High resolution Enceladus atlas derived from CASSINI-ISS images

Abstract

The Cassini spacecraft began its tour through the Saturnian system in July 2004. The Imaging Science Subsystem onboard the orbiter consists of a high-resolution Narrow Angle Camera (NAC) with a focal length of 2000 mm and a Wide Angle Camera (WAC) with a focal length of 200 mm [1]. One of the main objectives of the Cassini mission is to investigate the icy Saturnian satellites. Enceladus, the second innermost of the medium sized satellites, was imaged by the Cassini spacecraft during three close flybys [2]. The images taken during these flybys together with lower resolution frames allowed us to create a global mosaic of Enceladus with a spatial- resolution of about 110 m/pixel. Unfortunately, the Cassini ISS has not yet imaged the northern high latitude regions (> 67°) because they are shrouded in seasonal darkness and will not be illuminated by the Sun until later in the decade when the Cassini extended mission begins. Fortunately, the Voyager camera was able to take images from these regions during its flyby in the early 1980’s. We thus used Voyager images to fill the North Polar gaps in the global mosaic.