44th Lunar and Planetary Science Conference (2013) 1411.pdf RADAR IMAGERY OF THE CHRYSE–XANTHE REGION, MARS. J. K. Harmon, Harmon Space Science, 1902 Cacique St., San Juan, PR 00911,
[email protected]. Introduction: Earth-based radar imagery of Mars is particularly interesting, especially as the affected has been used to map regions of enhanced small-scale region seems to include the VL-1 lander site (H). (sub-meter) surface roughness based on the brightness Central Chryse and Bright Craters: Central and of the depolarized echo component. Although most northern Chryse shows moderate depolarized bright- bright depolarization features are associated with lava ness attributable to rocky outwash from the various flows in the major volcanic provinces [1,2], some ap- southern and western channels draining into the basin, parently non-volcanic bright features were also seen in although the deposits are probably sparser than those early (pre-upgrade) Arecibo imagery of the Chryse– in the brighter Maja outwash region of southwest Xanthe region [3]. Here I present updated imaging Chryse. Superimposed on the general background results for Chryse–Xanthe and environs based on ob- brightness of the region are numerous bright and dark servations made with the upgraded Arecibo radar dur- features associated with impact craters. The dark fea- ing the 2005 and 2012 Mars oppositions. I describe tures are mostly associated with “dark-halo craters” four specific subregions where bright depolarization such as those seen in Mars’ volcanic regions [2] as features appear to be signatures of aqueous deposi- well as the Moon, Venus, and Mercury. The bright tion/modification or other effects peculiar to the features are associated with “bright-ejecta craters” of a unique Chryse–Xanthe channel region.