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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."

GPS jammers send out a radio signal that’s the same frequency as the satellite signal. Since GPS satellite signals are weak, a GPS jamming device that puts out approximately 2 watts is sufficient to disrupt a GPS signal in a vehicle that’s approximately within 10 feet of the device. This leaves the in-vehicle system unable to establish its position and report back to a GPS tracking center, where the vehicle is registered. There are also fears that terrorists can use these devices to disrupt air traffic and cause severe safety and economic damage to the US. More powerful jammers could disrupt GPS signals in close proximity of airports, causing safety concerns. Our military overseas use GPS extensively to record their position as well as the position of the enemy. With GPS jamming devices in the hands of our enemy, U.S. and allied forces can be severely impacted when launching ground and air-strikes.