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P. S. Cobian (Calif. State Univ. San Bern), F. Vilas (NASA JSC), S. M. Lederer (Calif. State Univ. San Bern.), N. G. Barlow (NAU)
Recent radar observations of the Mercurian N pole by Harmon et al. (Icarus 149, 2001) have pinpointed many additional radar bright areas with a resolution 10x better than previous radar measurements, and which correlate with craters imaged by Mariner 10. These craters are correlated with regions that are permanently shaded from direct sunlight, and are consistent with observations of clean water ice. In 1999, following the initial discovery of the radar bright craters near both poles of Mercury, Barlow et al. (Icarus 141, 1999) measured the depth-to-diameter (d/D) ratios of 170 impact craters in Mariner 10 images covering four different regions on Mercury’s surface. Rapid softening of crater structure, indicated by lower d/D ratios, could indicate the possibility of subsurface water ice in Mercury's terrain originating from an internal source in the planet. Their study included 3 specific radar bright craters suggested to contain ice. They concluded that no terrain softening was apparent, and a rapidly emplaced exogenic water source was the most likely source for the proposed ice in these craters. We have expanded the initial study by Barlow et al. to include d/D measurements of 12 craters newly identified as radar bright at latitudes equatorward of +85o. We compare our results to the statistical results from Barlow et al. here.
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Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.