Figure (a) Global mosaic of Magellan SAR imagery. Right-looking imagery fills voids in left-looking imagery. A quadtree of kml is used for rapid panning and zooming while images are delivered over the internet. (b) Zoom of area along the Artemis trench, which has similar topography and fracture patterns as the Aleutian trench on Earth [Sandwell and Schubert, 1992]. Trench and outer rise lines were digitized from the matching topography image (not shown). Artemis is an example of an enigmatic class of volcano-tectonic features on Venus [Stofan et al 1992], that are still poorly understood but that are likely a key to probing the surface, interior, and climate history of the planet.