Dave Coppedge is back to blogging and on what better than planet theories (formerly a Cassini [Saturn] mission specialist), “Planet Theories vs. the Evidence” (Creation-Evolution Headlines, April 26, 2012 ):
Mars: The dry-Marsers scored more points over the wet-Marsers this month. In Nature News (April 11), Eric Hand wrote an article entitled, “Dreams of water on Mars evaporate: Climate models reveal the red planet was mostly cold and dry.” The pendulum has swung back to the dry-Marsers:
Last month, Jim Head, a planetary scientist at Brown University in Providence, Rhode Island, threw a wet blanket on the idea that Mars was ever very wet at all, in a keynote talk at the Lunar and Planetary Science Conference in The Woodlands, Texas. Head and others are assembling a picture of a Mars that was cold and dry from the beginning, punctuated at most by short bursts of wetness. “The notion of a palm-tree-covered Mars has waned,” says Stephen Clifford, a planetary scientist at the Lunar and Planetary Institute in Houston, Texas, who is organizing a conference in May on the early climate of Mars.
Head’s “revisionism” is driving Mars lifers into hiding: “[Jeff] Andrews-Hanna [Colorado School of Mines] says the shift in thinking doesn’t rule out life on ancient Mars, but instead drives it deeper underground.”
A paper in Science today (27 April 2012: Vol. 336 no. 6080 pp. 449–452, DOI: 10.1126/science.1219437) doesn’t need Martian water, either. Strange-looking polygons and coils in Athabasca Valles were explained by Phil Christensen and Andrew Ryan as artifacts of lava flows. The spiral coils found by Ryan on HiRise photos from the Mars Reconnaissance Orbiter (see photo on National Geographic News) are like fossil eddies created by shear stress in the flowing pahoehoe lava (see Science Daily). They don’t require water or ice for their formation. Moreover, they formed quickly: More.