Mapping Northern Vesta Quadrangle V-5NW: Investigating Crater Degradation and Ancient Structures

NASA's Dawn spacecraft arrived at the asteroid 4Vesta on July 15, 2011, and is now collecting imaging, spectroscopic, and elemental abundance data during its one-year orbital mission. As part of the geological analysis of the surface, a series of 15 quadrangle maps are being produced based on Framing Camera images (FC: spatial resolution: ~65 m/pixel) along with Visible & Infrared Spectrometer data (VIR: spatial resolution: ~180 m/pixel) obtained during the High-Altitude Mapping Orbit (HAMO). This poster presentation concentrates on our geologic analysis and mapping of quadrangle V-5NW. This quadrangle, located between ~20-66 N and 270-360 E, consists of an ancient terrain dominated by several large craters and many smaller ones, in which the large craters show evidence of mass movement downslope partially filling their interiors. This quadrangle also contains some dark material extending from quadrangle V-10EW to the south, which could be basaltic ejecta or partially buried basaltic volcanic materials, among other possibilities. The NE corner of this quadrangle is cut by heavily-modified ridges and troughs (grooves), perhaps part of a system of ancient structures that cut across a large portion of the northern hemisphere. Further detailed study is required to determine if these northern hemisphere structural features are associated in any way with the formation of the putative south polar impact structure. Acknowledgement: The authors acknowledge the support of the Dawn Science, Instrument and Operations Teams.