The ability of NASA's Mars Reconnaissance Orbiter to continue charting the locations of these hidden glaciers and ice-filled valleys -- first confirmed by radar two years ago -- adds clues about how these deposits may have been left as remnants when regional ice sheets retreated.
The subsurface ice deposits extend for hundreds of kilometers, or miles, in the rugged region called Deuteronilus Mensae, about halfway from the equator to the Martian north pole. Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and colleagues prepared a map of the region's confirmed ice for presentation at this week's 41st Lunar and Planetary Science Conference near Houston.
The Shallow Radar instrument on the orbiter has obtained more than 250 observations of the study area, which is about the size of California.
"We have mapped the whole area with a high density of coverage," Plaut said. "These are not isolated features. In this area, the radar is detecting thick subsurface ice in many locations." The common locations are around the bases of mesas and scarps, and confined within valleys or craters.
Plaut said, "The hypothesis is the whole area was covered with an ice sheet during a different climate period, and when the climate dried out, these deposits remained only where they had been covered by a layer of debris protecting the ice from the atmosphere."
thinkahol * on 10 Feb 11The failure of social scientists to seriously question their own ideological and methodological assumptions contributes to the complex interrelationship between global ecological and individual psychological problems. Much of the literature on the tragedy of the commons focuses on saving the global commons through increased centralization and regulation, at the expense of the individual's autonomy and psychological sense of community. "Utopian" speculation in general and anarchist political analysis in particular are necessary correctives to misplaced attempts to merely rearrange the elements of the status quo rather than to radically alter it in a direction more in keeping with both survival and human dignity.
