Sciences of the American Astronomical Society <br />November 8-12, 2004 <br />Louisville, KY</i><br /><br />The abstracts of the meeting are now online.

 

[bobvanx]

<font color="yellow">Spectroscopic evidence for hydrous iron sulfate in the Martian soil <br /></font><br /><br />This alternative explanation regarding the as-yet-undiscovered global carbonates looks credible. I'm trying to recall: Carbonates were a big deal because they would indicate more water rather than less water?<br /><br />If the hydrous iron sulfates are there, formed by weathering olivine in an acidic water environment, that keeps the water volume high, but shifts it away from an early carbonic sea to a sulfuric sea?<br /><br />For some reason, a Mars rich in iron and sulfur, but poor in carbon, catches my fancy.

 

[alexblackwell]

From the October 7, 2004 issue of <i>Nature</i>:<br /><br />Magnesium sulphate salts and the history of water on Mars<br />David T. Vaniman, David L. Bish, Steve J. Chipera, Claire I. Fialips, J. William Carey & William C. Feldman<br /><i>Nature</i> <b>431</b>, 663-665, (2004).<br />doi:10.1038/nature02973<br />First paragraph<br /><br />See also "Sopping salts could reveal history of water on Mars."

 

[alexblackwell]

Published online today in the <i>Journal of Geophysical Research-Planets</i>:<br /><br />Wilson, Sharon A.; Zimbelman, James R.<br /><b>Latitude-dependent nature and physical characteristics of transverse aeolian ridges on Mars</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E10, E10003<br />10.1029/2004JE002247<br />07 October 2004<br />Abstract<br /><br />Note: A 10 Mb PDF preprint is <i>temporarily</i> available.

 

[alexblackwell]

Donald Savage<br />Headquarters, Washington October 7, 2004<br />(Phone: 202/358-1727)<br /><br />Guy Webster<br />Jet Propulsion Laboratory (JPL), Pasadena, Calif.<br />(Phone: 818/354-6278)<br /><br />RELEASE: 04-342<br /><br />MARS ROVERS PROBING WATER HISTORY AT TWO SITES<br /><br />NASA's Spirit and Opportunity have been exploring Mars<br />about three times as long as originally scheduled. The more<br />they look, the more evidence of past liquid water on Mars<br />these robots discover. Team members reported the new findings<br />at a news briefing today.<br /><br />New findings raise the possibility Opportunity's work area<br />was soaked long ago, before it dried and eroded into a wide<br />plain. There are also signs some rocks may have gotten wet<br />again, after an impact excavated a stadium-size crater in the<br />plain.<br /><br />Evidence of this exciting possibility has been identified in<br />a flat rock dubbed "Escher" and some neighboring rocks near<br />the bottom of the crater. These plate-like rocks bear<br />networks of cracks dividing the surface into patterns of<br />polygons, somewhat similar in appearance to cracked mud after<br />the water has dried up here on Earth.<br /><br />Alternative histories, such as fracturing by the force of the<br />crater-causing impact, or the final desiccation of the<br />original wet environment that formed the rocks, might also<br />explain the polygonal cracks. Rover scientists hope a lumpy<br />boulder nicknamed "Wopmay," Opportunity's next target for<br />inspection, may help narrow the list of possible<br />explanations.<br /><br />"When we saw these polygonal crack patterns, right away we<br />thought of a secondary water event significantly later than<br />the episode that created the rocks," said Dr. John<br />Grotzinger. He is a rover-team geologist from the<br />Massachusetts Institute of Technology, Cambridge, Mass.<br />Finding geological evidence about watery periods in Mars'<br />past is the rover project's main goal, because such<br />p

 

[alexblackwell]

Published online today in <i>Science Express</i>:<br /><br /><b>Mars' South Polar Ar Enhancement: A Tracer for South Polar Seasonal Meridional Mixing</b><br />A. L. Sprague, W. V. Boynton, K. E. Kerry, D. M. Janes, D. M. Hunten, K. J. Kim, R. C. Reedy, and A. E. Metzger <br />Published online October 7 2004; 10.1126/science.1098496 (<i>Science Express</i> Reports)<br />Abstract<br />Supporting Online Material

 

[alexblackwell]

Published online today in the <i>Journal of Geophysical Research-Planets</i>:<br /><br />Montmessin, F.; Forget, F.; Rannou, P.; Cabane, M.; Haberle, R. M.<br /><b>Origin and role of water ice clouds in the Martian water cycle as inferred from a general circulation model</b><br /><i>J. Geophys. Res</i>., Vol. 109, No. E10, E10004<br />10.1029/2004JE002284<br />09 October 2004<br />Abstract

 

[alexblackwell]

There is a new preprint available:<br /><br />Irwin, Rossman; Howard, Alan; Maxwell, Ted — October 2004<br /><b>Geomorphology of Ma'adim Vallis, Mars, and Associated Paleolake Basins</b><br />(2004JE002287)<br />PDF [4 MB]<br /><br />Note: I believe <i>JGR-Planets in Press</i> is available to non-subscribers.

 

[qzzq]

From EurekAlert:<br /><br /><ul type="square">Telling a salty tale of martian water<br /><br />LOS ALAMOS, N.M., Oct. 7, 2004 – University of California scientists working at Los Alamos National Laboratory, along with a scientist from Indiana University have devised a method for determining whether sulfate salts can account for evidence of water on Mars. The work could pave the way to a better understanding of the martian environment and the history of water on Mars. <br />In a paper published in today's issue of the scientific journal Nature, a team of researchers lead by Los Alamos scientist David Vaniman describe the exposure of magnesium sulfate salts to various temperature, pressure and humidity conditions in order to understand their possible hydration states under martian surface conditions. The researchers discovered that the crystalline structure and water content of the salts are dependent on time-humidity history and that magnesium sulfate salts could retain sufficient water to explain at least a portion of the NASA Odyssey observations, which revealed surprisingly high abundances of near-surface hydrogen. <br /><br />According to Vaniman, "It's important to recognize that despite several unmanned missions to explore the geology of Mars, we still know relatively little about the martian environment and especially the history of water on Mars. This work is characteristic of the kind of knowledge base we need to create before humans ever travel to Mars, so that we can understand the martian world once we get there." The experiments examined the formation and transformation of magnesium sulfate minerals precipitated by evaporation from solutions and exposed in the solid state to controlled temperature and humidity conditions. The experiments included conditions that were slightly less than Mars atmospheric pressure, as well as other experiments conducted at temperatures fr</ul> <div class="Discussion_UserSignature"> <p> </p><p>***</p> </div>

 

[alexblackwell]

An interesting paper by Madden <i>et al.</i> was published in the October 14, 2004 issue of <i>Nature</i>. See<br /><br />Drought on Mars<br /><br />and<br /><br />Virginia Tech researchers suggest liquid water may have existed on Mars; findings published in Nature