LARGE SCALE STRUCTURAL FEATURES ON 4VESTA

Images of 4Vesta taken by the Framing Camera (FC) instrument on the Dawn spacecraft reveal the presence large scale structural features on the surface of the asteroid. We map these structures directly onto the Vesta shape model, using the Small Body Mapping Tool (SBMT). The structures can thus be modeled to define planes that cut through the asteroid and the pole of the plane described by each individual lineament can be determined. We then compare the poles of the lineaments to determine if they are similarly oriented or if visual identification is confused by the shape of the asteroid.

Structural features include an equatorial set of wide flat floor troughs, bounded by steep scarps, which we interpret to be graben. A set of smaller, groove-type structures are identified on the floor of the South Polar Feature; these structures appear to trend along a north-south line projecting from the central hill. Analysis of these structures will contribute to our knowledge of the stress history of 4Vesta and may support models for the formation of the South Polar Feature.

Acknowledgement: The authors acknowledge the Framing Camera team, as well as the support of the Dawn Science and Operations Teams.